Bug o’the Week – Wetlands Month I – Crawling Water Beetle

Bug o’the Week
by Kate Redmond

Wetlands Month I Crawling Water Beetle

Howdy, BugFans,

May is National Wetlands Month, and the BugLady is celebrating by re-posting episodes about aquatic critters from deep in the BOTW archives (this one is from 2012, with some new words added).

The BugLady heard an interesting interview on the radio a while back in which the guest said that non-scientists are intimidated by the feeling that they must know the exact names of the plants and animals on their landscapes in order to discuss them, and that the belief that those names belong only to scientists causes people to become estranged from the natural world.  Yes and no.  While it is true that each organism has a scientific name that belongs to it alone and is universally recognized, the amazing world of common names is up for grabs.  Common names are the names bestowed by people, often regionally, who experience an organism where the rubber meets the road.  The more abundant or beloved or notorious or scary an organism is, the more common names it’s likely to have collected.

So – what to name a small, yellowish, spotted, aquatic beetle that scrambles through the water, head down, in perpetual motion?  That, rather than “rowing” its legs in synchrony like a water boatman, “dog-paddles,” moving its legs alternately, appearing to crawl through the water.  OK – Crawling water beetle it is.

There are almost 70 species of Crawling Water Beetles (family Haliplidae) in North America, divided up among four genera (this beetle belongs to the most common genus, Haliplus) (probably) – Haliplus, because the other common genus, Peltodytes, has two spots on the thorax, just north of the elytra (wing covers).  Identification to species can be tricky and gets very up close and personal.  A Crawling water beetle that’s ¼” long is a big Crawling water beetle.  Haliplids favor still, shallow water and the pool areas of streams and rivers everywhere (except Antarctica) (they favor temperate regions), and the BugLady read about an endangered Irish species that lives in tidal salt marshes.  Three of Wisconsin’s Crawling water beetle species are listed as rare.

Crawling water beetles that live in ponds and lake edges can be found scrambling through the water column or feeding in mats of aquatic plants, especially algae.  Where there is a current, look for them in crevices between rocks.  Unlike many of their aquatic brethren, Crawling water beetles are bulky (one source said “barrel-shaped”), mediocre swimmers that are not streamlined, and other than some long hairs on their back four feet, their legs are not adapted for swimming (they are weak fliers, too, on wings that are rolled – not folded – under the elytra when not in use). 

Their two hind legs are modified – but they’re modified for breathing.  The sections at the base of each hind leg (closest to the body) are greatly flattened to form “coxal plates” that meet under the beetle.  Together, the coxal plates cover part of the thorax and abdomen and create a second space to carry oxygen.  When it needs oxygen, a Crawling water beetle backs up to the surface film, takes in air, and stores it in an area on its back, above its abdomen and beneath its elytra.  A reserve supply is cached between the coxal plates and the lower surface of the abdomen, and it is in communion with the air under the elytra.  Insects take in air through breathing pores called spiracles, and there are spiracles located under the coxal plates. 

A bubble of air peeking out from under the elytra helps Crawling water beetle float to the water’s surface (a Crawling water beetle that’s low on air loses buoyancy and must clamber back up the vegetation).  The long, skinny Crawling water beetle larvae http://bugguide.net/node/view/327585 simply breathe through their skin and don’t develop spiracles until they are almost ready to pupate.   

There’s a lot of variation in Crawling water beetle larvae across the various genera https://bugguide.net/node/view/280859/bgimage

Crawling water beetles lay their eggs on submerged aquatic plants, especially filamentous algae.  Some excavate small holes in the plant tissue and lay their eggs inside.  The short-legged, hook-footed larvae creep about on algae mats, where they are well-camouflaged, playing dead when alarmed (alarmed adults make for the bottom of the pond and cling to plant stems there), feeding on their algal substrate with mouthparts that are adapted for grabbing algae, piercing its walls, and sucking out its juices.  Larvae that are too tiny to puncture the tough cell walls feed on the fungi and bacteria on the algae’s exterior.  Adults continue to feed on algae, but they add protein to their diet in the form of tiny invertebrates like worms, daphnia, and midge eggs.  They are eaten by fish, salamanders, and larger aquatic insects.

Crawling water beetle larvae pupate on the shore, in a cell they prepare under a rock or log near the water’s edge.  Their new-found spiracles allow them to breathe out of water.  Some species spend the winter as pupae; others emerge to spend the winter in the water as adults. 

Adults can be found in the water all year round, moving slowly under the ice in winter and congregating in deep spots where the photosynthesis of aquatic plants provides oxygen.  Larvae are seen in spring. 

Haliplids are among the many shy, retiring insects who live their lives off our radar, simply because their lives don’t impact ours in any economic way (“man is the measure of all things,” said the BugLady’s high school English teacher).

The BugLady photographs aquatic invertebrates as they swim around in a white, plastic spoon.  Crawling water beetles do not stop and pose.  Here are some better pictures https://bugguide.net/node/view/262970/bgpagehttps://bugguide.net/node/view/938881/bgimage.

Go outside.  Name stuff!

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – American Emerald Dragonfly

Bug o’the Week
by Kate Redmond

American Emerald Dragonfly

Greetings BugFans,

The dragonfly season is starting – migrant Common Green Darners and Variegated Meadowhawks https://bugguide.net/node/view/1888926/bgimage are filtering into the state, and visions of sugarplums (in the form of Chalk-fronted Corporals, Baskettails, and Eastern Forktails) are dancing in our heads!  June will see the first of the Emeralds (family Corduliidae).

Also called Green-eyed Skimmers (though the name Skimmer belongs more properly to a different family, Libellulidae), the Emerald family is a large and varied one (about 50 species in North America and 400 worldwide) that includes the bog haunters, emeralds, baskettails, sundragons, and shadowdragons.  Corduliids are found worldwide, and as a group, their ranges tend to be northerly.

They are medium to large (1 ½” to 3” long) dragonflies, and although they may be dark in coloration, many have metallic markings on their thorax and striking green eyes that touch on the top of their heads https://bugguide.net/node/view/1616593/bgimage.  Many species have a pale ring between the second and third abdominal segments.  When they perch (which is not often enough for dragonfly photographers), they tend to perch vertically, hanging from vegetation at a 45 degree angle. 

Every spring, the BugLady takes lots of pictures of the very spiffy Racket-tailed Emerald (Dorocordulia liberahttps://bugguide.net/node/view/1543225/bgimage, a species found commonly in the northeast quadrant of the continent.  She doesn’t see the larger, American Emerald (Cordulia shurtleffii) nearly as often – it’s more common near bogs, sedge marshes, forested lakes and ponds, and fens “Up North” and across much of Canada and the northern US.  Some American Emeralds have (slightly) flared abdomens, like the Racket-tailed Emerald does, but the yellow band at the top of the Racket-tail’s abdomen is thick and uneven compared to the American Emerald’s thin ring https://bugguide.net/node/view/255153/bgimage.  American Emeralds may resemble and overlap in size with some of the Striped Emeralds in the genus Somatochlora.  Here are some great pictures https://www.marylandbiodiversity.com/view/694.  

Adults eat soft-bodied insects that they grab out of the air, from mosquitoes to butterflies to mayflies to royal ants to recently-emerged dragonflies and damselflies.  They forage in woodland openings and edges and sometimes, early in the season, mingle with swarms of baskettails.  Paulson (Dragonflies and Damselflies of the East) reports that the American Emerald “sometimes hovers among plants in an effort to flush prey, often successful.” As befits a northern species, they are more active in cooler temperatures. 

Kurt Mead, in Dragonflies of the North Woods, tells us to “Look for the males’ ‘dart and hover,’ ‘dart and hover’ behavior as they patrol their shifting territories along boggy edges of small lakes and ponds.”  After mating https://bugguide.net/node/view/1476577/bgimage, a longish process carried out partially in flight, Mead says that “the female taps the surface of the water with her abdomen when laying eggs, often among sedges and other emergent vegetation.”  

The sturdy, hairy, aquatic naiads are “sprawlers,” hiding in the mud and under the debris trapped in their hairs, and ambushing their prey – scuds (freshwater shrimp), mosquito and midge larvae, mayfly nymphs, and the occasional tiny fish and tadpole – as it passes by.  They can tolerate pretty cold water, but in cold water they need more than one summer to mature.  They emerge to shed their final skin at night https://bugguide.net/node/view/524287/bgimage.  Here’s a teneral – a recently emerged adult – that has the reddish-brown eyes typical of a young emerald https://bugguide.net/node/view/1077403/bgimage.

The BugLady was curious about the American Emerald’s species name shurtleffii (ah – the etymology of entomology!), so she did a little digging.  The species was described by the renowned entomologist Samuel Scudder in 1866.  Scudder named it after a young physician named Carleton Atwood Shurtleff (1840 to 1864), a polymath whose interests included botany (native orchids) and entomology (he studied insect wing venation).  Shurtleff’s parents sent his collections and papers to the Boston Society of Natural History after his death in 1864 “from a disease contracted at the siege of Vicksburg.” Scudder read a paper by Shurtleff posthumously at a Society meeting and praised his achievements, and later immortalized him in a dragonfly’s name.    

Carpe diem (or as the BugLady’s t-shirt says, “Carpe Insectum.”)

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Oblique-banded Leafroller Moth

Bug o’the Week
by Kate Redmond

Oblique-banded Leafroller Moth

Greetings, BugFans,

The venerable (circa 1903) moth book that the BugLady grew up with – The Moth Book by W. J. Holland – included pictures of a huge number of moth species, all with wings outstretched, in pinned position.  Great for seeing all of the markings – not so great for showing the unique shapes and postures of many moths https://bugguide.net/node/view/889584/bgimage  https://bugguide.net/node/view/1307815/bgimage  https://bugguide.net/node/view/259944      https://bugguide.net/node/view/973408   https://bugguide.net/node/view/11941/bgimage   https://bugguide.net/node/view/427321/bgpage (the Peterson field guide portrays them as they perch).  Holland’s picture of today’s moth was a little odd.

Oblique-banded Leafrollers (OBLRs) are in the family Tortricidae (accent on the first and third syllables), sometimes called the Tortricid/tortrix, leaf roller, and leaf tier moths.  It’s a large group (10,000 species worldwide and 1,400 north of the Rio Grande) of small (wingspans of ½” to 1 ¼”), drab, bell/arrowhead-shaped moths, and even smaller caterpillars that are often green with dark heads.  Some species are agricultural pests (spruce budworm and a variety of apple-lovers), and a few species are used as biological controls to deal with unwanted plants.  Caterpillars of some Tortricid species bore into plant materials, and others feed on the exterior (and these caterpillars come equipped with a structure called an anal fork that allows them to flip their frass (bug poop) away from their bodies, so it won’t lead parasites or predators to them).  Some are generalist feeders and some limit their diets.  A few make galls.

OBLRs (Choristoneura rosaceana), aka Rosaceous Leaf Rollers, are a native species that lives throughout most of the US and into southern Canada (and that we have accidentally exported to other parts of the globe).  They’re habitat generalists, found from wetlands to woodlands to old fields to orchards.  The caterpillars, which are said to be the most common tortricid in North America, are hard to tell from related caterpillars, and when asked how to distinguish the notoriously variable adults from their relatives, a commentator in bugguide.net said, “Today I was asked how to separate species that look similar to Choristoneura rosaceana and thought I’d share my response here since it is commonly collected and frequently misIDed. The short answer is assume everything is C. rosaceana unless you have reason to believe otherwise. The longer answer is below and basically outlines my thought process.” 

There are no picky eaters here!  OBLM caterpillars feed on more than 80 species of plants, most, but not all of them, woody.  They’re especially fond of plants in the rose family, like cherry, apple, pear, chokecherry, raspberry, and peach, but they also eat maple, sumac, birch, honeysuckle, viburnum, oak, ash, buckthorn, willow, aspen, basswood, elm, pine, and more.  OBLRs are eaten by birds and a number of invertebrate predators, including some ladybugs.  Leaf rolling, leaf tying, and gall making benefit caterpillars that have lots of predators.

Because of its connection with commercial fruits, this is one well-studied insect; although much that is known about them is based on laboratory observations.

Courtship is driven by hormones and is formulaic– she “calls,” he responds, they sit head-to-head for a while, and things progress.  If she’s not interested, she leaves.  She deposits masses of wax-covered eggs (200 to 900, said one source) on the upper surfaces of host plants, and when the caterpillars hatch https://bugguide.net/node/view/1185427/bgimage, many disperse by spinning silk and taking off, like spiders, casting their fates to the winds (https://uwm.edu/field-station/bug-of-the-week/spider-flight/) – they bet the farm on avoiding aerial predators and landing on a host plant.    

There are two generations of OBLRs in Wisconsin, which works out to three waves of caterpillars.  OBLRs overwinter as partially-grown caterpillars, and when they emerge, they skeletonize the undersides of very new leaves or feed in the buds.  When the leaves get big enough, caterpillars make leaf shelters lined with silk https://bugguide.net/node/view/1039803/bgimage and later pupate in them.  The first crop of adults appears in June, and their eventual offspring https://bugguide.net/node/view/2336932/bgimage eat leaves and the surface of fruit https://bugguide.net/node/view/546919/bgimage.  The next adults are seen in late summer, and it’s their caterpillars that overwinter, in a hibernaculum that they spin between folded leaves, in twig crotches, under bud scales, or in bark, emerging as buds start to swell.  Depending on what time of the year they’re feeding, they cause the fruit to be pitted or deformed, and they may introduce rot that isn’t obvious until after harvest.  Mature and almost mature caterpillars do the most damage. 

ADDENDUM: The BugLady just read an interesting article in the New York Times about how scientists are noticing that fewer moths come in to light traps (previously the gold standard for capturing and censusing moths).  Why?  Fewer moths overall?  Not always – hormone traps (used by farmers to estimate numbers of crop pests) attract lots of them. 

Once upon a time, a contemporary of Charles Darwin’s asked him why moths are attracted to light (a topic that has attracted, in turn, a lot of scientists).  Darwin replied that “maybe it’s because lights are quite new and moths haven’t quite figured it out yet…. But you might expect that over time they will stop doing this.”  He may have hit the nail on the head. 

Avalon Owens, an entomologist at Harvard, explains, using corn earworms as an example: “It might be, as Darwin suggested, that evolution has removed moths with an attraction to light from the gene pool, so that today’s corn earworm moth is no longer as drawn to light.

But another explanation for the decline in light trap effectiveness might be that it’s a consequence of the world surrounding those light traps growing much brighter. With streetlights and spotlights and everything else lighting up the night, moths may not be noticing the light traps as much as they notice other glowing things.” 

Light pollution affects a lot of us – migrating birds, hatchling sea turtles, some fish, nocturnal predators, tree frogs, Monarch butterflies, fireflies – and people who just want to see the stars.

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Green Lacewings

Bug o’the Week
by Kate Redmond

Green Lacewings

Howdy, BugFans,

These lovely, fragile-looking insects have fluttered around the edges of several BOTWs over the past 17-plus years, and it’s time for them to have an episode of their own.

A bit about their pedigree: they are in the oddball order Neuroptera (“nerve-wing”), an order that’s undergone a fair amount of tinkering.  Presently, it’s home to the doodlebugs/antlions, the owlflies, and a whole bunch of different varieties of lacewings; and it’s the former home of the snake, alder, fish, and Dobsonflies (hellgrammites).  Neuropterans are soft-bodied insects with four, similarly-sized, conspicuously-veined wings, and chewing mouthparts, and they practice complete metamorphosis (going through egg, larva, pupa, and adult stages).  Their larvae are predators.

A note about Green lacewing taxonomy – members of the genus Chrysoperla are frequently encountered across North America, as are members of the genus Chrysopa.  They look a lot alike, their photographs can be confusing, and various species have been swapped back and forth between the two genera for a long time (and at one point, many species were lumped as a single species).  When the BugLady looks at the Green lacewing shots she’s taken over the years, a number of different species seem to be represented – pale dorsal stripes on some, small thoracic spots on others, no definitive markings at all on still others – so she will keep this general. 

Green lacewings are in the suborder Hemerobiiformia, which includes the Dusty, Pleasing, Beaded, Brown, Giant and Moth, Mantid, Spoon-Winged, and Spongilla lacewing families as well as the Green lacewing family Chrysopidae (from the ancient Greek words for “gold” and “face”).  They are also called Golden-eyed lacewings and “stinkflies” (because members of several genera release bad-smells when handled), and their larvae are known as aphid lions or aphid wolves. 

The “alligator-like” larvae live up to their nicknames, grabbing insects – including eggs, pupae, and caterpillars https://bugguide.net/ but especially aphids – with their sickle-shaped jaws, injecting them with a paralyzing venom, and sucking out the softened innards (https://bugguide.net/node/view/1182183/bgimage (which, in the case of an aphid, takes about 90 seconds).  They often hold their prey aloft as they’re draining it.  Some sources report that the larvae wave their abdomens back and forth as they roam the leaf tops, and others say that they swing their heads back and forth, seizing prey when they bump into it (their sense of touch is well-developed). 

It’s also said that some species can account for 100 to 200 aphids a week, and if they can’t find their normal quota of prey, they have no qualms about eating other lacewing larvae.  Depending on the species, adults may be predators, or they may be vegetarians that feed on nectar, pollen, and honeydew (the sugar water exuded by some bugs). 

Lots of insects and spiders eat lacewings.  Adults are nocturnal and are poor flyers, but they can hear the echolocation calls of bats and avoid them by folding their wings (presenting a smaller target) and dropping to the ground.  Some parasitic wasps search out lacewing cocoons and lay their eggs on them, and their larvae eat the cocoon’s contents.

Green lacewings court by “singing.”  Males vibrate their abdomen and send a signal out through the substrate, and females hear/feel his song through their legs and respond with their own, identical song, the pair singing part duet/part call-and-response.  Even though we may not be able to tell species apart visually, their songs differentiate them. 

Females make stalks by touching the underside of a leaf or twig with their abdomen and then pulling back, extracting a thread (manufactured in her reproductive system) that hardens immediately, and they place an egg on top of each stalk https://bugguide.net/node/view/2270799/bgimage (and some create a cool, spiral pattern https://bugguide.net/node/view/313076/bgimage).  Eggs are laid where there are aphids nearby.  It’s theorized that suspending the eggs protects them from predators, including their newly-hatched, immediately-hungry siblings.  About three weeks after hatching, mature larvae spin cocoons in the vegetation https://bugguide.net/node/view/765647/bgimage, and adults emerge about five days later.  There are several broods per year, and they overwinter as adults or as pupae. 

Some species of Green lacewings have hairy/spiny, “trash-carrying” larvae – larvae that stick debris – and sometimes bits of dead prey – to their backs, creating a shield that they present to aggressors.  Does the disguise help them avoid aphid-farming ants?  Hide them from predators?  Watch this very cool video: https://www.youtube.com/watch?v=fbRK6E5crbg.   

Because of their dining habits, lacewing larvae are sold as a biological control of aphids, the Catch 22 being that when they’ve finished eating the aphids or mature as adults, they may move on. 

A Note from the Pulpit: Because of their nocturnal habits, adult lacewings are often attracted to and killed by bug zappers.  The vast (vast) majority of insects killed by bug zappers (about 95% in one study and more than 99% in another) are NOT target species like mosquitoes and other biting flies (which are not attracted to the zapper’s UV light).  The vast (vast) majority are pollinators like moths, or predators like lacewings, or just innocent passers-by.  At a time when insect numbers are going down globally, and we recognize all the “ecosystem services” they provide (including feeding the birds), the idea of this degree of collateral damage is repugnant.

Fun Lacewing Facts (from the North Carolina State College of Agriculture and Life Sciences).

  • For many years, biologists thought their eggs were the fruiting bodies of a fungus they called Ascophora ovalis. The true nature of these eggs was first discovered in 1737 by Rene Reaumur, a French physicist, biologist and inventor.
  • As larvae, lacewings and antlions do not have a complete digestive system: the midgut ends in a dead end. Waste materials accumulate in the midgut throughout larval development and are finally expelled only after a connection is made with the anus near the end of the pupal stage. The accumulated fecal material is called a meconium. 

CICADA ADDENDA

Last week’s cicada story is the gift that keeps on giving.

ERRATUM: – the quote about cicadas mistaking people for trees, mistakenly attributed to the EPA, was actually from Cicada Mania.  The BugLady thought it sounded a bit un-EPA-ish, but she had just been on their site, and her brain hiccoughed.

AND ELABORATION – https://www.scientificamerican.com/article/long-overlooked-benjamin-banneker-is-recognized-for-work-on-cicadas-and-against-slavery/.  Thanks, BugFan Bob.

AND SUPER POWERS (Oh My!) – the wings of cicadas and a number of other groups like honey bees, butterflies, dragonflies and damselflies have what one scientists calls “anti-biofouling and antimicrobial” properties!  Not chemically antimicrobial but structurally antimicrobial.  How does that work?  The surface of the wings is covered with “nanopillars” – columnar structures with a diameter of about 100 nanometers (one-one thousandth the diameter of a human hair), with “spikey” tips.  Bacteria that land on them literally get impaled, tearing their cell walls, which kills them.  The nanopillars are (somehow) self-cleaning, getting rid of the debris that might serve as a medium for more bacteria to grow.  Scientists are hoping to copy the system https://www.sciencealert.com/cicada-wings-kill-superbugs-on-contact-and-we-may-finally-know-how.  Stay tuned.

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – The Cicadas are Coming – a Tale in Four Parts

Bug o’the Week
by Kate Redmond

The Cicadas are Coming a Tale in Four Parts

Greetings BugFans,

The insect world is gearing up to stage an event that is the entomological equivalent of the recent total solar eclipse.  The buzz (if you’ll pardon the term) began a few months ago with articles in the New York Times and the Smithsonian newsletter.  The event: the emergence of billions (with a “b”) of Periodical cicadas over a large chunk of the country south and east of Wisconsin.  What one entomologist calls a “spectacular, macabre Mardi Gras” and another calls “a David Attenborough show in your backyard.”

Part 1: SETTING THE STAGE

Young cicadas – nymphs – live underground, using their piercing-sucking mouthparts to feed on the fluid that’s getting pumped up into the tree from the roots.  The length of their subterranean stay is determined by their species (though sometimes over-enthusiastic individuals may jump the gun, and climate change may be affecting their internal chronometers). 

Most of Wisconsin’s cicada species are green and black, bullet-shaped Annual cicadas in the genus Neotibicen, the Dog-day cicadas https://bugguide.net/node/view/1588994/bgimage, who spend just a year or two underground as nymphs and then tunnel to the surface, climb something vertical, and emerge from their nymphal skin into adulthood (great photo series here https://bugguide.net/node/view/320141/bgimage).  If you’ve seen a nymph trekking across the lawn or climbing a post, you’ve been privileged to see something that looks, and is, prehistoric – they’ve been around for 200 million years.

Cicadas practice what the BugLady calls the “Normandy Beach” strategy of reproduction – throw enough soldiers on the beach and some will get through (real scientists call it “predator satiation”).  Cicadas emerge in large numbers into the waiting jaws, bills, claws, and skillets of a myriad of predators.  Another hypothesis involves predator avoidance.  The year after the cicadas are numerous, their predators’ populations peak, because they had all that food last year to feed to all those young, and survival rates were high.  The next year, prey is scarce, and predator numbers adjust themselves (a 13 or 17 year lag seems overly cautious, but there are Prime number variants of this theory that the BugLady is not equipped to explain).  Or it could be that cicadas developed this method to avoid hybridization.   

Part 2: PERIODICAL CICADAS (Magicicada sp.), aka 13 and 17 YEAR LOCUSTS. 

First off, they’re not locusts – locusts are in the Grasshopper order Orthoptera, and cicadas are in the Bug order Hemiptera.  Second, although most cicadas have relatively predictable nymphal periods, the genus Magicicada owns the name “Periodical cicada.”  North America has three species of 17-year cicadas and four species of 13-year cicadas (and of course, some cicada experts think that those seven Magicicada species might only be three species.  Stay tuned).  The ranges of the 17-year species are a bit more northern, and the 13-year species are a bit more southern.  Third, they’re pretty awesome-looking insects.  Many thanks to BugFan Tom for his wonderful pictures.

Magicicada is divided into 15 groups called Broods, each designated by a different Roman numeral.  Broods are defined not by species but by the synchronicity of their internal clocks, and most emergences involve more than one species https://www.cicadamania.com/cicadas/where-will-17-13-year-periodical-cicadas-emerge-next/.

Masses of male Periodical cicadas gather in the treetops and “sing” by vibrating an internal membrane (tymbal) that’s stretched between the thorax and the abdomen.  It vibrates hundreds of times per second and can, depending on the species, produce sounds of nearly 100 decibels (louder than a vacuum cleaner, leaf-blower, blender, or garbage disposal).  Between choruses, males make short flights away from the group looking for mates (she flicks her wings at him if she’s in the mood.  Female cicadas are silent, but even if she could make sound, he might not hear her in the din).  Females lay eggs by drilling into twigs, and when the egg hatches, the nymph (and often the tip of the twig) drops to the ground. 

Magicicada nymphs spend their lives about two feet underground, molting five times, and some researchers suggest that they note the passing years by registering that the tree sap is richer in amino acids when the tree blooms in spring (but they don’t know how cicadas “count”).  They are transient – starting to emerge at night, in late April, when soil temperature reaches 64 degrees F, and disappearing by mid-July.  By then, the nymphs have aerated the soil, the decomposing shells and adults are enriching the soil, and the birds are well-fed.

Conventional wisdom long held that adult cicadas lived briefly and didn’t eat, which wisdom the BugLady imparted to her offspring.  She got a phone call one day from one of her daughters, who was out on the trail with a class.  She had picked up a cicada to show them, and it had stabbed her in the finger (cicadas, the EPA says, “sometimes mistake us for trees,” and it advises us to “Just remove the cicada from your person, and go about your business”).  Adult cicadas feed on plant juices – in fact, they sip 300 times their body weight in plant sap daily. 

What goes in must come out, and along that vein, some recent articles have noted that because they must ingest so much nutrient-poor plant sap in order to get enough calories, cicadas are prodigious (and powerful) pee-ers and that no one has studied the impact of all that urine on the landscape (as we say in the Nature business – don’t look up with your mouth open).

Cicada nymphs are eaten by moles, and the adults provide a buffet for snakes, lizards, skunks, rodents, possums, birds of all sizes (the BugLady once heard a truncated cicada buzz and looked out the window to see a (smug) Brown Thrasher leaving the scene with a beakful of cicada), and they are collected and cached by Cicada-killer wasps https://bugguide.net/node/view/1456668/bgimage.  A few sources said that when birds concentrate on cicadas in big years, they ignore caterpillars, allowing caterpillar populations to increase.  Historically, American Indians fried or roasted cicadas, and today, the emergence of large broods spawns cook-offs among entomophagists.    

Part 3: PERIODICAL CICADAS ARE AROUND ALL THE TIME — WHAT’S THE BIG DEAL ABOUT 2024?

Billions of cicadas, that’s what!  Enough cicadas to stretch to the moon and back 33 times – more than 15 million miles of cicadas, nose to tail.  As many as 1.5 million cicadas per acre, with 20 to 25 exit holes in a square foot of soil.  The simultaneous appearance over a 16 state area of two geographically adjacent broods, Brood XIII (the Northern Illinois Brood) and the periodical cicadas with the widest range, Brood XIX (the Great Southern Brood).  The simultaneous emergence of two broods – a 13-year species and a 17-year species – that last emerged together when Thomas Jefferson was president and that won’t appear together for another 221 years (by comparison, the next total solar eclipse will occur on August 12, 2026 – OK, 2044 if you insist on staying in North America https://en.wikipedia.org/wiki/List_of_solar_eclipses_in_the_21st_century).    

How far will Wisconsin eco tourists will have to travel?  Just to our southern border – scroll down for a map: https://www.smithsonianmag.com/smart-news/cicadas-are-coming-rare-dual-emergence-could-bring-one-trillion-of-the-bugs-this-year-180983635/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=editorial&spMailingID=49350631&spUserID=ODg4Mzc3MzY0MTUyS0&spJobID=2622459374&spReportId=MjYyMjQ1OTM3NAS2.

As always, the question is “Can you get high on Periodical cicadas (beyond the sheer joy of witnessing the exuberance of Nature, of course)?  Well —- maybe. 

About 5% of Magicicada nymphs may become infected with a fungus called Massospora (a so-called Zombie fungus) that produces both the psychedelic chemical psilocybin (think “magic mushrooms”) and an amphetamine/stimulant called cathinone.  The nymphs are exposed when they enter the soil after hatching, or while they’re living underground, or even as they tunnel up to emerge as adults.  When the adult matures, its butt falls off and is “replaced” by a white mass of fungal spores https://bugguide.net/node/view/1980876/bgimage – “what entomologists affectionately call ‘flying salt shakers of death,’” says the National Audubon Society website.  With the fungus calling the shots, behaviorally, infected adults initiate a lot of romantic encounters, and they often walk along the ground, dragging their nether portions and thereby depositing spores on the soil.

Part 4: CICADA MISCELLANIA

Cicadas aren’t known to carry diseases, but after a Brood XIII emergence in 2007, lots of suburban Chicagoans had nasty, itchy rashes.  Turns out that a tiny mite called the Oak gall mite (aka the “itch mite”) eats cicada eggs when it’s not eating Oak leaf gall midges.  More cicada eggs = more mites = more human-mite encounters. 

During the Brood X emergence a few years ago, a disease was seen in birds in the same geographical area.  It was suspected that there was a link to the cicadas that suddenly dominated their diet (biological magnification), but it was not determined whether the problem was the extra load of cicada “meat” itself, chemicals that the nymphs or adults may have been exposed to, or soil bacteria or fungi that came to the surface with the nymphs.  The disease eased as the cicadas died off.

History geeks please note the History section of the Wikipedia write-up on Periodical cicadas, documenting cicadas in the early years of our Republic: https://en.wikipedia.org/wiki/Periodical_cicadas.  

Learn to make an origami cicada at https://cicadasafari.org/download/foldacic2021.pdf.

And speaking of biological exuberance, our skies are suddenly filled with Red Admiral butterflies (and some Painted Ladies, too) migrating up from the South and Southwest.  Early butterflies don’t rely on flowers; they feed on sap dripping from trees.

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Bugs without Bios XIX

Bug o’the Week
by Kate Redmond

Bugs without Bios XIX

Howdy, BugFans,

Bugs without bios – those humble (but worthy) bugs about whom little information is readily available.  Today’s bugs check those boxes as species, but they have something in common – their lifestyles are similar to those of close relatives who have already starred in their own BOTW.

The BugLady found this PREDACEOUS DIVING BEETLE (Hydacticus aruspex) (probably) in shallow water that was so plant-choked that the beetle had trouble submerging.  Diving beetles are competent swimmers, tucking their two front pairs of legs close to their body and stroking with powerful back legs.  When they submerge, they carry a film of air with them to breathe, stored under the hard, outer wing covers (elytra).  They can fly, too, though they mostly take to the air at night.

As both larvae and adults, Predaceous diving beetles are aquatic and carnivorous, dining on fellow aquatic invertebrates.  Larvae (called water tigers) grab their meals with curved mouthparts and inject digestive juices that soften the innards, making them easy to sip out (generic water tiger – https://bugguide.net/node/view/49848/bgimage).  They eat lots of mosquito larvae.  Adults grab their prey and tear pieces off.  Not for the faint of heart.   

Hydacticus aruspex (no common name) is one of five genus members in North America and is found across the continent.  It comes in both a striped and a non-striped form https://bugguide.net/node/view/296320/bgimage.  It overwinters as an adult, under the ice, and romance blossoms in spring.  For more information about Predaceous diving beetles, see https://uwm.edu/field-station/bug-of-the-week/predaceous-diving-beetle-revisited/

These spectacular OBLIQUE-WINGED KATYDIDS (probably) were climbing around on Arrow Arum in a wetland that the BugLady frequents.  Katydids are famous singers whose ventriloquistic calls may be heard day and night (though older ears may strain to hear them – test your hearing here https://www.listeningtoinsects.com/oblong-winged-katydid).  They “sing” via “stridulation” – friction – in their case, by rubbing the rigid edge of one forewing against a comb-like “file” on the other (the soft, second set of wings is only for flying, and they do that well).  They hear with slit-like tympana on their front legs.  Most Katydids are vegetarians, but a few species are predaceous.

Oblong-winged Katydids (Amblycorypha oblongifolia) are “False katydids” (here’s a True katydid https://bugguide.net/node/view/2207342/bgimage) in the Round-headed katydid genus.  They are found in woods, shrubs, and edges throughout the eastern US, often in “damp-lands,” often on brambles, roses, and goldenrods.  The dark, mottled triangle on the top of the male’s thorax is called the “stridulatory field” – a rough area that is rubbed to produce sound.  Oblong-winged katydids have a large stridulatory field. 

Katydids, both in color and in texture, are remarkably camouflaged – except when they’re not.  Here’s an awesome color wheel of katydids https://entnemdept.ufl.edu/creatures/misc/amblycorypha_oblongifolia.htm

For more information about the large katydids (including the origin of their name), see https://uwm.edu/field-station/bug-of-the-week/katydid-rerun/.

The BugLady came across this cute little MOTH FLY (Clytocerus americanus) (probably) on a day that she couldn’t take an in-focus shot on a bet!  Fortunately, bugguide.net contributors did better https://bugguide.net/node/view/426325/bgimagehttps://bugguide.net/node/view/695589/bgimage.  Despite their name, Moth flies are moths, not flies or weird hybrids.  They are tiny (maybe 1/8”) and hairy, and are weak fliers, and until she saw this one, the only Moth flies she had ever seen were indoors, in the bathroom (where they earn another of their names – “drain flies”).  Species that live outside are, like this one was, often found near wetlands. 

There are only one or two species in the genus Clytocerus in North America, and they have strongly-patterned wings and very hairy antennae.  Not much is known about their habits.  According to Wikipedia, adult Clytocerus americanus feed on “fungal mycelia and various organisms which inhabit wet to moist environments. Larvae are assumed to be detritivores.”

Find out more about moth flies here https://uwm.edu/field-station/bug-of-the-week/moth-fly/

MASON WASP – This is what happens when the BugLady buys garden stakes!  After various small, solitary wasps populate the empty interiors with eggs, the BugLady can’t possibly stick them into the ground! 

As their name suggests, female Mason wasps use mud to construct chambers in preexisting holes to house both their eggs and the cache of small invertebrates that their their eventual larvae will eat. 

The Canadian Mason Wasp (Symmorphus canadensis) suspends an egg from the chamber roof or wall by a thread and then adds 20 or more moth or leaf mining beetle larvae before partitioning it off with a wall of mud and working on the next cell https://bugguide.net/node/view/509856/bgimage.  She leaves a “vestibule” at the end of the tunnel/plant stake between the final chamber and the door plug. 

Heather Holm, in her sensational Wasps: Their Biology, Diversity, and Role and Beneficial Insects and Pollinators of Native Plants, discusses the hunting strategy of genus members: “Symmorphus wasps hunt leaf beetle larvae (Chrysomela); these beetles have glands in their abdominal segments and thorax that emit pungent defensive compounds.  These compounds are derived from the plants that the larvae consume. ….. In addition to using visual cues to find their prey, it is likely that Symmorphus wasps use olfactory means to find the beetle larvae.  Symmorphus males have been observed lunging at Chrysomela larvae, mistaking the larvae for adult females [female mason wasps] that, after capturing and handling prey, smell of the offensive compounds.

Here are two previous BOTWs about mason wasps, each a different genus than the Canadian Mason wasp: https://uwm.edu/field-station/bug-of-the-week/bramble-mason-wasp/ and https://uwm.edu/field-station/bug-of-the-week/four-toothed-mason-wasp/.    

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – The Monarch Butterfly Problem

Bug o’the Week
by Kate Redmond

The Monarch Butterfly Problem

Howdy, BugFans,

The BugLady wrote this for an upcoming newsletter of the Lake Michigan Bird Observatory (an organization that would love your support).  It started out as a simple report about this year’s survey of overwintering Monarch Butterflies, but then it took the bit in its teeth and became oh-so-much more.  Put your feet up.

Every fall, most of the Monarch Butterflies east of the Rockies set their compass for a small patch of mountains just northwest of Mexico City.  This winter’s count of eastern Monarch Butterflies (Danaus plexippus plexippus) overwintering in the oyamel fir forests of central Mexico was the second lowest since annual censusing began in 1993.  In the 1990’s, the eastern Monarch Butterfly population was estimated at 70 million, and today’s numbers represent an 80% decline in population.

The census is not an actual nose-count of the butterflies themselves but is a measurement of the area they occupy.  They’re densely concentrated on their wintering grounds — scientists estimate between 20 and 30 million Monarchs per hectare (about 2.5 acres).  The lowest area, 0.67 hectares (1 66 acres), occurred 10 years ago, and the largest ever, in 1996-97, found 45 acres occupied.  This year, Monarchs were seen on 0.9 hectares (2.2 acres), down 59% from the 2022-2023 season (Dr. Karen Oberhauser, founder and director of the Monarch Larva Monitoring Project (https://mlmp.org/), points out that 2.2 acres is smaller than two football fields).  It’s felt that almost 15 acres of overwintering butterflies are needed to maintain a healthy eastern population.  “Monarch populations [are] at a level that most scientists suggest is not sustainable,” says Dr. Oberhauser.  Western Monarchs, residents and migrants along the Pacific Coast, are treated as a separate population.   

Migration is expensive, energy-wise, and is dangerous, and the list of hazards is long.  Land use changes and habitat loss, herbicides and pesticides, loss of milkweed, car-butterfly collisions, climate change that brings harsh winter conditions to central Mexico or storms as the butterflies prepare to depart, or that puts migrating butterflies out of sync with nectar plants on their spring migration, high temperatures that reduce the nutritional value of milkweed plants, and severe drought along the fall migration route through “the Texas Funnel” have all been suggested as factors.

The integrity of the fir forests themselves is critical, but the illegal logging that has reduced the forest size and cover in the past was held to a minimum last year.  The butterflies depend on a dense forest to act as insulation so they don’t have to expend as much energy staying warm, dry, and hydrated. 

Quick review of Monarch biology and migration — there are four or five generations annually, and the last brood of the year is extraordinarily long-lived for a butterfly.  It emerges in August or September, and while the earlier generations are reproductively active, this final generation is not.  Signaled by decreasing day length, lowering angle of the sun, cool nights, and increasingly leathery milkweed leaves, their reproductive organs don’t mature.  Instead, they apply their energy to a journey – a leisurely trip that can cover more than two thousand miles and take two months.  The butterflies feed on nectar from a wide variety of flowers as they wend their way south, and while a newly-emerged Monarch in Wisconsin has about 20 mg of fat in its body, a Monarch newly-arrived in the oyamel fir forests of Mexico may carry 125 mg of fat.  They eat little on their wintering grounds. 

With the warming temperatures of late March, they become reproductively ready and head north through northern Mexico and our Southern states, laying eggs as they go, careful not to get ahead of the emerging milkweed plants.  Their young — the first-generation offspring of the Mexican butterflies — keep moving and recolonize the north, often arriving in Wisconsin in mid-May and in Canada shortly after that (Southern summers are too hot for the caterpillars to thrive).

Their offspring – the second generation out of Mexico, continue to lay eggs and may fly a little farther north, but most have reached their destinations by the end of June.  The “job” of this short-lived generation (and of the next generation, if there’s time for one) is to stay put and use their energy to build up the population.  The migratory final generation, sometimes called Gen 5 or the Super Generation, is the only one that is tagged. 

This complicated dance depends on good weather, milkweeds for caterpillars, and abundant nectar plants for adults.  Monarchs will lay their eggs on a variety of milkweed species, but Common milkweed is the favorite. 

Follow the northward wave of Monarchs here https://maps.journeynorth.org/map/?map=monarch-adult-first&year=2024.

There have been passionate efforts in past years to list the Monarch as an Endangered Species under the Endangered Species Act (ESA).  Classification under the ESA is a lengthy process, there are many other deserving candidates, and listing requires both a recovery plan and a dedicated budget https://uwm.edu/field-station/bug-of-the-week/listing-the-monarch/.   

Monarch populations are subject to wide swings, but a low year followed by another low year lessens the possibility of a speedy comeback.  Overall population levels in the summer of 2023 were not alarming, but severe heat and drought in the Texas Funnel migratory corridor probably resulted in fewer Monarchs finishing their journey to Mexico. 

Based on a few recent studies, there are voices, even voices within the Monarch Butterfly community, that suggest (counterintuitively) that there’s no need to change the Monarch’s status, citing past population plunges and recoveries.  The International Union for Conservation of Nature (IUCN), a leading scientific authority on the status of species, recently downgraded Monarchs on their Red List of Threatened Species from Endangered to Vulnerable. 

Some of the arguments are historical.  Monarchs like milkweeds, and milkweeds like sunshine, and the treeless Great Plains is thought by some to be the historical center of both Monarch and milkweed populations.  Too, there was lots of sunshine during the long postglacial period while trees moved back north after the most recent glacier pushed them south, and some speculate that milkweeds and Monarchs took that opportunity to push east and increase their numbers before the forests regrew. 

The early settlers cut down swathes of America’s Great Eastern Forest to establish villages and farms, making the area sunnier and more Monarch/milkweed-friendly, and some say that Monarch populations are larger now than they were 200 years ago.  Today, they say, Monarchs are adapting to modern stressors, and they’re establishing some non-migratory breeding communities in Florida and around the Gulf Coast.  Monarchs, some scientists say, are not at risk, but the eastern Monarch migration may be (a distinction without a difference to Monarch lovers).   

Did the Monarch’s eastward expansion into a glacially-modified landscape and later into a human-modified landscape artificially boost their numbers, so that what’s happening today is just a “course correction?”  Should we base the butterfly’s status on the wintering numbers rather than the summertime population?  On today’s numbers vs long-time averages?  Is it better to err on the side of caution?”  Will there, as Chip Taylor of Monarch Watch says “always be Monarchs?”

Only time –- and more research — will tell who’s got it right.  In the meantime, what can we do to help? 

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Tobacco Budworm

Bug o’the Week
by Kate Redmond

Tobacco Budworm

Greetings, BugFans,

The BugLady photographed this handsome moth on her back porch rail last summer, and she was temporarily mystified when she identified it as a Tobacco budworm moth, because the nearest tobacco farm is probably more than 100 miles west of her.  Then she found an alternative common name – the Geranium budworm – and since she is the Geranium Queen, it made more sense (and it explained the frass on the bookshelves).

There are lots of moths that aren’t big enough or bad enough or beautiful enough to have been studied enough.  This isn’t one of them.  It gets University Extension Agents riled up throughout tobacco and cotton-growing areas in the southern half of its range.

Tobacco budworms (Chloridea virescens) (before 2013 they were Heliothis virescens) are native moths in the Owlet moth family Noctuidae.  They’re considered an eastern and southwestern species, but they’ve been spotted in Canada, across the vast majority of the lower 48 plus the Caribbean, and sporadically south of the Rio Grande.  They produce five or six broods annually in the South, but generally just one or two in the North, and they are too tender to overwinter here.  Moths seen in the northern parts of the US in the second half of summer may have overwintered in a greenhouse or a sheltered patio or in a potted plant that was brought inside in fall, or they may have drifted north from the southern part of their range. 

Adults have a wingspread of about one-to one-and-a-half inches and are somewhat variable in color.  Virescens means “being or becoming green” and while some are greenish https://bugguide.net/node/view/662023/bgimage, many Tobacco budworm moths are tan https://bugguide.net/node/view/1440535/bgimage.  The caterpillars’ color is also variable and, as David Wagner says in Caterpillars of Eastern North America, “Somehow the larvae end up matching the color of their foodplant.  The caterpillars found on red geraniums are shades of pink, those on ground cherry yellow, and so on.”  https://bugguide.net/node/view/1735907/bgimage (pink flowers make pink frass https://bugguide.net/node/view/32268/bgimage), https://bugguide.net/node/view/899588/bgimagehttps://bugguide.net/node/view/36749/bgimage.   

The first generation of larvae chew deeply into buds (scroll down https://extension.umn.edu/yard-and-garden-insects/tobacco-budworms) and the later broods feed on the flowers and seeds.  They prefer the reproductive tissues, but they’ll also eat leaves, leaf petioles and even stems, and the later generations cause the most damage to plants.  No picky eaters here – these are generalist feeders!  They especially like tobacco and cotton, but they eat other agricultural crops like soybeans, flax, squash, tomato, peanuts, peppers, lettuce, and alfalfa and other clovers,.  Garden flowers like roses, geraniums, morning glory, petunias, nicotiana, chrysanthemums, marigolds, snapdragons, zinnias, and verbenas are on the menu, and, as the bulletins say, so are “weeds” like beardtongue, cranesbill/wild geranium, dock, lupine, passion flower, ground cherry, and more (“weeds” – so judgy).  They’re not considered a pest here in God’s Country.     

They are eaten by a variety of insects and spiders, but where some of their predators are concerned, the caterpillars seem to have Super Powers.  According to Wikipedia, if a parasitic wasp named Cardiochiles nigripes approaches a caterpillar with the intention of laying an egg on it, a fluid oozes from the caterpillar’s pores “that causes C. nigriceps to become agitated and groom themselves, allowing the budworm to escape. C. nigriceps also avoid budworms painted with this exudate. It is hypothesized that this exudate may function by overloading the wasp’s sensory receptors.”  The tachinid fly Winthemia rufopicta may be successful at laying eggs on the exterior of a tobacco budworm caterpillar, “but upon hatching and trying to penetrate its host, the caterpillars react by biting, crushing, puncturing, or trying to eat the parasitoid eggs.  This kills off many of the maggots” (Wikipedia).  Plus (says Wagner) “My colleague Scott Smedley and his students recently discovered that the caterpillars manage to transfer the glandular defensive secretions of their foodplants onto their own setae [hairs], and in doing so accrue chemical protection from ants and other natural enemies.”

They court with pheromones – she releases chemicals (perfumes) into the air, but she will not produce them unless she has been in contact with a potential host plant, and a place to lay her eggs is assured.  He reads her signals with receptors on his antennae and responds, and when she picks up his signal, she stops producing hers.  Males court with pheromones produced by glands in structures called hair pencils, which pop out of their abdomen.  The chemicals he produces are “twofers” – they send a “back-off” message to other males, and a “come hither” message to females.  If she approves of his scent, it’s “game on.”  The odor has both a stimulating and tranquilizing effect on her. 

She lays her eggs https://bugguide.net/node/view/699644/bgimage (usually 300 to 500 of them, but as many as 1,500) on buds, blossoms and leaves in the upper parts of plants.  Research suggests that she picks as a host the same species of plant that she grew up on.  The larvae hatch and, if they’re not already there, head for the tips of the plant.  Larvae grow faster at warmer temperatures, and when they are mature, they pupate a few inches under the soil https://bugguide.net/node/view/587565/bgimage

Two big photo references – one to Wisconsin moths https://www.butterflyidentification.org/moths-by-state-listing.php?reach=Wisconsin, and the other a giant collection of caterpillar pictures by wildlife photographer Tom Murray (Wisconsin shares many moth species with New York) https://pbase.com/tmurray74/moth_caterpillars.

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Cylapus tenuicornis Plant Bug

Bug o’the Week
by Kate Redmond

Cylapus tenuicornis Plant Bug

Howdy, BugFans,

One day last August, the BugLady pulled her mail out of her mailbox and saw this little bug sitting on a newspaper, and she managed to take a few shots of it with her purse camera before it departed.  She had never seen it before, but its gestalt reminded her of the (unrelated) Japanese barklice https://bugguide.net/node/view/296617/bgimage that she once encountered in southern Ohio, and of the (related) Clouded plant bugs she’s photographed locally https://bugguide.net/node/view/950344.  If BOTW had an “Obscure (but Cute) Insects” category (and many BugFans might argue that it already does), this bug would be right at home there.

When she is researching these anonymous insects, the BugLady starts with the species, and if information is thin on the ground, she backs up to genus, and then maybe backs up even farther, to tribe or subfamily or family.  And so it was for Cylapus tenuicornis (no common name).

So – from the top – moving from the most general to the most specific classification:

Cylapus tenuicornis is in the True Bug order Hemiptera (110,000 species known worldwide out of an estimated total of 200,000, with 2,000 in North America).  Hemipterans have piercing-sucking mouthparts that most apply to plants, but there are some carnivores and blood suckers in the bunch.  

It’s in the large and diverse Plant bug/Leaf bug/Grass bug/Jumping tree bug family Miridae (11,000 known species with many more awaiting names and descriptions).  Most Mirids are small (under ½”), soft-bodied, and inconspicuous, except when they are being pests of agricultural crops.  Most are plant feeders – some are generalist feeders, and some target specific plants.  Females use their sharp ovipositor to cut slits in plants and deposit eggs.   

According to the Plant Bug Planetary Biodiversity Inventory at the University of New South Wales (the BugLady sometimes goes far afield for information), “Many lineages are strongly myrmecomorphic [ant-shaped] although the nature of their associations with ants are still not well understood.” https://bugguide.net/node/view/1047082/bgimagehttps://bugguide.net/node/view/1299663/bgimagehttps://bugguide.net/node/view/15814/bgimage.    

Another step down – they’re in the largely subtropical/tropical subfamily Cylapinae (500 species), which researchers seem to agree is an understudied group that’s probably due for some taxonomic wrangling.  Cylapines are hard to study (or even to collect) because they mostly live in leaf litter and in bark crevices and are hard to spot and pretty speedy.  Cool thing about the Cylapinae is the fact that “Bugs in this group tend to forage actively on fungus covered rotten logs in humid tropical forests.” (Wikipedia).  More about that in a sec.  

And down another step – there are 12 species in the genus Cylapus, but only one lives in North America.  It’s a Neotropical genus (found in the New World tropics, from Central America and the Caribbean, south).  They are diurnal (out and about in the daytime).  

Whew!  Finally! 

Cylapus tenuicornis is at home in eastern North America https://bugguide.net/node/view/40769/data.  They’re about a fourth of an inch long, “bug-eyed,” with long antennae.  Here’s what they look like when they’re not sitting on the Ozaukee Press: https://www.marylandbiodiversity.com/view/19791

One question that the BugLady always asks about her subjects is “What do they eat?”  And for this, we have to go back up to the subfamily.  Among the people who study the Cylapinae there’s a fair amount of discussion about their menu.  Remember – these bugs are typically seen on/under bark/leaf litter and on rotting logs in association with fungi.  There’s been speculation that some are predators (though long legs and antennae aren’t good adaptations for chasing prey under tree bark), but a subfamily member with the awesome name of Fulvius imbecilis has been reported as preying on the larvae of small beetles and flies and assorted other invertebrates that they find under bark and in certain fungi.

But there has long been a suspicion that some species feed on specific fungi, an unusual preference among the Hemiptera.  In lab experiments, Cylapus tenuicornis probed in the crevices of the fungi and underlying bark, and nymphs of two South American species mature within fungi.  Some Cylapinae were eventually seen eating fungi, but researchers investigated to make sure that the bugs were eating fungi rather than eating bugs that were eating fungi.  In this case, “investigate” meant catching some of them (no mean trick) and dissecting them to see if they had fungal materials in their guts.  Some did, and in amounts that indicate direct feeding.  

Lots of mysteries out there!  YAY!

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Burrowing Wolf Spider

Bug o’the Week
by Kate Redmond

Burrowing Wolf Spider

Greetings, BugFans,

One afternoon in late June as the BugLady was walking along the cordwalk at Kohler-Andrae State Park, she noticed a few half-inch-ish holes in the sand, holes that had more “structure” than the ones she makes with her walking stick, and larger than those made by solitary wasps.  She took a couple of throwaway shots and was very surprised when she put one up on the monitor and noticed eyes and legs!  She photographed more holes on subsequent trips, but their openings were unoccupied.  The cordwalk goes over both dunes with loose sand, and areas with low vegetation and a somewhat more organic soil.  The holes were in the loose sand.

She asked BugFan Mike if it might be a wolf spider called the Burrowing Wolf Spider (Geolycosa missouriensis).  He said that was a possibility and urged her (as always) to be conservative in her spider IDs, especially considering the quality of the picture.  Amen, Mike!

Wolf spiders (family Lycosidae) (lycosa is Greek for “wolf”) are common, hairy, nocturnal, ground-dwelling hunters with very good eyesight.  Most species of wolf spider do not spin trap webs. 

[Quick Detour: nowadays, we use the name “tarantula” to refer to a group of non-Lycosid, palm-sized, hairy, tropical spiders https://bugguide.net/node/view/289856/bgimage.  The BugLady’s 4th grade teacher told a story of being in basic training in California and digging foxholes that bisected tarantula borrows, which she thought was pretty cool (she doesn’t remember much else of 4th grade).  Anyway, the original tarantula is a southern European/Italian wolf spider.  Legend had it that if one bites you, you‘re doomed to dance a dance called the tarantella.  The BugLady assumes that when they saw the big hairy spiders, those settlers from the Old Country applied the name of a scary spider that they already knew about.  And in fact, a number of other groups of large spiders have been called tarantulas, too].

Wolf spiders in the genus Geolycosa are called the Burrowing wolf spiders (geo means “earth”).  They live in vertical burrows, and they are habitat specialists, preferring loose, sandy soil that makes digging easier.  Of the 75 species in the genus worldwide, 18 live in North America north of the Rio Grande.  They have strong legs and (short spider anatomy review, here) two strong chelicerae (jaws) that are used as pincers and that are tipped with fangs.  A pair of palps, which look like a short leg on each side of the chelicerae, are used to manipulate food https://keys.lucidcentral.org/keys/mites/ismite/html/a10h_Mouthparts.html

Burrowing wolf spiders are generally Stay-at-Homes – the spiderlings don’t scatter far from the maternal burrow.  They initiate their own lair when they’re very small, enlarging it as they grow, rarely straying more than an inch or so away from it, and retreating into it when alarmed.  Populations remain fairly restricted. 

They are tied to one spot, with fixed pools of prey and of potential mates, but the trade-off is an absence of Flying Monkeys. They can dodge predators and avoid desiccation within a relatively stable, climate-controlled tunnel.  In early fall, though, when a young spider’s fancy turn to love, he abandons that security and sets off in search of romance.  They mate in late summer, but the gravid female doesn’t make an egg sac until the next spring.  She displays maternal care – carrying around first her egg sac, and later her young https://bugguide.net/node/view/114423/bgimage (and not eating them).  Spiderlings hatch in early summer, overwinter as immature spiders in their first year, and become adults in late summer of their second year.

Gratuitous vocabulary word(s) of the day: some Geolycosa species are “turricolous” (they live in areas that have some leaf litter, and they create little turrets or lips made of debris, sand, and silk around the opening of the tunnel https://bugguide.net/node/view/912651/bgimage), and others are “aturricolous” (they don’t). 

Bracing itself within the tunnel with its legs, the spider uses its fangs to loosen the sand, and if the sand is not moist enough on its own, it uses silk to compact the sand into a pellet.  It uses its chelicerae and palps to move the pellet to the opening of the burrow, and it disposes of the pellet by flicking it away (sometimes a foot away) with its forelegs – unless it’s going to use it to build a turret.  Burrowing wolf spiders reinforce the upper section of their lair by covering the walls with a few layers of silk.  Summer burrows are less than a foot long, but winter burrows may be more than five feet deep.  Researchers who studied Geolycosa missouriensis noted that a spider excavating an average burrow removed 918 sand pellets. 

Larry Weber, in Spiders of the North Woods, says that if you stick a grass stem down an occupied Geolycosa missouriensis burrow, the spider will grab it and hang on, and you can dig out the entrance and see the spider.  Seriously, Larry?  All that work – 918 pellets – why would you?

They ambush their prey – lurking in the entryway and darting out to grab nocturnal invertebrates like crickets as they wander by.  They feed within, and the indigestible bits of prey fall to the end of the tunnel.  About the Geolycosa, the publication “The Insects and Arachnids of Canada, Part 17,” notes that when kept in captivity, “They should be individually caged because they are fierce predators, and cannibalism can soon reduce the culture to a single well-fed individual.”

So – who was in that burrow?  Here are a few possibilities.

A BURROWING WOLF SPIDER (Geolycosa missouriensis), aka the Missouri Earth Spider or the Missouri Wolf Spider, is found on sandy loam soils from Texas to Ontario and Saskatchewan https://bugguide.net/node/view/862935/bgimage.  Its leg-spread is around 1 ½”. 

The gravid female uses sand and silk to fashion a door for the tunnel in winter.  She will bring her egg case into the sun at the burrow opening on warm, spring days, and females can be found in their burrows carrying young on their back in early summer.  Sources are ambivalent about whether Geolycosa missouriensis makes turrets.  

GEOLYCOSA WRIGHTII (no common name) https://bugguide.net/node/view/1285635/bgimage.  It’s not as common, and its range is restricted to sand dunes and beaches from Indiana and Illinois north through the Western Great Lakes states and provinces.  Females protect their newly-hatched offspring by sealing themselves into the tunnel with their young for a few days, until they find their feet.  Geolycosa wrightii doesn’t make a turret. 

The BEACH WOLF SPIDER (Arctosa littoralis https://bugguide.net/node/view/771440/bgimage) also makes silk-lined tunnels, but unlike the Geolycosa, it hunts at night by chasing after prey on beaches and wetland banks, and shelters in tunnels or under driftwood in the day.  Entomologist Eric Eaton says that if you’re abroad on the beach at night, wearing a headlamp, “When the beam of the light hits a wolf spider, the animal’s eyes will glint a blueish-green shine…..and a female with young on her back looks like a diamond-studded stone.” 

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Become a Member

Take advantage of all the benefits of a Riveredge membership year round!

Learn More