We’re getting a jump on National Pollinator Week (June 17 to 23) with a few articles about pollinators, which, if you like to eat or watch birds or photograph flowers or (add your favorites here ___________) are pretty indispensable.
What does it take to be a successful pollinator? The ability to deliver pollen to multiple flowers in a short time span and the ability to transport pollen, either by general hairiness or by special pollen carrying structures. Ants, with their smooth exteriors, impeccable grooming, and pedestrian habits, are all over flowers, but they are inefficient pollinators.
A lot has been written in the past decade about the crash of honey bee colonies. Honey bees are, after all, responsible for pollinating about one-third of the foods we eat, accounting for about $15 billion in crop values annually (and they make honey and beeswax, too). But, honeybees are an alien bee that was imported to pollinate alien crops, and we have many species of native bees. Do honey bees disrupt native relationships – https://www.nature.com/articles/s41598-019-41271-5?fbclid=IwAR3gFJuCvy1t3GEPCRGDW1nDzOGLjB-G0vLFiYHJtfU7TgVLTUnShMa5NJ0
YAY, it’s June! That means that the BugLady is out on the trails, walking slowly, looking at everything and photographing half of it. A probably-tasteful BOTW will be delivered to your inbox each Tuesday in June, but it won’t be a newly-minted, original episode.
It’s also June – National Invasive Species Action Month! “Alien,” “Introduced,” “Exotic,” and “Non-native” are all words we use to describe species that aren’t from around here, like alfalfa and Golden retrievers, but those words are not synonymous with the word Invasive. Having left their predators in the Old Country, invasive species achieve populations that negatively affect their habitat and native species. Not all invasive species are from another continent – Rusty crayfish, invasive in Wisconsin, hail from the southeastern part of the country.
And a picture of a really beautiful little beetle that arrived in the Detroit area from China about 20 years ago and that has changed the landscape here in Wisconsin and in much of North America east of the Great Plains – the Emerald ash borer (EAB) https://uwm.edu/field-station/bug-of-the-week/emerald-ash-borer-redux-family-buprestidae/. When it first appeared, the DNR predicted that it would demolish 99.9% of Wisconsin’s ash trees. Their flight period is about to start.
And a Deer tick.
Not all invasive species are insects – see the Southeast Wisconsin Invasive Species Consortium (SEWISC) for information about invasives near you www.sewisc.org (they’d love a donation, too).
We’re wrapping up National Wetlands Week with a beetle that you don’t even need a magnifying glass to see! This is a revision of an episode that first aired in the summer of 2009 – new words; no new pictures.
BOTW hasn’t plunged underwater for several months now, but in this episode we will get a chance to get our collective gills wet again. Water scavenger beetles are hefty beetles (some measure more than 1 ½ inches) in the family Hydrophilidae that are easily mistaken for Predaceous Diving beetles (family Dytiscidae https://bugguide.net/node/view/1415131/bgimage) of previous BOTW fame (https://uwm.edu/field-station/bug-of-the-week/predaceous-diving-beetle/). Other than sharing their classification in the beetle Order Coleoptera, they are not closely related. North America hosts more than 250 species of Water scavenger beetles, including an introduced, non-aquatic species that makes itself at home in dung, where its larvae eat maggots (fly larvae).
Along with their beetle classification, they also share with Predaceous diving beetles the shallow waters of freshwater ponds and quiet stream edges, although Water scavenger beetles like their weedy, algae-choked habitat a bit warmer than Predaceous diving beetles do. What they do not share is a lifestyle. Adult Water scavenger beetles (depending on species) may feed on their aquatic neighbors or may be recyclers, with a food pyramid that includes algae and, as their name suggests, decaying vegetation and dead animal tissue.
The very-carnivorous Water scavenger beetle larvae (https://bugguide.net/node/view/1872987/bgimage) are described as “sluggish” and are found crawling on the pond floor or climbing on underwater vegetation. The larvae are couch-potato versions of the sleek Predaceous diving beetle larvae/water tigers (https://bugguide.net/node/view/2276347/bgimage), though they sometimes share the same “water tiger” moniker. Their feeding category is “engulfer-predator” – they use their powerful, hollow jaws https://bugguide.net/node/view/183298/bgimage to subdue and then vacuum out the juices of their prey. Their food-list includes their brethren, along with other aquatic invertebrates (they love mosquito larvae) and they also go after tadpoles, snails, and mini-fish.
According to Eaton and Kaufman, in the Field Guide to Insects of North America, some species of Water scavenger beetles can squeak by rubbing their abdomen against the underside of their wing covers. Wikipedia lists a repertoire of “stress calls, a male courtship call, a male copulating sound, and a female rejection buzz.”
Water scavenger beetles overwinter as adults, and in early summer, females lay eggs in a cocoon-like structure that’s attached to aquatic plants or left to float like a raft. In The New Field Book of Freshwater Life, Elsie Klots says that the egg case of one genus includes a vertical “mast” that extends above the water’s surface. The mast may be involved with respiration, but it may also be an escape hatch for larvae – escape being vital in a group whose young hatch from eggs within a case and immediately start chowing-down on their siblings. A case may hold 100+ eggs at the start, but cannibalism reduces the number of larvae that live to exit.
They spend a month underwater as larvae and then leave the water and create a pupal cell by scooping away soil with their mandibles. It takes them 36 to 48 hours to dig a hole that’s three inches deep. They climb in and pupate, reappearing as adults in a few weeks.
Predaceous diving beetles breathe, as many aquatic insects do (and as Water scavenger beetle larvae do), by backing their rear end up to the water’s surface and taking in air with a tube or pore (some Water scavenger beetle larvae also have exterior, branched gills https://bugguide.net/node/view/1058195/bgimage). Adult Water scavenger beetles break through the surface film with un-wet-able (“hydrophobic”) antennae that form a funnel through which air is transported. Oxygen is stored in a space under the elytra (hard wing covers), and the beetle takes that air into its body through its spiracles (breathing pores). The nickname “silver-beetle” is a nod to its secondary source of oxygen – a film of air bubbles that typically covers the beetle’s flat ventral surface, trapped there in a layer of thick hairs. Air held in these hairs can be renewed from oxygen suspended in the water, allowing the beetle to stay under longer.
It seems that Water scavenger beetles have a Super Power – at least, one Australian species does! It’s the ability to locomote on the underside of the surface film (remember – due to electrical charges, the layer of water molecules at the surface of a body of water is “tougher” than the molecules below it, which is what allows some insects to skate along its surface. This same surface tension makes it hard for small critters to break through from below). See the video here https://www.smithsonianmag.com/smart-news/beetle-can-walk-along-underside-waters-surface-180978115/. Snails and leeches can do this, too.
The air trapped on the underside of its body may help the beetle stay “belly-up” without using extra energy, giving it enough buoyancy to stroll along under the surface film without breaking through, though each footstep makes the water dimple upwards (scientists don’t know exactly how the beetle’s feet get traction). Researcher John Gould recounted seeing the phenomenon for the first time, “The beetle was casually walking along the underside of the water’s surface with ease while upside down. Every now and then, it would come to a stop, and then kept plodding along across the surface as if it was walking across any regular solid.”
How does the beetle do this? Why? Are there other beetles that do it? Scientists who collect aquatic beetles report that when they roil up the substrate with their nets, beetles often float up to the surface. But do they walk around up/under there, or do they return to their normal haunts ASAP? So many questions – stay tuned.
WATER SCAVENGER BEETLE MISCELLANIA:
J. Reese Voshell, Jr, in A Guide to Common Freshwater Invertebrates of North America, says that “beetle” comes from the Old English “bitula” – “to bite” – a reference to the strong jaws of adult beetles.
Shelly Cox, in her blog called “MOBUGS – Missouri’s Majority,” shares a great (but unattributed) quote about Water scavenger beetles – “This is a water beetle. It is the hardest object in the world to pick up with tweezers. The second hardest is Mount Everest.” The BugLady can’t speak to either of those.
Once upon a time, a Naturalist named Linda Bower wondered what she would see if she put a camcorder in a pond. A whole lot, as it turned out. She has expanded her gaze to include terrestrial bugs and non-insects, as you will see if you check the excellent offerings at https://www.youtube.com/channel/UCJ2iEp9598fAgiqdMwMZX_g. Glimpses of a world that exists under our radar. For the Aquatic playlist click on “Life in and Around the Pond.”
And remember – Every Month is Wetlands Month (and every fifth living thing is a beetle)!
We continue to celebrate Wetlands month with this slightly updated tale about ostracods, which originally aired in 2015.
By now it’s no secret that the BugLady is enthralled by wee aquatic critters, especially those that inhabit the waters of ephemeral ponds. Who needs charismatic megafauna! (and reminder – the BOTW definition of “bug” borrows more from that of a first grader than that of an entomologist).
Little bug – big story – put your feet up.
Once upon a time, there were ostracods. How do we know that? Because these tiny, aquatic critters, critters that you would never expect to contribute significantly to the fossil record, have, in fact, managed to produce the most numerous fossils of all arthropods. Ofallarthropods! That’s insects, spiders, centipedes, millipedes, and crustaceans. Since the Ordovician period, 485 to 443 million years ago. They’ve even been found in amber (fossilized tree sap), where they may have landed during a flood. So pervasive are they that a system has been developed for evaluating ancient climates (paleotemperatures) called the mutual ostracod temperature range (MOTR), based on a measurement of the building blocks in the ostracod’s shell. And, since the shapes of ostracod shells are indicators of their ecological milieu and of their feeding habits, they are used as paleoenvironmental indicators. And, fossilized ostracods are used to date marine sediments.
In the etymology department, Wikipedia tells us that the Greek root “ostracon” means “shell” or “tile,” and that “the word ‘ostracize’ comes from the same root, due to the practice of voting with shells or potsherds.”
Ostracods’ most recent family tree seems to read: Phylum Arthropoda (“jointed appendages”) (yes – they have appendages), subphylum Crustacea, and class Ostracoda. The Monterey Bay Aquarium website explains that because they look like a shrimp inside a seed pod, they are commonly called seed shrimp (and an older European nickname is mussel shrimp), but the BugLady thinks they look like swimming pistachios (OK – like what pistachios would look like if they swam). Fellow Crustaceans include the familiar pill bugs, crabs, crayfish, shrimp, and lobsters, as well as barnacles, fairy shrimp, and minute aquatic forms like daphnia, and copepods.
Ostracods are found worldwide, and there are lots of ostracod species, both marine and non-marine, with many more waiting to be discovered. The BugLady found estimates of 8,000 to 13,000 total living species, 2,000 of which are non-marine (non-salt water), with 420 of those non-marine species being found in North America. As many as 50,000 additional species have been identified from fossils. About half of the non-marine species are in the family Cyprididae, and the BugLady suspects that the ostracods she photographed belong in that family because the Cyprididae are noted for their ability to swim and to tolerate stagnant, oxygen-poor waters, and for having drought-resistant eggs, larvae and adults – important adaptations for an ephemeral pond dweller. There is a World Ostracod Database.
If you can think of an aquatic habitat – running water, still, permanent, ephemeral, underground, surface, salt, fresh, hot sulfur, brackish, shallow, or ocean abyss – there are ostracods living in it. They also occupy marginally wet habitats like mud and sand, algal mats, clumps of wet moss, and damp tropical soils. One species hangs onto the underside of the surface film in open water. Freshwater species probably evolved from ostracods that lived in brackish waters that flooded frequently, so that they gradually adjusted to lower saline levels. One source speculated that the biggest jump in new species of ostracods may come when groundwater is analyzed for their presence (the BugLady hasn’t seen any in her tap/well water, but maybe that’s why faucets have those little screen in them)!
Many species are generalists, not limited to a single habitat, and while most freshwater species are “benthic” (creeping about on the substrate/debris at the bottom of the body of water), some are active swimmers, others live on aquatic plants, and a few species are planktonic – moving passively with the water currents. In general, ostracods prefer the shallow water at the wetland’s edge, up to a depth of about three feet, and they are more active in light than in shadows. They can tolerate a wide range of water chemistries and temperatures, but they aren’t found in highly polluted waters.
In her Field Book of Ponds and Streams, Ann Haven Morgan calls ostracods “another army of minute crustaceans averaging only a millimeter in length, and impossible to tell apart with a simple lens.” What they have in common is two limy/calcified shells called valves, which are hinged at the back and held together with muscles like a scallop’s. This makes them look like teeny clams – teeny, hairy clams, because the outside of the valves may be covered with hair-like setae.
There’s a lot going on inside that shell – the body is somewhat flattened and is not segmented. The head end has two pairs of antenna-like appendages plus two pairs of mouthparts (mandibles and maxillae). Depending on the species, those all-purpose antennae, especially the second pair, may be used for digging, climbing, locomotion, and feeding, and males use them to clasp females. The thorax area has three pairs of legs that are variously used for locomotion, respiration and grooming. The rear end has two long “tails” called caudal or furcalrami that can also be used for locomotion. The appendages can be tucked inside the valves and the valves pulled shut if the creature is alarmed.
Ostracods come in a variety of colors from dark gray to yellow to red to blotched, and species living on green plants are often gray, green or brown. Most freshwater forms measure between 1mm and 3mm (1/8”), but one South American freshwater species is about a half-inch long, and some marine species are giants at almost 1 ¼” (“as big as a meatball,” says one source).
Scientists tell us that when they collect ostracods, most of the individuals they find are female. The number of males in a population depends on an ostracod’s species, and the type of reproduction is determined by the number of males in the population. Reproduction by parthenogenesis (virgin birth) is common, especially in freshwater ostracods (in some species, males have never been found), but in species with more males, sexual reproduction is de rigueur. Eggs are laid on rocks and vegetation or simply loosed into the water. The eggs hatch into active Nauplius larvae (named after Poseidon’s son) that have appendages on their head for swimming and that shed eight times on their way to adulthood. Eggs that are left in the mud when an ephemeral pond dries up will hatch when water returns, no matter how long it takes.
A diverse crowd like the ostracods shows up on many rungs of the trophic ladder. There are carnivores/predators, herbivores, detritivores, and scavengers but ostracods are generally characterized as omnivorous scavengers. They eat tiny organisms like algae, diatoms, bacteria, mold, and pieces of organic detritus that are present in the water or on vegetation. Some deliver food to their mouthparts via a current set up by the appendages. The BugLady found a picture of an ostracod straddling an aquatic leaf, rasping off food on both sides as it moved along the edge of the leaf. Ostracods are eaten by hydra and other benthic organisms and by small fish, larval salamanders, and waterfowl. One species has been shown to be able to survive a trip through a bluegill’s digestive tract.
Whether swimming or creeping, ostracods locomote by extending their appendages from between the valves, with the valves “ajar” https://www.youtube.com/watch?v=F32fyIeVBAM. Their main sense is touch – they move their antennae constantly and also have sensory hairs on their bodies. A Nauplius larva has a simple eye, as do the adults of some species.
The Ward Science supply company will sell you some ostracods, but they urge consumer responsibility: “Never purchase living specimens without having a disposition strategy in place,” they say, later adding that “In order to protect our environment, do not release any of these organisms into the wild. When you are done with the crustaceans, add bleach to the culture and dump it down the drain.” Good on you, Ward Science Supply. Hope everyone is listening.
Several species of marine ostracods have bioluminescence in their bag of tricks (they use luciferin and luciferase, the same two chemicals that lightning beetles use), and they glow blue at night in the water and on the sand https://oceanwire.wordpress.com/tag/ostracod-crustaceans/. The light is in a secretion that the ostracod releases when it is disturbed, and some species use it, like fireflies, to attract mates. The Japanese call them sea fireflies (umi-hotaru), and the BugLady came across an anecdote about how Japanese sailors during WWII read their instruments and charts by the light of bowls of luminescent ostracods, because regular light sources would have revealed their presence to the enemy.
Wetlands Month II Common Water lily Planthopper revised
Salutations BugFans,
Week 2 of National Wetlands Month features an upgrade of an episode that first appeared in March of 2014.
Water lilies are important plants in aquatic ecosystems. At the very least, they provide a dry spot for insects (and frogs and others) to perch on – at most, they are hearth and home. Various parts of the plants are eaten by organisms ranging from snails to moose, and the broad leaves modify/shade/cool the aquatic habitat below (the BugLady was tickled to see a few fish hiding under a lily leaf on a very hot day).
A water lily’s leaf and flower stay on the water’s surface instead of being dragged under by the weight of its long stem because the flexible, hollow stalk is divided into a series of air bladders that buoy it up.
A few insect species are serious water lily specialists, living out their days on the plants. Like Lilypad Forktail damselflies, rarely seen away from them, whose connection is so strong that as they sit on a leaf, the tip of their abdomen is bent down touch it. And like Donacia beetles, whose eggs are laid at the base of the lily leaf and whose larvae attach themselves to the underwater parts of the plant, from which they get both food and oxygen, pupating in a silken cocoon that is dry inside because the air bubbles that leaked from the chewed stem and provided oxygen to the larva have blown the water from the cocoon.
The rhizome of yellow water lily was an important medicine and food of Native Americans (they ate the seeds like popcorn, too), but white water lily was used more for medicine. Henry David Thoreau (that silver-tongued romantic) associated the white water lily with young men picking its flowers on their way to church in Concord, and also said that the flower “reminds me of a young country maiden…wholesome as the odor of a cow.” He reported smoking a stem once and said that it was the “most noxious thing I ever smoked.”
The water lily community has many stories to tell, and the BugLady has already written a few of them. Here’s a tale about some awesome little bugs that she met for the first time at Riveredge Nature Center toward the end of July, 2013 (at the time, BugFan Joanne said, “I’m in wetlands all the time, and I’ve never seen these before!” Ditto!). Some of the water lily leaves hosted masses of the planthoppers for a few weeks, but then they disappeared. Despite searching for them every summer since then, it wasn’t until the summer of 2023 that the BugLady finally found another one (one!).
COMMON WATER LILY/POND LILY PLANTHOPPERS (Megamelus davisi), known in more rarefied circles as the Davis’s Megamelus, are in the bug family Delphacidae, the Delphacid Planthoppers. At first, the BugLady thought they were nymphs, because of their short wing pads, but they were adults. Adult CWLPs come in either reduced-winged (brachypterous) or long-winged (macropterous) models https://bugguide.net/node/view/29578/bgimage, and the brachypterous form is more numerous.
CWLPs are found in the eastern half of the US, but the species has made a surprise appearance in Hawaii. They like ponds and extremely slow streams where white water lilies (genus Nymphaea) grow, and they are also found on the unrelated broad-leaved pondweed (Potamogeton natans). Most of their relatives feed on grasses, but CWLPs eat any part of the water lilies or pondweeds that sticks up above the water line. They’re considered pests if you’re trying to propagate young water lilies, but they don’t damage older, established plants. Another species of Megamelus is welcomed as a biological control of water hyacinth in Florida.
Their nymphs are meals for ravenous water treaders (Mesovelia sp. https://bugguide.net/node/view/1940717/bgimage); they’re attacked by a big-headed fly called Pipunculus varius, and their eggs are parasitized by an exceedingly tiny fairy wasp with the lovely name of Polynema emahttps://bugguide.net/node/view/342131/bgimage, whose range exactly matches that of the CWLP because it has been introduced to Hawaii to hassle them there. When a fairy wasp lays her egg on a planthopper egg, she “marks” it with her ovipositor so other females will leave it alone, because there isn’t enough food in the egg for two wasp larvae to share. CWLPs are also noted in a website dedicated to “Fly Fishing Entomology,” although duplicating a fish food that is less than a quarter-inch long would take dedication, indeed.
Females puncture water lily leaves, stems, and midribs to insert single eggs, and the plant obligingly produces tissue that covers the hole (the nymph’s eventual exit does leave a lasting scar, though). There are three generations each year, and the fall generation, which outlasts the disintegrating water lily leaves, overwinters as almost mature nymphs in the leaf litter of shoreline plants. When they become active again in late spring, they move out over the water and recolonize the lily leaves.
So, what’s this little critter famous for?
First, members of the family Delphacidae are outfitted with spurs (calcars) of various sizes and shapes on their hind tibias (“shins”), but CWLPs are overachievers – their spurs are described as “large,” “moveable,” and even “paddle-like” flaps complete with sensory hairs https://bugguide.net/node/view/1959085/bgimage. There are any number of guesses about what these flaps do for the CWLP. Are they oars that help CWLPs move across the water to new plants? Are they skates? According to a note in the 1923 “Bulletin of the State Geological and Natural History Survey of Connecticut,” “its large spurs undoubtedly support it when, by a mischance, it lands on the water.” Or, queried the “Bulletin of the Buffalo Society of Natural Sciences” (Vol. 5, 1886–97), “Is not the large, foliaceous spur in this species an adaptation of Nature to enable these insects to leap more readily from the surface of the water, about which they make their home?” [This theory seems to be the current front-runner.]
Second, in the “When we try to pick out anything by itself, we find it hitched to everything else in the Universe” category, consider the planthopper-frog connection that has been documented in New York State. Northern cricket frogs (Acris crepitans) love to eat CWLPs during the summer (they also like aquatic springtails). CWLPs are the primary food of cricket frogs as the frogs prepare for their own fall migrations to wintering sites, too. According to the (terrific) New York State Conservationist magazine, “a single cricket frog might spend several hours on one lily pad, devouring planthoppers as they move by the thousands over a lily pad.”
In a paper called “Species decline in an outwardly healthy habitat,” forensic ecologist Jay Westerveld describes the crash of Northern cricket frog populations over much of New York State. It seems that aerial spraying for Gypsy moths (now renamed Spongy moths) in the 1970’s wiped out entire populations of CWLPs. When cricket frog numbers plummeted, investigators noted that they could find no CWLPs where they had once been plentiful. Since spraying isn’t done over public water supply areas, pockets of cricket frogs remain in some wetlands adjacent to reservoirs. Westervelt makes the point that the CWLP is a habitat specialist, and the Northern cricket frog is a food specialist. Because the majority of CWLPs are wingless, natural recolonization by the species is painfully slow, and the bugs may need to be reintroduced in order for the frog to rebound.
Forensic ecologist – the BugLady is ready for the TV series.
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.
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 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 libera) https://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.”)
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.
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 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.
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.
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).
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.
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.
