Bug o’the Week

Early Summer Scenes the Dragonflies

Greetings, BugFans,

Spring was long and cool, an arrangement that the BugLady usually applauds (she savors every little step into spring, and she doesn’t like it when the phenology of six weeks is squished into one or two).  But this year bordered on the ridiculous.  Water warms slowly and steadily (those of us that live in the air often experience dramatic daily fluctuations), so a cold spring means that dragonfly and damselfly naiads, which grow up underwater, are slow to wake up and consume those final calories before emerging as adults.  All of which is a roundabout way of saying that dragonflies and damselflies have been a little late this year, but with some dedicated stalking, the BugLady found some cool things as summer neared, including many tender, young, recently-emerged odonates.

IPSILON DART MOTH   

There’s actually plenty of information out there about the Ipsilon dart because its caterpillar loves to eat a variety of agricultural crops, but (except for one little twist) its biography is pretty straightforward.  It’s one of those species whose adult and larval stages have different names – caterpillars are called Floodplain/Black/Greasy cutworms (one source described the larvae as greasy-looking), and another name for the adults is Dark Sword Grass Moth.  It’s an Owlet moth (family Noctuidae) in the Cutworm/Dart moth subfamily Noctuinae, and its name comes from the roughly “Y’-shaped” markings on the wings and from a misspelling of the Greek letter upsilon, which corresponds with the letter “Y.”  

The Ipsilon dart (Agrostis ipsilon) is a native moth that’s found across the continent into southern Canada and that has traveled around the world (except for very hot or very cold locales).  It’s unwelcome wherever it goes because the caterpillar’s diet includes clover, corn, lettuce, potatoes, tobacco, alfalfa, strawberries, sorghum, sugar beets, cotton, and a variety of grains and grasses.  If the eggs hatch before the crops sprout, the larvae sustain themselves on non-native roadside weeds like pigweed and curly dock and then move into the fields when they’ve finished the “weeds.”  Adults feed on nectar.  Here’s the life cycle https://bugguide.net/node/view/1225712/bgimage. 

Although eggs are laid on low leaves, the caterpillars do their damage below the soil.  There are multiple generations per year in the South; one or two in the North; and the last brood overwinters as pupae.  And here’s the twist – in the northern half of its range, winters are too cold for the pupa to survive.  Adults from the final generation in the north head south to escape the cold (southbound moths don’t reproduce), and in spring, moths migrate north to escape the heat.  According to “Featured Creatures,” a great newsletter of the Entomology and Nematology Department of the University of Florida, “moths collected in the central region of USA in March and April are principally dispersing individuals that are past their peak egg production period. Nonetheless, they inoculate the area and allow production of additional generations, including moths that disperse north into Canada.”

ICHNEUMON ANNULATORIUS

There are so many Ichneumon wasps out there – according to bugguide.net, an estimated 60,000 species worldwide with possibly 40,000 more to discover and describe – so many species that even among those that are named, their life stories are incomplete.  They come in all sizes, shapes and colors; their larvae make a living by parasitizing other insects and even some spiders (and they tend to be very specific about their targets); and they (mostly) don’t sting. 

The BugLady was trying, unsuccessfully, to identify this handsome wasp; she finally asked for help (thanks, PJ), and it turned out to be an Ichneumon wasp.  The BugLady is disappointed that the shiny new wasp book she bought doesn’t cover the Ichneumons, but if it did, she probably couldn’t lift it. 

Ichneumon annulatorius (no common name) can be found in the northeastern quadrant of North America, from Newfoundland to Virginia to Iowa.  Not a lot is known about it, but some of its life history has been inferred from observations of its close relatives.   

In a 1971 article in the Ohio Journal of Science called “Hibernating Ichneumonidae of Ohio.”  Clement Dasch points out that in spite of the fact that ants, bumble bees, and some paper wasps overwinter as adults, hibernation is a relatively uncommon habit in the Hymenoptera (ants, bees, and wasps).  Yet, while looking for hibernating wasps in Ohio, 39 species of Ichneumonids were collected. 

Insects pick their hibernacula carefully, aiming for high humidity and minimal fluctuation in temperature (sunny spots are out).  Ichneumons most frequently chose places under the loose bark of fallen trees on north-facing (shaded) slopes, close to the ground, or in deep ravines.  Other sites included the soft, rotten wood of an old stump or dead wood that was heavily tunneled by other insects.  Some species – including Ichneumon annulatorius – liked thick growths of moss on rocks or trees.  Favorable sites often housed multiple wasps.  

Of the 5,275 wasps he collected, Dasch found only a single male – these species produce a single generation per year, and males died after mating in fall.  Pregnant females entered hibernation by late October and emerged in early April when the air temperatures stayed above freezing, and when they emerged they immediately looked for a host to lay eggs on/in.

GRACEFUL SEDGE GRASSHOPPER

The BugLady was in the Bog on a fine fall day in 2015 when she spotted this jumpy grasshopper on the boardwalk.  It allowed two pictures and then departed.  The BugLady searched unsuccessfully for a grasshopper with the combination of striped head and thorax, glorious red on the femur, and white band on the tibia, and she finally sent it out to a grasshopper expert (thanks Chuck!). 

The Graceful sedge grasshopper (Stethophyma gracile/gracilis), aka the Northern sedge grasshopper/locust (in the short-horned grasshopper family Acrididae) occurs across southern Canada and the northern US, as far south as New Jersey and Nebraska.  It was probably more common 100 years ago, and bugguide.net speculates that it “seems to have disappeared from much of its southern range.”  It’s considered widespread but local, favoring sedge meadows, brushy swamps, stream edges, and other sunny, wet areas, and in the West, it prefers cool uplands.  The grasshoppers live in and eat sedges.

According to an article called “The Orthoptera of North Dakota” in the Proceedings of the Academy of Natural Sciences of Philadelphia (Vol LXXXVII 1925), “it reaches maturity late in the season and is not apt to be found adult before the first of August……”though the males are active, fly vigorously and stridulate loudly, the heavier females are less easily found, then usually ready to leap down into the thickest tangle of grasses at the first alarm.”  The BugLady found an article that suggested that when male grasshoppers stridulate (make noise by rubbing one body part against another) they are more likely to be talking to other males than wooing females. 

Kate Redmond, The BugLady

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

Bug o’the Week

Early Summer Scenes the Dragonflies

Greetings, BugFans,

Spring was long and cool, an arrangement that the BugLady usually applauds (she savors every little step into spring, and she doesn’t like it when the phenology of six weeks is squished into one or two).  But this year bordered on the ridiculous.  Water warms slowly and steadily (those of us that live in the air often experience dramatic daily fluctuations), so a cold spring means that dragonfly and damselfly naiads, which grow up underwater, are slow to wake up and consume those final calories before emerging as adults.  All of which is a roundabout way of saying that dragonflies and damselflies have been a little late this year, but with some dedicated stalking, the BugLady found some cool things as summer neared, including many tender, young, recently-emerged odonates.

The family Calliphoridae (Blow flies) includes Carrion flies, Blow flies, Bluebottle and Greenbottle flies, Cluster flies, and the notorious Screwworm flies.  These often-metallically-colored flies are common in many habitats around the world, including urban areas, where they bask on sunny walls.  The name Blow fly (which was coined by William Shakespeare) comes from an old English term for meat that flies have laid eggs in – such meat was said to be “fly blown.” 

Most Calliphorid larvae (maggots) make their living as recyclers, which conjures up a more wholesome image than does saprophagous (feeding on decaying organic material) or sarcosaprophagous (“feeding on decaying animal material”) (to complete the set, scato/coprophagous refers to feeding on excrement and phytosaprophagous to feeding on rotting plant material.  Quadruple word scores all around).  Maggots eat dung and/or carrion, excreting proteolytic enzymes that break down its proteins, and a few species are parasites.  

Adult blow flies get carbs from nectar and are minor pollinators (they’re attracted to flowers with strong, “meaty,” odors), but they also visit carrion and dung to get protein.  The BugLady photographed one fly as it fed on sap that was leaking from the cut trunk of a small tree in early spring.   

In a blog post titled “Ten reasons why blow flies are stink’n awesome” from the Insect Ecology and Communication Lab at Ohio University, the author writes, “……All joking aside though, blow flies don’t really smell, it’s the resources they are associated with (garbage, poop, carrion, etc.) that smells. The purpose of this post is to make you fall in love with appreciate blow flies! Blow flies are considered filth flies because they are a terrible nuisance to people and are thought of as disease vectors.  Overall, blow flies have a bad reputation because of their less than socially approved eating habits (the BugLady is not going to list the ten – read the article https://bekkabrodie.com/2014/05/20/ten-reasons-why-blow-flies-are-stinkn-awesome/).  On the negative side – you know where that mouth and those feet have been.  On the plus side – they don’t bite.

Experienced BugFans can see where this is going.  The BugLady will try to tell the story as delicately as possible, but this lifestyle is just a part of the magnificent panoply that is the insect world and, well – blow flies happen.

THE BLACK BLOW FLY (Phormia regina), the only species in its genus, is a cold-loving fly that can be found across North America and around the world, especially in rural areas near water.  It’s seen more commonly during spring and fall in the northern half of its range, and in winter in the southern half.  In an article in the Martha’s Vineyard Times, Matt Pelikan (who writes nice natural history articles) says “Nobody seems to know where it originated; perhaps it had succeeded in colonizing much of the globe on its own even before human commerce began transporting wildlife from continent to continent. Or perhaps Phormia began hitching rides so early on in human history that it was already established most places by the time the first biologists turned up and began looking at flies.”

Both male and female Black blow flies need protein to fuel their mating and reproductive activities, and they get this protein from dung, which they ingest via “sponging” mouthparts.

Adults emerge from their winter shelters under tree bark and fallen leaves (sometimes putting in an appearance during a January thaw), and when the air warms consistently to about 50 degrees, the dance begins.  In the case of Black blow flies, the singles scene revolves around animal droppings, and males with larger hat sizes tend to be more successful at getting the gals.  After mating, the female “sniffs” the air, and tracks down some carrion.  Although adults get their nutrients from animal droppings, their eggs are laid on dead meat (up to 250 eggs, in various nooks and crannies).

The eggs hatch quickly in their meaty substrate; they have three instars (the eating stages between molts), and a feeding, metabolizing mass of third-stage maggots generates so much heat that the temperature within the mass can be 50 degrees F (or more) warmer than the ambient temperature.  It’s called the “maggot mass effect,” and it not only keeps everyone toasty, it gooses development and protects against predators and parasites.  The larvae survive the stress of this shot of heat by creating “heat shock proteins” (the BugLady was going to attempt a brief explanation of heat shock proteins, but she got into deep water pretty fast).  Maggots leave the nursery carcass and form pupal cases on the ground; their run from egg to pupa can be as brief as 6 days, with an additional week in the pupal case, but in cooler temperatures they may take up to 12 days longer to mature.  The faster their development is, the smaller the adults are. 

Sources disagreed about whether Black blow flies routinely come inside (most say no), but one suggested that if you see a cluster of blow flies in/around the house, they might be attracted to the odor of a gas leak.

Black blow flies are exquisitely sensitive to the smell of a recently dead animal.  They are among the first to arrive at the scene, which is why they are favorites of the CSI folks and why their chronologies have been so minutely charted. 

Another service provided by a number of blow flies, including the Black blow fly, is wound care (called biotherapy or maggot therapy).  Super-clean maggots are applied to open wounds with stubborn infections because those proteolytic enzymes break down the necrotic tissue for the maggots to eat and leave the healthy tissue alone.  Pick your blow flies carefully – some species (but not this one) sweeten the pot by adding antibiotic secretions to the wound, and other species will feed on healthy tissue.  Unwanted maggot infestations are called myiasis, and they happen to livestock (mostly), in warmer climes (mostly).  

Final Cool Fact about Blow Flies, from the Insect Ecology and Communication Lab “Blow flies are able to fly with such precision that we are never able to swat them.  This is because of the very tiny second pair of wings called halteres, which function like mini gyroscopes and help the fly to calculate in flight maneuver instantly.  Scientists use Blow flies to study flight muscles and split second flight maneuvers. They have discovered flies in mid-turn have the ability to roll on their sides 90º or more (flying upside down) just like a jet fighter.”

According to a 1922 report of the Kansas State Board of Health, “The robin and the bluebottle fly are the early harbingers of spring.”

Kate Redmond, The BugLady

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