BUG OF THE WEEK
Week 26 - 30
Week 26: Moth Madness
The day-flying moth, the Virginia Ctenucha Moth, is about 1 ½” long and is fairly common in the northeastern quadrant of the United States. When disturbed it can, like many moths, be mistaken for a butterfly. But, it flies quickly toward vegetation and darts under a leaf to hide, which is generally un-butterfly-like. For a “plain” dark moth, it’s pretty spiffy, with iridescent blue on the thorax and abdomen, an orange head and yellow tarsi (feet). Some species of ctenucha moths mimic wasps and poisonous beetles and so are left alone on flowers.
Ctenucha moths are sometimes mistaken for butterflies.
Ctenucha moths spend the winter as caterpillars.
Like the more familiar Wooly Bears, Ctenuchas are in the Tiger moth bunch. They overwinter as caterpillars and pupate in spring in cocoons which they construct using their own hairs. When disturbed, the caterpillars protect themselves by curling up into a ball, which, in the case of the Virginia Ctenucha, reveals its white lateral streak. The caterpillars primarily eat grasses, and both the caterpillars and the adults are found in fields and meadows. The Bug Lady photographed the caterpillar along a damp, gravel road in the early warm days of April, 2008.
The “C” is silent like the “r” in “fish.”
Underwing moths are a huge and confusing group.
There are more than 100 species of underwings in North America, mostly in the East. They have variously striped hind-wings – black with white or with various intensities of pink - that are designed to startle their predators when the moths are in flight. At rest, with the fore wings covering the hind wings, they are admirably well-camouflaged.
This nifty moth is probably the Sweetheart Underwing, Catocala amitrix, which measures three to three-and-a-half inches long and is found over a wide section of the eastern U.S. Catacola caterpillars tend to look like little twigs; many have a fringe on their sides which blurs their outlines and makes them blend onto what they are sitting on. They turn up their noses at older leaves and feed only on new vegetation. Like many caterpillars, they are “food specialists” – the biologist’s way of saying “picky eaters.” The caterpillar of this species feeds on willow and poplar.
Underwing moths chow down on oranges at night.
The Bug Lady puts oranges out for the birds in summer, and at night she finds the lovely White Underwing, with its black and white hind wings, feeding on the oranges. BugFans can bait moths by spreading a mixture of fermented fruit, brown sugar and beer on tree trunks. Check the bait nightly for feeding moths and underage drinkers.
The BugLady highly recommends, if you can find one, “The Moth Book” an old classic by W.J. Holland (published in 1903 as part of the “My Nature Library,” a series which the Bug Lady devoured as a naiad and which was republished by Dover in 1968). Though some of the classifications/scientific names have has changed, it has plates showing hundreds and hundreds of moths.
Week 27: Crayfish
More than 300 species of crayfish blanket North America.
Hello again BugFans,
Crayfish are classified in the Phylum Arthropoda (“jointed legs”), the Class Crustacea (referring to their hard, outer coverings), and the Order Decapoda (“ten legs”). , They are found throughout the continent, although the Rocky Mountains and western Great Plains have historically been fairly crayfish-free. Crayfish inhabit shallow waters, running and still, and some live in damp-lands away from standing water and even at the base of a hillside where run-off from above provides their moisture (and yes, the BugLady is using a rather catholic definition of “bug” in order to include them under the “Bug” umbrella.”)
A carapace covers the cephalothorax (fused head and thorax). The “snout” that protrudes from the front of the carapace is called the “rostrum.” Antennae, stalked eyes, and five pairs of walking legs decorate the cephalothorax; gills and a balance organ, into which the crayfish incorporates grains of sand as sensors, are located inside it. The abdomen also has small appendages on it and consists of six segments terminating in a flipper-like “tail.” Crayfish move forward by creeping, and they can move backward by quickly tucking/folding their jointed abdomen under them several times; they can also walk sideways. Crayfish can regenerate lost limbs.
Crayfish (crawfish, crawdads) are omnivores and often scavengers, feeding on dead plants, live plants, snails (mainly those species with thinner, more crushable shells), aquatic insects, small fish and carrion. The largest claws, on the front pair of legs, crush or rip their food (When she was in an earlier instar, the Bug Lady used to angle for crayfish using raw bacon as bait, which both she and the crayfish thought was mighty tasty). Crayfish are eaten by raccoons, otters, screech owls, lots of fish, and by humans, who should cook them well in order to avoid a lung fluke that crayfish play intermediate host to in the eastern part of their range.
According to the excellent A Guide to Common Freshwater Invertebrates of North America, by J. Reese Voshell, Jr., crayfish are an important domino in aquatic ecosystems. Their actions may determine the density of the aquatic plants, which determines the health and composition of the accompanying animal community.
The aggressive Rusty crayfish (Orconectes rusticus), is an “invasive native” (native to the Ohio River Basin, that is) that has achieved pest status in Wisconsin. Rusty crayfish were probably introduced by bait fishermen and aquarium owners discarding unwanted animals into ponds and waterways, but they are also sold to schools by biological supply companies. They are aggressive toward native crayfish, toward the fish that would normally eat them, and toward the toes of wading humans. They eat twice as much as native crayfish, and they impact fish populations by eating fish eggs, small fish, insects eaten by fish, and aquatic vegetation needed by fish for cover and for spawning areas. Pretty much a clean sweep, damage-wise.
Crayfish chimneys are act as a humidity control.
Species that live in drier conditions or whose aquatic home dries up in late summer build “chimneys” in an attempt at climate-control. In search of water to keep their gills moistened, these relative landlubbers excavate vertical tunnels in the earth, constructing at the mouth of the tunnel a cylindrical pile of mud pellets – a chimney. There they live, in damp and solitary splendor (except for a bit of co-habiting during the breeding season). The Bug Lady’s youngest child once wrote in a poem that “crayfish build chimneys so their voices will echo when they sing.”
Week 28: Red Admirals
Red Admirals belong to the Nymphalidae or Brush-foot family, the largest butterfly family; their antennae are very “knobbed” and their front pair of legs are reduced in size and covered with bristles. They are in the genus Vanessa, a genus that includes the Painted Lady and American Lady. Vanessas are widely distributed across the US (and temperate regions in Europe, northern Africa and Asia) and occasionally have large population irruptions and wander. Red admiral adults and pupae are found in the south during the winter, and migrating admirals repopulate the north each spring. According to Ebner, in “The Butterflies of Wisconsin,” a few individuals may overwinter as adults in Wisconsin, emerging in the balmy days of late April and May.
There are two broods a summer in most of the north. The spiny caterpillar eats spiny nettles; a caterpillar folds a leaf or leaves around itself, webs it/them shut, and feeds, protected, inside. It may pupate there.
Red admirals love sunny lawns and forest edges.
Red admirals are less conspicuous with wings folded.
A Painted lady may be mistaken for a Red Admiral.
Another butterfly confused with the Red Admiral is the Milbert’s tortoiseshell.
The males set up territories in clearings and semi-sunny edges in the late afternoon. This was the Bug Lady’s favorite butterfly when she was in an earlier instar; if she stood for a while on the lawn, a red admiral would fly over and sit on her out-stretched hand and sometimes eat a little salty sweat. A small vignette in the formation of a Bug Lady.
One older source says that butterflies and moths void a drop of liquid (red, in some species) soon after leaving their pupal cases. They sometimes do this while airborne, and when large numbers of butterflies emerged simultaneously, the phenomenon, called “Red Rain” was in ancient times and is today the subject of wild religious fear, superstition, repentance and/or massacre.
The BugLady recommends Door 3, repentance.
Week 29: Walkingsticks
Northern walkingstick, Diapheromera femorata.
Walkingsticks are available in green or brown (a few species can also change color slowly, and the BugLady has slides of a really spiffy individual that mimicked the speckled and streaked shoots of a box elder). Local walkingsticks may reach 4” in length (males tend to be smaller) but the largest North American species can grow to a whopping 7 inches, and tropical species may reach 12 inches. Most species are wingless. Since insect legs (and wings) are attached to the middle section, or thorax, it’s apparent that a walkingstick’s thorax comprises an impressive portion of its body. A walkingstick that loses one of those spectacular legs is able to regenerate it, completely or partially.
Extending the front legs makes it more “stick-like.”
Shy and nocturnal, they graze on leaves of forest trees and, during a population boom, can damage them. There are two reasons for camouflage – to hide and to hunt. Along with their physical appearance, walkingsticks practice “behavioral camouflage.” During the day they extend their front and rear legs to the fore and aft of their body and remain motionless or sway slightly in the breeze. Turns out that despite one of Mother Nature’s better camouflage jobs, many predators aren’t fooled; walkingsticks are spotted and eaten by a variety of songbirds, rodents and mantises. Two species of Florida walkingsticks have added chemical warfare to the usual arsenal of passive defenses, squirting a highly irritating liquid into the face of a potential predator and earning themselves the nickname “Musk-mare.”
As females negotiate the trees in early autumn, they drop eggs that free-fall to the ground. These will hatch next spring – or the one after that. Metamorphosis is Simple/Incomplete – the newly-hatched young pretty much resemble the finished product, simply growing (often changing color,) and adding adult parts as they molt. Some species, like the aphids of recent BOTW fame, practice parthenogenesis (virgin birth).
Formerly classified, along with the Mantises, in the grasshopper Order (Orthoptera), WalkingSticks are now in their own Order, the Stick Insects or Phasmatodea.
The BugLady was casting about for one final interesting factoid with which to finish this account, and she discovered two, in “The Handy Bug Answer Book” by Dr. Gilbert Waldbauer:
First, parental care is necessarily absent in a group where Mom drops her eggs to the ground from the tree tops, and the forest floor is fraught with dangers for the hapless eggs, including cuckoo wasps that search for walkingstick eggs to parasitize. Because a portion of the outside of each egg is edible, ants carry the eggs below-ground to their nests. Their nibbling does not damage the interior of the egg, and when the tiny walkingsticks hatch, they are allowed to exit the ant hill.
The second factoid includes some “adult content,” and the BugLady requests that you cover the eyes of impressionable children and innocent maidens - if you know any. Fidelity is rare in the insect world, and there are a number of strategies that males of some groups may use to ensure that the object of their affections does not court another. Some male walkingsticks are known to, ah, remain “in the embrace” of a female long after sharing bodily fluids with her, becoming what Waldbauer calls “living chastity belts.” In fact, the, um, endurance record for copulation for the insect world seems to be held by walkingsticks.
A northern walking stick casts a big shadow.
Week 30: Milkweed Critters
Milkweeds and goldenrods are famous for being hosts to a tremendous variety of insects and other arthropods that come to eat or be eaten. Both adult and immature insects that eat milkweed at some part of their life cycle are poisonous to their predators because of the toxic cardiac glycosides contained in milkweed sap. The BugLady read of one study in which, after captive Blue jays were fed monarch caterpillars, they threw themselves against the sides of the cage to avoid the next batch of caterpillars that was put into the cage. Here are a few milkweed critters; there are also some pretty spiffy weevils that like milkweed, and it is a cafeteria for many grasshoppers, plant bugs, butterflies, ants, wasps and even small frogs.
There are about a dozen species of milkweed beetles, Tetraopes, north of Mexico.
Red milkweed beetles from New Jersey have heart-shaped spots.
Red milkweed beetle are members of the long-horned beetle family (Cerambicidae), a spectacular group of beetles that can be both colorful and large and that bear long (sometimes very long) antennae. Typically, the adults are plant-eaters (wood, leaves, pollen, flowers) and the grubs feed on wood. The family has lots of members that are pests on lumber, mainly after a tree is cut. This guy mainly chows down on common milkweed; its grubs feed on stems and roots of milkweed and overwinter within the stem. Their nickname – four-eyed beetles – is the result of the socket of the antennae being located in the center of the eyes, “dividing” them in two.
A Swamp milkweed leaf beetle looks like an overgrown ladybug.
(Swamp) Milkweed Leaf Beetles look like overgrown Ladybird beetles (of previous BOTW fame). They browse on the leaves and sometimes the flowers of milkweeds, and they do not, obviously, restrict their presence to swamp milkweeds (one field guide calls them, simply, Milkweed Leaf Beetles). Like other insects in this episode, they wear Mother Nature’s warning colors to advertise their toxicity. They overwinter deep in the fuzzy basal rosettes of mullein plants. According to Kaufman in his excellent Field Guide to Insects of North America. the adult beetles will sever the veins of a milkweed leaf to let the sap run out before feeding. When startled (by, say, a photographer) they bail, jumping off the leaf and hiding in the vegetation on the ground.
Milkweed tiger moths are sometimes called Harlequin caterpillars.
Milkweed Tiger moths are (in addition to Monarchs) the other common milkweed-leaf-eating caterpillar. Unlike the solitary Monarchs, they are often seen in groups on milkweed. The adults are anonymous-looking silvery-white moths with ragged wing edges.
This guy/gal is burrowing into a pod to eat the developing seeds.
Small Eastern Milkweed bugs lay their eggs on milkweeds in spring, nymphs spend the summer on milkweeds, and adults overwinter. Most members of the “Seed Bug” family are plant eaters; milkweed bugs feed on milkweed seeds.
Monarch caterpillars look pretty much the same coming or going.
Monarch caterpillars feed on milkweed leaves, and the adults eat nectar from a variety of flowers. There are many generations per year, but those that emerge at the end of summer migrate to Mexico; all the monarchs east of the Rockies overwinter on the same mountainside in Mexico. In spring, the generation that migrated south starts north. They lay eggs as they go and the new generations are the ones that return to Wisconsin.
Have you hugged a milkweed today?
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