For the past few years, the BugLady has been monitoring an odd development among a patch of common milkweeds along her driveway. Two years ago a few sickly milkweeds sprouted among the healthy ones. There were more diseased plants last summer, and this year the proportion has increased to approximately half of the milkweeds in a fairly dense patch.
The Pole Borer can be found during warm months—even marginally warm ones—in/near woodlands in the eastern half of North America. It has the distinction of having been exported to Europe, arriving in Germany during WWI or possibly earlier. A female pole borer excavates clusters of holes in wood, probably using both ends, her mandibles and her ovipositor. She deposits a single egg per hole. The larvae start at ¼ inch and grow to 1 inch, chewing tunnels called galleries into crossties, telephone poles and structural wood and into trees that are already wounded and starting to decompose.
With the exception of South America, Flesh Flies are common around the globe. They are outdoor flies, preferring the intersect where dung/decaying plants/decaying flesh meet daylight. The larvae of some species act as biological controls that eat or parasitize snails, wasps, bees, beetles, grasshoppers, forest tent caterpillars, and some fellow flies, but as a group, they are scavengers on dead stuff.
Milkweed Bugs are in the Seed Bug bunch (family Lygaedidae), which get their name because they suck juice from seeds. MBs of one kind or another are found on milkweeds across the U.S. and southern Canada, and they are most common in the Southeast. Unlike most insects, MBs are reported to feed on some nectar, and when food is scarce, MBs may eat other milkweed parts and live or dead invertebrates.
Fall Webworms are found in North America from coast to coast and border to border. They are native sons and daughters that have, since WWII, spread through Europe and Asia. Look for them in parks, forest edges, and roadsides. Cherry leaves are a favorite caterpillar food, but they will dine happily at quite a variety of trees including ash, willow, poplar, hickory, American elm, walnut, some maples, and a few fruit trees. A colony of caterpillars can eat lots of leaves, and they may defoliate part or all of a tree.
The BugLady’s advice for the day is: Find yourselves a big clump of goldenrod and start looking. Bring your camera. Bring a lawn chair. What will you see?
Box Elder Bugs, as you would expect, feed on/suck sap from the tender parts of box elder trees, especially from the seed pods (some municipalities ban female box elders for this reason). They have been observed eating other maples, ash, and a few species of fruit trees, plus grapes and strawberries, and their feeding may scar fruits. They can fly several city blocks, or up to a few miles looking for food.
Dogbane Leaf Beetles are oval-ish, mostly measure less than a half an inch, come in bright colors, have un-spectacular antennae, smallish heads often shielded by a large-ish prothorax (first segment of the thorax), short legs, and domed elytra. The DLB’s incandescence is the result of the play of light on exceedingly small, tilted plates that overlay its pigment layer. Light bounces off both the pigment and the plates, and the colors change with the angle of the observer.
Swamp Metalmark populations are in trouble, and the species is listed as rare/endangered in the areas where it is known to live. Why? Its habitat needs are very specific (location, location, location); its caterpillar eats a single, uncommon species of thistle; the adults nectar on only a half-dozen or so flowers; and they don’t stray far from their never-common-and-increasingly-rare habitat.
Hairy Rove Beetles are found during temperate months in woods east of the Mississippi and also across The Pond. There they mostly hide out under stuff—dead bark, rocks, leaf litter, dung and carrion. Most rove beetles are carnivores or scavengers as both adults and larvae, but a few species eat mushrooms and plant materials. The HRB is counted among the insect tools of Forensic Entomologists who determine post-mortem intervals.