|Leaf-Footed Bug - Acanthocephala terminalis|
Family Coreidae - Leaf-footed bugs, squash bugs, clown bugs, tip-wilters
Live adult leaf-footed bugs photographed in the wild at northern Illinois. Size = 25mm
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Identification: Almost uniformly dark chocolate brown or reddish brown. Tibia frequently pale yellow. First three antennal segments also brown; 4th segment contrasting pale yellow to orange, but sometimes nearly white. Humeral angles of pronotum obtusely rounded with tubercules poorly developed or absent; dorsal surface of pronotal disc usually prominently tuberculate.
Outer dilation of hind tibia well-developed, but strongly tapered on distal 1/3 so that this area does not appear to have an outer dilation. Very similar to confraterna, and these species are difficult to tell apart in areas where their ranges overlap.
Biology: A common species found on many trees and shrubs along woodland margins and meadows. Favored host plants include hickory, goldenrod, boneset, and Joe-Pye weed. Generally only one generation per year, with adults overwintering. 
The Hemiptera family Coreidae includes leaf footed bugs and squash bugs. Leaf footed bugs are named for their leaf-shaped expansions of the hind tibia and femora. They have four-segmented antennae, large compound eyes and one pair of ocelli, or simple eyes.
All species of Coreidae are phytophagous, that is, plant-feeders. Like all true bugs, the adults are equipped with a beak, or rostrum, a hypodermic needle-like device carried under the head, which it uses to pierce the plant tissue and suck out liquids. They do not simply "suck out sap", they inject a tissue-dissolving saliva and vacuum out the resulting slurry. Bugs cannot ingest solid food, and widespread damage to the plant is a result of these liquefying enzymes. 
Some Coreids live in leaf litter, but most nymphs and adults live above ground on their host plants where they may feed on seeds, fruits, stems or leaves. Many occur on an astonishing variety of plants, while some are restricted to a single host. Most Coreids do not appear to have the numbers to become serious agricultural pests, however some become a problem through their feeding on a single variety of plants; the most destructive of these is probably a squash bug, (a common name applied to bugs in the genus Anasa) Anasa tristis, which is a pest of cultivated cucurbits. 
I find the Coreidae engaging creatures, being so large and stately - they don't scare easily and don't seem to mind posing for pictures - although this one disappeared rather suddenly, with a quick launch from those strong hind legs and a burst of speed from the huge flying wings.
Coreids and other bugs are frequently parasitized by flies in the family Tachinidae and wasps in the Hymenoptera families Encyrtidae and Scelionidae.  The leaf-footed bug above is the unfortunate bearer of an egg cemented to its pronotum, probably placed there by a tachinid fly.
Trichopoda plumipes (below) and others in the genus are particular to Acanthocephala terminalis.  Eggs are laid directly on the adult bug, most frequently on the pronotum as above. When the egg hatches, the larva burrows into the bug, where it develops, eating the bug's insides - but generally avoids killing the bug until it emerges as an adult fly. 
Tachinid fly Trichopoda plumipes frequently lays eggs on adult Coreidae.
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Hemiptera was first recognized by Linnaeus in the Systema Naturae of 1758.
True Bugs species number almost 5,000 in North America, and 40,000 worldwide. Bugs have hypodermic needle-like mouthparts that allow them to extract fluids from plants and animals. Hemiptera Index
Suborder Auchenorrhyncha - Cicadas & Planthoppers
Suborder Sternorrhyncha - Aphids, scales, mealybugs, jumping plant lice