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General Entomology EEB 286 University of Connecticut Fall 2006 Hemiptera 1 Page 1 HEMIPTERA NAME ORIGIN: Gk. hemi – half; pteron – a wing. INTRODUCTION: True bugs. The largest non-endopterygote lineage with over 80,000 species described worldwide and at least 3,834 species documented from North America. As with all hyperdiverse insect groups, much work remains to be done even at the level of basic taxonomy, natural history, and faunal inventory. RECOGNITION: • piercing-sucking mouthparts • usually 4 wings; forewings divided into proximal “leathery” and distal membranous regions • cerci reduced or absent HABITATS: Most Hemiptera pierce plant vascular tissue with their mouthparts and imbibe liquid contents. Only the Heteroptera contains species that are predatory and suck animal liquids, and a few Heteroptera are fungivorous or ectoparasitic on vertebrates. Some sternorrynchans are essentially sessile (e.g. scale insects). COLLECTING: Sweeping captures many Hemiptera. Numerous families are aquatic. A few species are marine. Immatures and soft-bodied adults (aphids and some scales) are usually too soft to pin and must stay in EtOH. Some Hemiptera have fragile legs and antennae that will break if handled roughly, even in EtOH. TAXONOMY: Traditional classifications list 2 orders: the Hemiptera and the Homoptera. Current texts use a classification more representative of relationships within this lineage. The phylogeny below shows the traditional Homoptera as being paraphyletic and comprised of two lineages that are given suborder rank in modern texts: the Sternorrhyncha and the Auchenorrhyncha. The Heteroptera in recent texts is the same clade as the Hemiptera of older texts. The Heteroptera share half-thickened fore wings which, when folded across the back, produce an "X" pattern. Homoptera Sternorrhyncha Auchenorrhyncha Heteroptera General Entomology EEB 286 University of Connecticut Fall 2006 Hemiptera 1 Page 2 Suborder Heteroptera (true bugs) • • • forewings leathery in basal half, membranous apically, folded flat over abdomen; hindwings membranous mouthparts sucking herbivorous or predaceous Family: Nepidae (waterscorpions) • body slender and elongate or elongate-oval • front legs raptorial • remaining legs long, cursorial • end of abdomen with long breathing tube • exclusively predaceous • can inflict a painful bite Family: Belostomatidae (giant water bugs) • body oval, flattened • front legs raptorial • hind legs somewhat flattened, adapted for swimming • can inflict a very painful bite • may reach a length of 65 mm • predaceous on insects and small vertebrates Females of Belostoma and a few other genera lay their eggs on back of the male, which then carries them around until they hatch. Most other genera lay their eggs on aquatic vegetation and don't exhibit any parental care. Belostomatids frequently leave the water and fly about, and because they are often attracted to lights, they are sometimes called electric light bugs. Family: Corixidae (water boatmen) • body elongate-oval, 6-12 mm long • dorsal surface flattened, with narrow dark crosslines • front legs much shorter than mid legs • head wider than thorax • hind legs elongate, oar-like • swim dorsal side up • feed on algae, a few predaceous General Entomology EEB 286 University of Connecticut Fall 2006 Hemiptera 1 Page 3 Family: Notonectidae (backswimmers) • • • • • • • • body elongate-oval, about 15 mm long dorsal surface strongly convex, often light colored, without crosslines head narrower than thorax front legs only slightly shorter than middle legs hind legs very long, oar-like swim upside-down predaceous, feed on small aquatic arthropods and vertebrates can inflict a painful bite Family: Gerridae (water striders) • body slender, usually longer than 5 mm • middle legs closer to hind legs than to front legs • legs very long • apterous or winged • run on water surface using surface tension • predaceous – feed on insects that fall onto water surface; also scavengers Family: Veliidae (riffle bugs) • body slender, usually less than 5 mm in length • middle legs more or less equidistant from front and hind legs • legs relatively short • claw located before tip • body widest near base of middle or hind legs • run on water surface using surface tension