Hemiptera Family Characters

STERNORRHYNCHA

Psyllidae: Diagnostic characters: small (2-5 mm); 2 pairs of wings in both sexes, held roof-like over body, forewing often thicker than hind wing; resemble miniature cicadas; strong jumping legs; antennae 10-segmented; tarsi 2-segmented, with 2 claws.

See the Psylloidea Web Page from the USDA's, Systematic Entomology Laboratory. Psyllids, or jumping plant lice, feed on phloem sap, and are usually very species specific; a very few produce galls such as the hackberry nipple gall psyllid, Pachypsylla celtidismamma, and Psylla magnicauda.   The nymphs live inside the galls. Eggs laid shallowly in plant tissue and covered with wax. Nymphs do not closely resemble adults and produce copious powdery wax.   Adults resemble miniature cicadas and are active jumpers and fliers. Two important pest species, both introduced from Europe, are the pear psylla, Psylla pyricola, and the apple sucker, Psylla mali. Nymphs feed on axils of leaves and fruit and produce copious honeydew on which fungus grows; infected trees shed leaves and fruit.

Aleyrodidae: Whiteflies. Diagnostic characters: minute (2-3 mm); 2 pairs of wings in both sexes; forewings about equal in size to hind wings; body and wings covered with a white waxy powder.

See the USDA's Systematic Entomology Laboratory Whitefly Web Page. 1st instar nymphs are active, but later nymphs are sessile and scale-like.   The group is abundant in the tropics.   One important species affects citrus - fungus growing on honeydew interferes with photosynthesis. Other species are important greenhouse pests.

See the Aphidoidea World Wide Web Page from the USDA's, Systematic
Entomology Laboratory. Cornicles secrete defensive substance. Some secrete wax. Honeydew secreted from anus. Often milked by ants. Honeydew "rain."

A good discussion of the complex life cycles (heterogamy) of aphids can be found on the Tree of Life, of which one example is the following:

--Eggs overwinter
--Hatch in spring into parthenogenetic female fundatrix, usually wingless, primary host plant
--Viviparous birth to wingless females, apterae (several generations)
--Birth to winged female, alatae, migrate to secondary host plant
--Parthenogenetic birth to several generations of female apterae on secondary host
--Produce alatae, migrate back to primary host plant
--Birth to male & female (sexuparae), sexual reproduction - oviparous female (ovipara) produce fertilized eggs from which fundatrix hatches.

Enormous numbers can build up. Many serve as important vectors of plant viruses, which cause severe economic loss to crops. Important historical collection and research at U of Minn (Oestlund, Granovsky).

Aphididae: Diagnostic characters: winged or apterous; forewings much larger than hind wings, forewing with 4, 5, or 6 veins behind stigma; antennae usually 6 segmented; pair of cornicles usually present near posterior end of abdomen. Examples: Rhopalosiphum maidis and Aphis pomi.

Adelgidae: Diagnostic characters: forewing with only 3 veins behind stigma; antennae 3-5 segmented; cornicles absent. Pine and spruce aphids. Feed only on conifers.   Primary hosts (where galls often formed) and secondary hosts, both conifers.   Complex life cycles.   Eastern spruce gall aphid.

FYI: Eriosomatidae: Wooly and gall-making aphids. Cornicles reduced or absent, profuse wax producers.   Adults lack mouthparts. Female produces only 1 egg.   Also with complex life cycles.   Primary host plant (tree or shrub), secondary host plant (herbaceous).   Often produce gall on primary host.   Woolly apple aphid.

FYI: Phylloxeridae: phylloxerans, including the grape phylloxera, an important pest on grapes, especially in Europe. Complex life history. Causes galls on grape leaves and gall-like swellings on roots, with many aphids inside.

Scale insectds and mealybugs, superfamily Coccoidea: See the Coccoidea Web Page from the USDA's, Systematic Entomology Laboratory.

Diagnostic characters: very highly modified; female wingless, usually legless, sessile; male forewing developed, hind wing reduced to style-like processes, long antennae, long style on end of abdomen, lack mouthparts, do not feed. Complex life cycles. 1st instar nymphs active "crawlers", 2nd instar legs and antennae lost, sessile, waxy or scale-like covering over body. Female remains here. Male develops wings.  

Some coccoid families:

Coccidae Diagnostic characters: abdominal spiracles absent; anal opening covered by two plates. Soft scales, wax scales, tortoise scales - many citrus, greenhouse, and house plant pests; Chinese wax scale - males produce pure white wax for making candles.

Diaspididae Diagnostic characters: beak and antennae on segmented; legs absent or vestigial. Armored scales - Largest family in North America, with very important pest species.   Scales from wax as well as cast skins. Very different shapes of scales. Injure plants by sucking sap. San Jose Scale, oystershell scale.

PseudococcidaeDiagnostic characters: in life covered by white, powderly secretion. Mealybugs - female body segments distinct, with legs. 300 spp. in North America. Citrus, greenhouse, and house plant pests.

FYI: Margarodidae — Giant coccids and ground pearls (large, to 2.5 cm); cottony cushion scale - pest of citrus in West.

FYI: Kerridae — Lac scales - Indian lac insect-source of shellac; others sources of pigments.

FYI: Kermesidae — Gall-like coccids - on twigs and leave of oaks in US. Tamarisk manna scale, Trabutina mannipara, on Tamarix, female produce large amount of honeydew, in arid regions it solidifies and accumulates in thick layers; sweet.

FYI: Dactylopiidae — Cochineal insects - female red in color, occur on cactuses; source of crimson dye; female collected and dried, and pigments extracted.

AUCHENORRHYNCHA

Cicadidae: Diagnostic characters: large insects with large wings; forewing membranous; 3 ocelli.
Cicada immatures live in the ground and feed on plant roots. The immature life span last for several years in the dog-day cicadas and up to 13 or 17 years in the periodical cicadas. Dog-day cicada adults emerge during the "dog days" of summer in the northern hemisphere - late July to September in Minnesota. There are 7 species and over a dozen broods of periodical cicads in the US, but none occur in Minnesota. Some broods emerge in such large numbers as to cause sensational news stories and public interest, as occured in the mid-Atlantic states during the summer of 2004. Feeding by the immatures is of little economic importance, but damage to twigs of trees and shrubs can occur because of female oviposition. Cicadas are among the most boisterous of the sound producing insects, with species specific calls.

Examples: A dog-day cicada, Tibicens resh; male T. resh showing operculum of sound producing organ; female showing ovipositor. Size range in cicadas, the giant Pomponia imperitoria from Malaysia and the small Pacarina puella from Texas; Linnaeus' 17-year cicada, Magicicada septendecim; a Costa Rica species, Zammara tympanum, with pronotal flanges.

Cercopidae: Diagnostic characters: small jumping insects; hind tibiae with 1 or 2 stout spines, and usually a circlet of spines at apex.
Spittle bugs or froghoppers are best know for the frothy spittle produced from the anus and abdominal glands of the immatures, which covers them while they feed on grasses. These insects are very common, especially in meadows, but only a few might be considered pests. Examples of cercopid diversity, 1, 2; tibia showing arrangement of spines.

Membracidae: Diagnostic characters: small jumping insects; pronotum projecting backwards over abdomen, often highly developed (especially in tropical species).
Tree hoppers feed on trees and shrubs where they display a rather narrow host range. Tropical species are known for the bizarre ornamentation of their pronota. The adaptive value of these ornamentations include crytic resemblance to thorns and twigs, sexual display, and apophysectomy. Some species show a primitive form of sociality, with the female tending her eggs and offspring while they mature. Examples of membracids, showing remarkable diversity of pronota: a common Minnesota species; Costa Rican, Mexican, and Brazilian examples; other, mostly Neotropical, examples, 1, 2.

Cicadellidae: Diagnostic characters: hind tibiae with 1 or more rows of small spines.
Leafhoppers comprise a very large, species diverse, and economically important family. They feed on the leaves of plants, which in crop species causes economic damage by sapping the plant of nutrients, damaging xylem and phloem cells, damaging twigs through female oviposition, or by vectoring plant viruses and other diseases. Like cicadas, they produce sound, but this sound is usually not audible to humans. The many species have been placed in some 18 subfamilies. A typical cicadellid from Minnesota; hind tibia showing rows of spines; head, showing position of antenna in relation to eye (on front of head between eyes and head without a carina). Two colorful species from Costa Rica.

Superfamily Fulgoroidea: Diagnostic characters: antennae arising on sides of head beneath eyes, separated from front of head by a vertical carina.
The planthoppers constitute a group of about a dozen families in North America, all recognized by the antennae separated from the front of the head by a vertical carina and thus arising beneath the eyes. They feed on a rather wide range of plant types, but few or of any economic importance. A few exemplary families are listed below:

FYI: Fulgoridae: Diagnostic characters: Anal area of hind with with fine network of crossveins. The family contains many beautiful exotic species: Phrictus ocellatus, a probable lichen mimic, with bright hind wings, Venezuela; Phenax variegatus, Venezuela, notice the wax secretions; Cathedra serratus, Brazil; Fulgora lampetus, Ecuador; F. pyrorhyncha, Malaysia; Zanna terminalis, Malaysia.

Delphacidae: Diagnostic character: Hind tibia showing large, movable apical spur. This is the largest family. Its species are small and often have short wings. One species was a pest on sugarcane in Hawaii.

Flatidae: Diagnostic characters: Forewing with numerous costal crossveins including uniform row of crossveins along front margin; wings held almost vertical at rest, but flatter in some species; clavus (triangular anal area of wing) granular; 2nd segment of hind tarsus with 2 apical spines, one on each side. Very diverse in the tropics. Feed on leaves and and above ground parts of woody/shrubby plants.

FYI: Acanaloniidae: Very similar to Flatidae, but wings are very reticulate, like veins in a leaf, and almost oval, none of the veins line up in even rows; without granules on clavus; hind tibia without spines. All but one North American species are in the genus Acanalonia. Acanalonia bivittata, detail of head showing carina and position of eye, Minnesota.

Issidae: Diagnostic characters: Forewings often shorter than abdomen, if longer, usually oval; without granulation; hind tibiae with spines on apex and on sides.

Derbidae: Diagnostic characters: Terminal segment of beak not more than 1.5 x as long as wide; head often with a projection; often brightly colored, delicate species. Apache dageeri, Minnesota. Derbids feed on woody fungi. Most species are tropical.

Dictyopharidae: Diagnostic characters: Head strongly elongated at front OR frons with 2-3 raised carinae (ridges); terminal segment of beak at least 2x as long as wide. Scolops, Minnesota; two tropical examples, Costa Rica, Venezuela. These feed mainly on grasses. Many have the head produced into a slender process, but some others don't.

Cixiidae: Diagnostic characters: head not extended in front; abdominal terga rectangular; head with median ocellus; terminal segment of beak at least 2x as long as wide. Cixius basalis, Minnesota. Largest family of planthoppers. These are mostly tropical, with some species feeding underground on grass roots.

HETEROPTERA

Mesoveliidae: Diagnostic characters: small, elongate; greenish or yellowish; wingless or winged (if winged, clavus of forewing membranous, membrane veinless); antennae long, slender; tarsal claws apical; ocelli present; legs with conspicuous black spines.
Water treaders, as members of the neustonic fauna, occur on the surface of standing waters, often among floating or emergent vegetation. They feed as scavengers on dead and dying insects trapped in the surface film. Mesovelia mulsanti, winged and apterous adults; hind tibia showing black spines.

Hydrometridae: Diagnostic characters: small, delicate bugs, with very slender, elongate body; head long and slender; eyes bulging in the middle.
Water measurers are also neustonic scavengers and predators, but often go unnoticed because of their very slender bodies. A large adult from Venezuela; detail of head.

Veliidae: Diagnostic characters: small (less than 5 mm), neustonic bugs; tarsal claws anteapical; hind femora extending little, if any, beyond apex of abdomen.
Ripple bugs are commonly found just below the riffles of streams, but also in ponds and lakes. They often occur in large swarms. They prey on other surface dwelling arthropods, detecting their prey through surface vibrations. Rhagovelia obesa, Minnesota.

Gerridae: Diagnostic characters: arger than veliids, also inhabiting the water-surface; tarsal claws anteapical; hind femora extending well beyond apex of abdomen.
Water striders are very common surface bugs in lakes, ponds, and pools. They move across the surface of the water by "rowing" and also communicate by tapping the surface with their legs. They prey on insect trapped or living on the surface. Winged and wingless adults occus in some species. All are freshwater inhabitants except for species in the genus Halobates which occur in the open ocean. Limnoporus dissortis, Minnesota.

Saldidae: Diagnostic characters: small, oval, flattened semiaquatic bugs; forewing membrane with 4-5 long closed cells.
Shore bugs are active shore inhabiting predatory insects. Saldula confluenta, Minnesota.

Belostomatidae: Diagnostic characters: medium to large; brownish, oval, flat, with strong, raptorial forelegs; short, retractile respiratory appendages at tip of abdomen.
Giant water bugs are very common aquatic bugs found in ponds, pools, and ditches. They have a short siphon at the tip of the abdomen used for breathing while they are submerged. They are rapacious predators; the larger species even prey of small fish and frogs. They are good fliers and are attrated to lights at night. They can give a fierce bite if not handled properly. All of these characteristics are captured in their various common names: "fish killers," "toe biters," and "electric light bugs." Lethocerus americanus, a large giant water bug from Minnesota; Belostoma flumineum, Minnesota, male with eggs on dorsum of hemelytra.

Nepidae: Diagnostic characters: slender-elongate or elongate-oval; forelegs slender and raptorial; long, nonretractable breathing tube at tip of the abdomen.
Water scorpions live in the same habitats as giant water bugs and are as equally common. They hang from the surface with the tip of their long siphon exposed and grab passing prey with long raptorial forelegs. Two water scorpions from Minnesota, Ranatra kirkaldyi and Nepa apiculata, representing the two body forms.

Gelastocoridae: Diagnostic characters: small, toad-shaped bugs with bulging eyes.
Toad bugs could not be more aptly named - their resemblance to toads is remarkable. They also hop and can change color to match the substrate! They live along the shores of ponds, lakes and rivers where they prey on other shore inhabiting arthropods. Example: Gelastocoris oculatus (specimen from Kansas).

Corixidae: Diagnostic characters: front tarsi 1-segmented and scoop-shaped; beak very short and hidden, appearing 1-segmented.
Water boatman are very common and abundant in ponds, lakes, pools, and ditches; some species are found in brackish water or in intertidal zones. They use oar-like hind and mid legs for swimming. The mouthparts are adapted for taking in small particles of solid food as well as very small aquatic organisms such as diatoms, protozoans, rotifers and organic material that they sweep into the mouth with the scoop-shaped fore tarsi; others are herbivorous and puncture the cells of filamentous algae while a few prey on mosquito larvae. The males have asymmetrical genitalia and modified pegs on the fore femora for stridulation against the sharp sides of the head. Hesperocorixa laevigata, Minnesota. Head of H. lobata, showing broad, conical beak and modified fore tarsus.

Naucoridae: Diagnostic characters: small, oval, with flattened body, somewhat similar to belostomatids but with front femora greatly enlarged.
Creeping water bugs, or gator fleas, occur in rivers and ponds. Some lotic species are adapted to fast flowing areas, while the lentic species occur among vegeration. They can inflict a very painful bite when handled. They breathe under water by way of a "plastron gill," a region of very dense hairs on the body surface that traps a layer of air across which oxygen and carbon dioxide diffuse. A creeping water bug from Arizona.

Notonectidae: Diagnostic characters: similar to corixids but convex and with front tarsi unmodified; beak more elongate and segmented.
Backswimmers occur in standing waters where they swim upside down in the water column in search of prey, often by sneaking up on them from below. Males also stridulate by rubbing the fore legs against the beak. They also bite! Notonecta insulata, Minnesota.

Pleidae: Diagnostic characters: small (3 mm or less), oval; similar to notonectids, but much smaller, with much more convex body.
Pygmy backswimmers are very common and abundant in weedy ponds in Minnesota, but often go unnoticed because of their small size. They carry a bubble of air on their venral surface for respiration as they crawl around in vegetation in search of their prey, aquatic microarthropods. A pygmy backswimmer from Texas.

Cimicidae: Diagnostic characters: flat, oval, less than 6 mm, wings vestigial.
This is an annoying pest that has become more commonly encountered in recent years, especially in hotels, motels, and apartment buildings. The bugs hide in crack and crevaces during the day. At night they leave their retreats ato feed on unsuspecting guests. They do not vector disease, but cause an irritating bite. Adults can live for several months with out a meal. The common bed bug, Cimex lectularius, Minnesota.

Anthocoridae: Diagnostic characters: small, about 3-5 mm, somewhat oval, flattened, black with white markings; hemelytra with a cuneus; beak 3-segmented.
A minute pirate bug, Minnesota. These tiny bugs commonly occur on flowers and fruit where they feed on insect eggs and small insects. One species, the insidious flower bug, packs a powerful bite for its small size.

Reduviidae: Diagnostic characters: body generally elongate oval, rarely greatly elongate; beak short, 3-segmented, its tip fitting into a stridulatory groove in the prosternum; head elongate with part behind the eyes necklike; transverse groove between the eyes.
The assasin bugs constitute a large, diverse family of highly predaceous bugs; members of the subfamily Triatominae bite humans and other vertebrates for a blood meal. Species of Triatoma, or "kissing bugs," of the Neotropics transmit Chagas' disease, caused by the protozoan Trypanosoma cruzi. The masked hunter is a species that preys on bedbugs. The wheel bug, Arilus cristata, ventral view of head, showing beak and prosternal groove. Several examples of Neotropical species from Costa Rica 1, 2, and Peru 3, 4.

Reduviidae, Phymatinae: Diagnostic characters: front femora greatly thickened; abdomen wider in distal half, extending laterally beyond wings.
Ambush bugs are common, easily recognized, cryptically colored predators, now generally included within the Reduviidae as a subfamily. They are common on goldenrod where the blend in perfectly. They capture other insects, even larger bees, wasps, and flies, that visit flowers during pollination. Phymata pennsylvanica, Minnesota, dorsal and lateral.

Miridae: Diagnostic characters: small,10 mm or less, oval or elongate; hemelytra with cuneus, membrane with 1 or 2 closed cells.
These are very common and abundant bugs found on plants. Most are plant feeders and many of these are of economic importance; others are predaceous. Coquillettia mimetica, adult and ant mimicing nymph, Minnesota. The four-lined plant bug, Poecilopsus lineatus, Minnesota.

Nabidae: Diagnostic characters: elongate, oval; ocelli present; prothoracic legs with femora slightly thickened; membrane of hemelytra with numerous marginal cells.
These predaceous little bugs, the damsel bugs, are important members of the predator community of natural as well as agricutural ecosystems. Nabis americoferus, adult and detail of foreleg.

Tingidae: Diagnostic characters: body and wings with reticulate sculpturing (giving it a "lacey" look).
Lace bugs are known for the remarkable ornamentation of the cuticle of the adult. They are plant feeders and when in great abundance their feeding can can damage plants, especially trees. Corythuca heidemanni, Minnesota.

Aradidae: Diagnostic characters: small, dark, very flat, oval; wings narrow, abdomen extends beyond them.
Another remarkble bug because of its extreme flatness. They occur on and under bark of dead or decaying trees where they feed on fungi. Examples of flat bugs from Peru and Minnesota.

Alydidae: Diagnostic characters: similar to coreidae, but buccula not extenidng past base of antennae; head nearly as wide and as long as pronotum. Broad headed bugs are common and notable because of their noxious smell and the nymphs that resemble ants. They feed on plants. Alydus eurinus, Minnesota. Head of Megalotomus quinquespinosus showing length of buccula in relation to base of antenna.

Coreidae: Diagnostic characters: membrane of hemelytra with many veins; head narrower and shorter than pronotum; scent glands present between middle and hind coxae; hind tibiae sometimes dilated and leaflike; buccula extends back past base of antenna. Not all leaf-footed bugs have expanded hind tibiae, but all have well-developed scent glands. They feed on plants. One species, the squash bug, is a common pest on squash and other cucurbits. Two leaf-footed bugs, Acanthocephalus nr. femorata, Mexico, and Anisoscelis flavolineata, Costa Rica. Head of Euthochthus galeator showing length of buccula in relation to base of antenna.

Rhopalidae: Diagnostic characters: membrane of hemelytra with many veins; usually pale-colored (most specimens in lab collection are black with red margins); 10 mm or less; scent glands absent.
The boxelder bug, Boisea trivittatus, is the most conspicuous member of the family in Minnesota. They feed on the seeds of box elder and aggregate on the sunny, south facing sides of houses in the fall, looking for sites to overwinter.

Berytidae: Diagnostic characters: slender, 5-9 mm; legs and antennae long and slender; last antennal segment short and spindle-shaped.
Stilt bugs are delicate, slender insects. They are largely herbivorous. A stilt bug from Minnesota.

Lygaeidae: Diagnostic characters: scent glands present; membrane of hemelytra with only 4-5 veins.
This is a large and important family of mostly seed feeding bugs. Now, the family has been divided into no less that 10 separate family (see textbook). Many species are important pests of crops, especially grains, while a few others are predaceous. The large milkweed bug, Oncopeltus fasciatus, Minnesota, and scent gland on the thorax of the small milkweed bug, Lygaeus kalmii, Minnesota.

Piesmatidae: Diagnostic characters: Small, about 3 mm, corium and clavus with an irregular network of small cells (pits).
A small family of little bugs most noted for the sculpturing of the wings and thorax. They feed on members of the amaranth plant family. Ash-gray leaf bug, Piesma cinerea, Minnesota.

Pentatomidae: Diagnostic characters: scutellum large and triangular, but not longer than corium and not reaching apex of abdomen; spines weak or absent on tibiae.
Stink bugs are common and well known. They emit odiferous substances from the stink glands. Most are herbivorous, and some are pestiferous, including the harlequin bug on cabbage and the southern green stink bug. A few are predaceous. A large green stink bug from Minnesota, Acrosternum hilare. Two additional Minnesota species, Perillus bioculatus and Brochymena quadripustulata.


Cydnidae
: Diagnostic characters: similar to Pentatomidae but with strong spines on tibiae. These little bugs burrow in the ground or under rocks and wood where they feed on plant roots. They are often attracted to lights at night. A burrower bug from Texas.

Scutelleridae: Diagnostic characters: similar to Pentatomidae, but scutellum extending to apex of abdomen.
These bugs are noteworthy because of the broad extension of the scutellum. Many tropical species are brightly colored. They are plant feeders. Eurygaster alternata, a shield-backed bug, Minnesota. Tectocoris lineola, a striking species from Australia.

Thyreocoridae: Diagnostic characters: similar to Scutelleridae (scutellum covering most of abdomen), but tibiae armed with strong spines and body color shining black. These are intensely black, shiny little bugs. They are common and found on vegetation. Galgupha nitiduloides, Minnesota.