Hymenoptera Family Characters


Tenthridinidae: Diagnostic characters: Antennae threadlike, usually 9 segmented (range 7-10). Forewing with 1 or 2 marginal cells and without intercostal vein. These are very common, often brightly colored sawflies. The mostly predaceous adults are active on flowers and foliage. Most larvae are external leaf feeders, but some are gallers or miners. The family includes the very harmful larch sawfly, Pristiphora erichsonii. Examples: Macremphytus testaceus, a common sawfly from Minnesota. Wings of M. tarsatus, Minnesota. Both species feed on dogwood, Cornus sp.

Cimbicidae: Diagnostic characters: Large bodied, resembling bumble bees. Antennae with 7 or fewer segments and slightly clubbed. Cimbex americana, the elm sawfly, Minnesota. The huge larvae feed on many species of hardwoods, including elm, maple, birch, willow, basswood, etc. Larvae are able to eject a defensive fluid from glands near the spiracles.

Diprionidae: Diagnostic characters: Stout bodied. Antennae with 13 or more segments, usually serrate in female and pectinate in male; forewing with 1 marginal cell. The introduced pine sawfly, Minnesota, Diprion similis, male and female, and wings. Larvae feed on many species of pines and cause economic damage.

Siricidae: Diagnostic characters: Rather large insects. Female with 2 long, slender structures at tip of abdomen. Pronotum (in dorsal view) wider than long, and narrower at the middle than laterally. A large female horntail, Tremex columba, from Minnesota (photo by Jeff Hahn, University of Minnesota) and detail of abdomen showing ovipositor and "horn." Larvae feed as wood borers in maple, beech, oak, and other hardwoods, usually on dead or dying trees. They have been established beyond their native range by transport through the lumber and wood industry.


Braconidae: Diagnostic characters: Like ichneumonds in general appearance, but usually smaller and with shorter abdomen. 1 recurrent m-cu cross vein or m-cu cross vein absent (2nd recurrent vein always
absent). Two species from Minnesota, Cardiochiles viator and Macrocentrus marginator; an endoparasite of Lepidoptera larvae; braconid wing venation. Braconid biology is very diverse and the family includes parasites of Lepidoptera larvae and eggs, wood boring beetle larvae, sawflies, flies, aphids, bugs, and many other orders of holometabolous insects.

Ichneumonidae: Diagnostic characters: "Horsehead" cell in forewing; 2 recurrent m-cu cross veins present. Antennae long, usually 16 or more segments. This is a hugely diverse family, perhaps the largest family of insects. The morphological, as well as host diversity and biology, is very large and should not be judged by the few examples given here. Enicospilus purgatus, Minnesota, an endoparasite of Lepidoptera larvae; ichneumonid wing venation (Netelia ocellata, Minnesota, an endoparasite of cutworms).

Pteromalidae: Diagnostic characters: See Dr. John Luhman's summary sheet.

Eulophidae: Diagnostic characters: See Dr. John Luhman's summary sheet.

Encyrtidae: Diagnostic characters: See Dr. John Luhman's summary sheet.

Eurytomidae: Diagnostic characters: See Dr. John Luhman's summary sheet.

Chalcididae: Diagnostic characters: All are small (less than 4 or 5 mm). Hind femora greatly enlarged. Venation greatly reduced (no closed cells in forewing). Usually black and yellow, never metallic. (And see Dr. John Luhman's summary sheet). Conura nigricornis and detail of hind leg and wing venation. Chalcids parasitize Lepidoptera, Coleoptera, and Diptera; some are hyperparasites (parasites of parasites) of Tachinidae (Diptera) and Ichneumonidae.

Cynipidae: Diagnostic characters: Antennae slender. Wing venation reduced, but not as greatly as in chalcidoids. Abdomen usually oval and shining. Scutellum often oval, elevated. A gall wasp from Minnesota and wing venation. Gall wasps are gall makers or live in the galls of other gall making insects, mostly on oaks or Rosaceae. They have very complex life cycles including parthenogenesis, alternation of sexual and asexual generations, multiple host plants, etc. Alfred C. Kinsey, best known for his work on human sexuality, began his scientific career working on gall wasps and amassed a hugh collection and significal body of work on this family of insects.

Evaniidae: Diagnostic characters: Small abdomen carried like a flag on slender stalk high above coxae (hence common name for the group). Hyptia harpiodes, Minnesota, parasitic on wood roach (Parcoblatta) egg cases (all ensign wasps are parasitic on cockroach egg cases). This is the northern most species in the family in North America.

Gasteruptiidae: Diagnostic characters: Similar to ichneumonids, but head attached by slender neck. Antennae short. Abdomen attached high above hund coxae. Only one recurrent vein in wing. Hind tibiae may be enlarged. A male Gasteruption floridanum. The female is very similar, but with a very long, slender ovipositor. Larvae are predators or predator-inqulines in the nests of solitary bees or wood nesting Sphecidae.

Pelecinidae: Diagnostic characters: Shiny black wasps. Females with very long abdomen; males have shorter, cylindrical abdomen, but are rarely encountered. Pelecinus polyturator, female and male. This is a very widespread species which occurs from Canada into southern South America. In Minnesota, the larvae are parasites of June beetles, Phyllophaga spp., family Scarabaeidae.


Chrysididae: Diagnostic characters: Green or blue-green with pitted thorax. 4-segmented abdomen is concave ventrally; do not sting. Cuckoo wasp larvae are ectoparasites of bee and wasp larvae, although some feed on walkingstick eggs. A cuckoo wasp, Chrysis nitidula, from Minnesota. This species parasitizes vespid wasps that nest in cavities in stems, borings in wood, or abandoned mud cells.

Tiphiidae: Diagnostic characters: Usually black and somewhat hairy. Most have two platelike lobes that extend from the mesosternum over the bases of the middle coxae. Myzium maculata from Minnesota, a parasite of soil inhabiting scarab beetle larvae. View of mesosternum showing platelike lobes. Another species has been imported as a biological control agent of the Japanese beetle.

Scoliidae: Diagnostic characters: Large, hairy. Wing membrane of forewing with numerous wrinkles at apex. May have notch on anterior margin of eye. A large colorful scoliid from Florida, Campsomaris quadrinotatus, an ectoparasite of scarab grubs living in soil. Apex of forewing showing wrinkles. Females burrow in the ground to sting and paralyze a host grub.

Mutillidae: Diagnostic characters: Antlike in appearance. Very hairy and generally brightly colored. Females wingless and males winged. Antennae not elbowed. A female and male of Dasymutilla occidentalis. These specimens are from Louisiana and Florida. The species is a parasite of the bumble bee Bombus fraternus. Most species are ectoparasites of bee and wasp immatures. Females can inflict a painful sting. In the US, they are diverse in the south and arid southwest. Prof. C.E. Mickel, University of Minnesota, was an expert in the group and amassed a large and important collection of mutillids in the university's collection, including many type specimens.

Formicidae: Diagnostic characters: First or first and second abdominal segments node-like or with hump. Antennae of females are elbowed; first segment is long. This is a large, dominant, extremely diverse family of eusocial insects. Their biologies, societies, habitats, diets, etc. are diverse and often complex. The book by Holldobler and Wilson, The Ants, (1990) is the primary reference for the group. A large ant from Brazil.

Pompilidae: Diagnostic characters: Characteristic transverse suture across the mesopleuron. Usually long-legged. Pepsis sp., a huge spider wasp from Brazil that parasitizes tarantulas. Detail of mesopleural sulcus of an undetermined spider wasp from Brazil. Larvae of most species feed on spiders which are captured and paralyzed by the female.

Vespidae: Diagnostic characters: Long first discoidal cell. Wings folded longitudinally (at rest). Eye sometimes notched. The family includes some eusocial species (hornets, paper wasps, yellow jackets, for example), but many others, like the potter wasps, are solitary (not social). Both the social and solitary species feed the larvae or provision the nest with insect prey (or with pollen and nectar in some groups). The bald faced hornet, Vespa maculata, from Minnesota, and detail of face showing notched eye. The eastern yellowjacket, Vespa maculifrons, Minnesota. Vespid forewing showing very long 1M or 1st discoidal cell.

Sphecidae: Diagnostic characters: Often difficult to characterize because of very diverse size, shape and color -- some are threadwaisted and others are vespid-like, but all have pronotum that is short and collar-like, with posteriorly directed rounded lobe. These are solitary wasps (a few rare examples of eusocial species are known) in which the females hunt for arthropod prey to feed the larvae, which are in concealed cavities, mud nests, burrows, hollow plant stems, etc. Examples of a number of species of sphecid wasps: Ammophila harti, Minnesota, preys of hairless lepidoptera larvae. Bembix americana, a sand wasp, Minnesota, preys on syrphids, tachinids, sarcophagids, calliphorids, muscids and other flies. Sphecius speciosa, the cicada killer, Oklahoma, and detail of its pronotum. Chlorion cyaneum, Nebraska, and detail of its pronotum; preys on Gryllidae.

Crabronidae: Diagnostic characters:

APOIDEA: Bees are closely related to the sphecid/crabronid wasps. Both have rounded lobes on the pronutum. Sphecids have the body sparsely haired, and the hairs are not plumose. In addition, the hind basitarsus is similar in size and appearence to the other tarsal segments. In bees, the hind basitarsus is large and flattened and the body is usually densely covered with plumose hairs (the parasitic bees are not very hairy, but still have the modified hind basitarsus).

Halictidae: Diagnostic characters: Usually brilliant bronze or green bees, but many are blackish. Basal vein is strongly arched. This is a large, diverse family. They nest is burrows in the ground. Many species, especially in the genus Nomia, are economically important plant pollinatiors. Some Lasioglossum species, the sweat bees, are attracted to human and animal perspiration. The family contains solitary as well as primitively eusocial species; a few are kleptoparasites on other bees. A beautiful metallic green species from Minnesota, Halictus sericeus. Female and male abdomen and wing venation (forewing, hind wing).

Andrenidae: Wing venation of Andrena wilkela, Minnesota, showing jugal and vanal lobes of hind wing in relation to submedian cell. These are also ground nesters. Most are solitary. The genus Andrena is very common in the spring.

Colletidae: The plasterer bees (Colletinae) burrow to nest in the ground and line their burrows with a thin, clear plaster. The very common yellowfaced bees (Hylaeinae) resemble small wasps and carry pollen in their crops rather than on the legs. A yellowfaced bee from Minnesota, Hylaeus ziziae, and detail of face.

Megachilidae: Diagnostic characters: Two submarginal cells of about equal length on FW. Workers carry pollen under abdomen (where they have long hairs). Mandibles adapted for cutting. These bees line the cells of their nests with cut pieces of leaves. Most species are solitary. A leaf cutter bee from Minnesota, Magachile latimanus, female, male, and wing venation.

Apidae: Diagnostic characters: Forewing with 3 submarginal cells. Galeae and glossa ("tongue") long and slender. Jugal lobe in hind wing short or lacking.

Apinae, Apini: In Minnesota includes only the honey bee, Apis melifera, native to the Old World.

Apinae, Bombini: bumble bees, e.g., a large Minnesota species, Bombus impatiens; wing venation;

Apinae, Anthophorini: digger bees, e.g., Anthophora terminalis, wings and hind leg;

FYI: Apinae, Euglossini: orchid bees, e.g., a large orchid bee from Venezuela, Eufriesia sp.

Nomadinae: Nomada sp., a cuckoo bee, from Nebraska. These wasp-like, hairless bees all are parasites in nests of other bees. They do not transport pollen and thus lack pollen carrying structures.

Xylocopinae: A very large carpenter bee, Xylocopa sp., from Brazil. These also occur in North America and excavate large galleries in wood. Other, smaller carpenter bees (Ceratina) burrow in the pith of plant stems.