Review Sheet -- Test 2 (Week 9) Biology 1224 -- Entomology; James Adams
Infraclass Neoptera; Division Endopterygota
Superorder Hymenopteroidea: Chapter 15, page 213; Chapter 46
One order is included in this superorder -- the Hymenoptera. Considered to be quite
distinct from all other endopterygotes: they have numerous Malpighian Tubules (unlike the 4 to 6
in all other endopterygotes); wing venation is very different, with lots of fusions and several large
cells. They are probably most closely related to the Mecopteroids, as there are several
hymenopteran families that have caterpillar-like larvae similar to the Mecoptera and Lepidoptera,
and some also have pupae enclosed in a cocoon.
Order Hymenoptera ("membrane-winged")
-The Bees, Wasps, Ants, Sawflies, etc. (Chapter 46)
Minute to large insects, usually with membranous wings, though many ants wingless.
Head typically hypognathous, with mandibles adapted for chewing; labium often elongated
(sometimes extremely) and aids in drinking (nectar); antennae typically obvious and sometimes
quite long and filiform. Prothorax small and collarlike, though larger in ambulatory species (ants);
mesothorax large and fused with smaller metathorax; wings membranous, almost always with
clear areas and with several cells; veins often fused/reduced in number, and small species with
small wings often practically veinless; wing coupling by hamuli (hooked setae on leading edge of
hindwings). Primitive families (Symphyta) with abdomen relatively unmodified; in more advanced
families, abdomen with first segment (propodeum) fused to metathorax; second segment typically
narrowed into a petiole (stem) for increased flexibility; rest of abdomen enlarged. Females
typically with slicing or piercing ovipositor for laying eggs in plant stems or in animal tissues
(larvae); modified into a stinger in many advanced families (males DON'T sting). The stinger
venomizes prey for immobilization, but may be used in defense against vertebrate predators,
particularly in social species, and the venom produces significant pain in vertebrates. As such,
many species are warningly colored.
Larva very caterpillar like, with several pairs of abdominal prolegs, in free-living forms;
more grublike or maggotlike in internal plant feeding and in nest-building (caregiving) species,
such as in the Apocrita. Larvae of Apocrita do not have the midgut connected to the hindgut;
they are fed by adults a very nutritious soup that is mostly absorbed; avoids contamination of the
nest with fecal matter; the gut completes development in the last larval instar, and the gut is
voided before pupation. In parasitoid species, first instar is often well developed, but head
capsule and legs become reduced after infesting host. Pupa is adecticious, but usually exarate,
often enclosed in a cocoon.
Mating may be in the air, or on some surface, frequently where the females are visiting for
food. In social species, females (queens) can often control the sex of the offspring by storing
sperm in her spermatheca, and may be able to make sterile stinging females (workers in social
species) and haploid males for when mating is necessary to produce another generation. A few
species of wasps are entirely parthenogenetic, exclusively producing females.
The Hymenoptera includes a lot of beneficial species, such as pollinators and predators on
a number of herbivorous insects. Additionally, a number of species are parasitoids on larvae of a
huge number of species in different orders, including some very obnoxious hymenopteran species
as well (such as Fire Ants). Some species are even hyperparasitoids. As such, these species
have been used for biological control. The Honeybee is useful not only as a pollinator, but for its
honey and wax. There are some damaging species (gall wasps, sawflies) and nuisance species
(stinging species of bees, wasps, ants), though beneficial species outnumber destructive ones.
Many species social, though there are a lot of solitary nest builders as well.
Number of Hymenoptera likely somewhat less than the 250,000+ Lepidoptera, but the
small parasitoid species of Hymenoptera may bring the number of Hymenoptera in excess of
Symphyta -- Abdomen not narrowed at thorax.
Likely encountered subfamilies in the Symphyta include:
Tenthredinidae, Cimbicidae, Diprionidae (and others): Sawflies
Apocrita -- Abdomen distinctly narrowed at thorax, having the appearance of a "waist".
Likely encountered families in the Apocrita include:
*Ichneumonidae: Ichneumon Wasps; parasitoids, typically with long ovipositors.
Braconidae: Smaller but similar to Ichneumons
Evaniidae: Evaniid or Ensign wasps; larvae parasites on cockroach oothecae.
Gasteruptiidae: Adults on flowers, larvae parasites on other wasp larvae.
Cynipidae: Gall wasps and others; most likely to encounter the (fuzzy) galls.
Chalcididae: Chalcidid wasps; small parasites, often with bizarre body shape
Leucospididae: Larger than preceding; parasites resembling small yellow jackets
Pteromalidae: Small, but commonest of the chalcidoid families
*Chrysididae: Cuckoo Wasps; relatively small but stunningly colored insects;
parasites on other wasps and bees; females do not sting, but roll into a ball when
held; larvae parasites on beetle larvae
Tephiidae: Tephiid wasps; often large with elongated, striped, hairy abdomen
*Scoliidae: Similar to tephiids; our commonest is black with orange abdominal end
*Mutilidae: Velvet Ants; also hairy; wingless females; stinger is extremely long
Pompiliidae: Spider Wasps; sometimes very large (such as the Tarantula Hawk)
*Vespidae: Potter Wasps, Yellow Jackets, Hornets, Paper Wasps and others; some
of the most familiar wasps; some are social
*Sphecidae: Mud Daubers, Thread-waisted Wasps, Sand Wasps, and others; all
species solitary; many elongate species but some much more stout
(Bees: superfamily Apoidea)
Colletidae: Yellow Faced and Plasterer Bees; typically with light colored fuzzy frons
Andrenidae: robust bees; dark-striped or darkish colored bees
*Halictidae: Many dark colored, but small gold or green bees are these.
*Megachilidae: Leaf Cutter Bees; robust bees; hold wings out while visiting flowers
Anthophoridae: Digger Bees, Cuckoo Bees; Diggers large and robust, ground
dwelling; Cuckoos lay eggs in other hymenopteran nests, and larvae eat the other
species brood. This family frequently included in the Apidae as a subfamily
*Apidae: Carpenter Bees, Bumblebees, Honeybees
As was the case with the Diptera, be aware that there are a number of other families that
contain minute species, so small that some lay eggs inside eggs of other small hymenopterans.