Review Sheet -- Test 2 (Week 8) Biology 1224 -- Entomology; James Adams
Infraclass Neoptera; Division Endopterygota
Superorder Mecopteroidea --
Mecopteroid Orders (Chapter 15, page 318; Chapters 41-45)
The most generalized in body plan in these orders are the Mecoptera. Two distinctly
closely related pairs of orders are also included here -- the Diptera and Siphonaptera, and the
Lepidoptera and Trichoptera. Obvious hypognathous mouthparts are shared among all orders.
Order Mecoptera --
The Scorpionflies and Hangingflies (Chapter 41)
Moderately sized insects; elongate body and head, with distinctly elongated hypognathous
maxillae/mandibles; mouthparts serrated on end. Meso-/metathorax fused; wings narrow and
elongate with numerous crossveins; there are several species that have reduced wings or lack
wings completely. Short (1 to 2 segmented) cerci on elongate abdomen.
Larvae caterpillar-like (or grublike), with sclerotized head; mandibulate mouthparts and
compound eyes. Thorax with short legs that have tibia and tarsi fused, with a single claw.
Abdomen typically with prolegs on segments 1-8, and segment 10 with hook or suction pad.
Pupae are dectitious and exarate, but virtually non-motile; and pupation occurs in a cell in the
soil, litter, or in decaying wood (no cocoon).
Adults are in some ways similar to Neuroptera and Megaloptera; however, larval form and
mouthpart structure suggest relationships with the other mecopteroid orders, particularly
Diptera. These insects typically prefer moist, forested habitats in the east, or are active only
during the moist times of the year. Mating may last several hours. Fossils of this group are very
old, with an incredibly diverse fauna that is very reduced today.
About 500 species worldwide, mostly in two families: the Panorpidae (Common
Scorpionflies) and Bittacidae (Hangingflies) -- you need to be familiar with both. Both of these
families can be somewhat frequently encountered in GA. One other rare species Merope tuber
(Meropeidae) can be found in GA.
Panorpidae have the cerci/end of abdomen swollen (the genital bulb) and curled upward in
males (scorpion-like). Adults are typically scavengers on dead insects/snails, and are good at
stealing meals from spider webs.
Hangingflies are predatory, and catch prey as a nuptial gift as well, carrying the prey in the
hindlegs and hanging with the forelegs. Females scatter eggs on the soil. Might be confused with
various crane fly families, but remember, hangingflies have four wings!
Order Diptera ("two wings") -- the Flies (Chapter 42)
Very tiny to moderate-sized; typified by having functional wings only on the mesothorax;
wings on the metathorax modified into halteres (vibrating gyroscopic balancing organs). Head
with large compound eyes; mouthparts quite variable among families, but often modified into a
proboscis for drinking; the gut often has a crop (an enlarged region for storage). Prothorax
reduced to a collar and fused to the mesothorax, which is large and divided by sutures (scutum,
scutellum); metathorax also reduced. The abdomen is narrow and streamlined in most groups, for
fast flight; the male genitalia are often rotated (termed torsion) from the typical position in other
insects. Egg-laying is typically singly or in small groups near the larval food.
Larvae maggot-like or wormlike (without legs), and mostly lacking antennae/eyes. Larvae
are typically found in moist or aquatic environments. A number are internal parasites of animals.
Number of spiracles is variable, mostly based on larval substrate, and may be absent in aquatics.
Pupae adectitious, obtect (Nematocera, Orthorrapha), with many Nematocera spinning
cocoons around the pupa, or exarate in puparium (hardened last larval skin; Cyclorrapha); most
are virtually non-motile, but change rapidly into the adult stage.
Most species develop rapidly (with short lifespans), with several generations a year. Life
styles of flies are incredibly varied, with parasites, predators and nectar feeders, but the majority
are saprophytic, feeding on decaying vegetable or animal products. There are few adult
herbivorous flies, though several larvae feed on plants and may stimulate gall formation.
Several families are of economic importance, mostly as vectors of disease both of humans
and domestic animals, such as malaria, yellow fever, encephalitis, dysentery, sleeping sickness,
etc. Only a few damage plants (fruit flies), and are rarely of major impact.
This is the fourth largest order of insects, with 85,000 identified and likely over 150,000
Suborders (that you are likely to encounter):
Nematocera -- filiform antennae, typically longer than thorax; pleural suture straight;
larval head sclerotized, with horizontally oriented mandibles for biting.
Likely encountered families in the Nematocera include:
*Tipulidae & Pediciidae (and others): Crane Flies; long legs
Ptychopteridae: Phantom Crane flies; alternating white and black legs, often hang
by forelegs from vegetation.
*Psychodidae: Moth Flies; hairy, with rounded wings, often found in houses around
drains, where larvae feed on moist "drain goo".
Chironomidae: Midges (several other families similar)
*Bibionidae: March Flies (or Love Bugs); often black with orange thoraces
Mycetophilidae: Fungus gnats; common in households; larvae in soil around plants
There are a few other "gnat-like" families that are common. Some other families in the
Nematocera include very small species that bite humans (Biting Midges, Blackflies).
Brachycera -- short bristle-like antennae (aristae); pleural suture with two distinct turns;
larval head unsclerotized with retractable, vertically oriented mandibles and obtect pupa (division
Orthorrapha), or mandibles lacking and pupa exarate in puparium (division Cyclorrapha -- this
division is now often further divided into Calyptratae and Acalyptratae).
Likely encountered families in the Brachycera include:
*Stratiomyidae: Soldier Flies; elongate, somewhat bulbous terminal antennal seg.
*Tabanidae: Horse and Deer Flies; large and biting.
Rhagionidae: Snipe Flies; common species here is black, with orange fuzzy thorax.
Acroceridae: Small Headed Flies; distinctive small head; larvae parasitic on spiders
*Asilidae: Robber Flies; typically large active insect predators; wings folded at rest.
*Mydidae: Mydas Flies; also large, insect predators; hold wings out to sides.
*Bombyliidae: Bee flies; hairy, rounded, with long sucking mouthparts for nectar.
Dolichopodidae: Long-legged Flies; small, shiny, run around on leaf surfaces.
*Syrphidae: Syrphid flies; many are bee mimics.
Conopidae: Thick (Large)-headed flies; many "narrow-waisted" like some wasps
Ulidiidae (fomerly Otitidae): Picture-winged Flies; hold wings flat out to sides; walk
and wave wings.
Tephritidae: (Large) Fruit Flies; similar to otitids.
Schiomyzidae: Marsh Flies; tan or yellowish; spotted wings; larvae mollusc parasites
Drosophilidae: Pomace or Small Fruit Flies; very common in households on fruit.
*Muscidae: House Flies (though most don't live in houses!)
Oestridae: Bot Flies; larvae parasitic on large (domestic) mammals.
*Tachinidae: Tachinid Flies; robust, with rounded hairy abdomens; larvae typically
parasitize other insects (so can be beneficial in pest control).
*Calliphoridae: Blow and Bottle Flies; many metallic blue or green; most "maggots"
Sarcophagidae: Flesh Flies; similar to muscids and calliphorids.
Be aware that there are a large number of other families of flies that include very small
species; I've presented most of those that are common and that you can "stick a pin through".
Order Siphonaptera -- The Fleas (Chapter 43)
Parasitic; small, wingless, and flattened laterally (tall and skinny) for moving in between
hairs on hosts. Hypognathous head; ocelli only; mouthparts (lips/maxillae) long and blade-like
and aligned for sucking (but no mandibles); mostly blood feeders as adults. Legs with large
coxae, particularly the hindlegs (for hopping). Larva with head capsule but without legs, similar
to some flies; most larvae not on host, but in "nest". Pupa adectitious and exarate in light cocoon.
Egg production several hundred to a thousand; larval development rapid under favorable
conditions, where nest has plenty of organic debris. Pupal eclosion frequently stimulated by
mechanical disturbance (presence of host).
Adults vary in host specificity; some are host specific, others occur on as many as 35
different host species. Some host species may host upwards of 20 flea species.
2400 species, with most species on mammals and a few on birds (including domestics).
Though nine families are in the U.S., nearly all common species are in the family *Pulicidae.
Order Trichoptera ("hairy wings") --
The Caddisflies (Chapter 45)
Small to moderately large; body long and slender. Head with large compound eyes; often
very long antennae; hypognathous, with mandibles reduced and maxillae simple. Prothorax
reduced and collarlike (like dipterans); wings with numerous hairs and few crossveins; wings held
roof-like over the body (like many moths); long legs (long coxae). Larvae mostly caterpillar-like
and aquatic, many constructing a family-distinctive case around them from silk and environmental
materials; others build net-like webs; larvae with strongly developed mouthparts and short
antennae; hook shaped prolegs on terminal abdominal segment (for anchoring). Pupae are
dectitious, exarate and pupation is in the larval case in water.
Most adults apparently don't feed (short life); most are nocturnal and come to lights.
Mating occurs in air or on vegetation, sometimes in swarms; eggs are deposited on vegetation
overhanging water (similar to most species with aquatic larvae). Larvae of free-swimming and
net-building species predaceous; larvae of case-makers are probably scavengers. Larvae
respond to very specific conditions, and therefore are decent water quality indicators.
7000 species, with 1200 in N. America; most are shades of brown or gray, only
occasionally with patterned wings. Identification of adults is often much more difficult than
identification of particularly the case-making larvae (see Table 45.1, pages 566 and 567).
Frequently encountered families in GA include: Hydropsychidae, Hydroptilidae,
Phryganeidae, Limnophilidae, Lepidostomatidae, Brachycentridae, Glossosomatidae,
Molannidae (in spring seeps), Philopotamidae, Polycentropodidae, Rhyacophilidae