Introduction to the Insect Orders

The following order information and list of exemplary links for each order was developed by high school students working as part of the Bugscope Operations Team.


Order Dermaptera (Derma=skin, ptera=wings) - Earwigs

Commonly called earwigs, these insects' most prominent feature is the forcepslike cerci. They may or may not have wings. If they do, the front wings are short, leathery and veinless while the hind wings are membranous and rounded. Earwigs have chewing mouthparts and undergo simple metamorphosis. Earwigs eat dead and decaying vegetation, living plants, and occasionally other animals. They are mostly nocturnal. Of the winged variety, some are good fliers while others only fly when forced. Eggs are laid in burrows or under debris and guarded by the mother. A few species have glands on the dorsal side that emit a foul -smelling fluid as a defense mechanism.

Links:
Dermaptera http://phylogeny.arizona.edu/tree/eukaryotes/animals/arthropoda/hexapoda/dermaptera/dermaptera.html#TOC4
Dermaptera http://www.gypsymoth.ento.vt.edu/~ravlin/insect_orders/dermaptera.html
Order Dermaptera (Earwigs or Pincerbugs), Insects of the San Francisco Bay Area, University of California, Berkeley
http://www.cnr.berkeley.edu/explore/Taxa/Dermaptera/OrderDermapteraPage.htm
Dermaptera http://www.cals.ncsu.edu/course/ent425/compendium/earwigs.html
Dermaptera http://home.stny.lrun.com/science/biology/Entomology/Dermaptera.html


Order Embioptera (Embio=lively, ptera = wings) - Webspinners

Their common name is webspinners and unlike most silk-producing insects, the silk glands and spinnerets are located in the front two feet, not in the mouth.
they have somewhat flattened bodies and are between 4 and 7 mm long. Webspinners have chewing mouthparts and undergo simple metamorphosis. The legs are short and stout. Most males are winged but some have vestigial wings or no wings at all. The front pair of wings is quite similar to the hind pair. Females are always wingless. Strangely enough, within one species there may be winged as well as wingless males. Webspinners have 10 segmented abdomens with two-segmented cerci on them. Some males have only one segment on the left cercus. One species is known to be parthenogenetic (able to reproduce asexually). Webspinners live in self-spun silk homes in debris, cracks in the soil, under rocks, or under bark and among plants. Most species are social and live in colonies. All young are able to spin silk as they grow up.. Large and cylindrical and laid in the silken homes where they are watched by females. As a defense mechanism, webspinners may feign death or run backward rapidly. They feed on various plant materials.

Links:
Gordon's Embioptera Page http://www.insect-world.com/main/embiop.html
Embioptera http://www.cals.ncsu.edu/course/ent425/compendium/webspi~1.html
Embiidina http://www.ag.arizona.edu/ENTO/tree/eukaryotes/animals/arthropoda/hexapoda/embiidina/embiidina.html


Order Isoptera (Iso=equal ptera=wing) - Termites

Termites, as Isopterans are commonly called, live in social groups and have a highly advanced caste system. In one colony there may be winged or wingless individuals, depending on caste. Winged individuals have two pairs of membranous wings that are almost identical in size and venation, hence the name Isoptera. They have chewing mouthparts and undergo simple metamorphosis. Termites are similar to ants in superficial appearance and social structure but there are some important differences. Termites are lighter colored and have softer bodies than ants. Ant's hind wings are smaller than their front; termite's wings are the same size. The termite cast system has moth sexes as workers and soldiers, with all nymphs as workers and ants these positions are fulfilled by adult females only. Termites appear similar to cockroaches and are sometimes placed in the same as them. One species carries its eggs in a structure that closely resembles a cockroach's ootheca. Termites often groom each other, probably because of pheromones. Besides their well known diet of wood, they eat the cast skins and feces of other termites, and dead termites.

These insects live in moist underground colonies or dry aboveground habitats. Some African species make nests up to 9 meters (30 ft) high. Dry wood termites, who live without contact to moist soil, obtain all their water from the oxidation of food, the waste water from respiration. Termites digest the cellulose in wood with the help of flagellated protozoa or bacteria which live in their digestive tracts. If these helper organisms are removed, the termite will eventually starve to death. In order to transport these micro-organisms to their young, termites undergo a unique process called trophallaxis. Trophallaxis involves the transfer of liquids from the anus of one termite to the mouth of the other.

Links:
Dr Don's Bizarre Termite Page http://www.labyrinth.net.au/~dewart/bizarre.htm
Termites http://www.orkin.com/termites/termitesindex.html
Termite diversity and its role in tropical ecosystems http://www.nhm.ac.uk/science/entom/project3/index.html
Isoptera http://www.cals.ncsu.edu/course/ent425/compendium/termites.html


Order Zoraptera (Zor=pure aptera=wingless) - Zorapterans

These tiny insects (3 mm) are similar to termites in appearance. Both sexes may be winged or wingless. The hind wings are smaller than the front. Adults eventually shed their wings, as in termites and ants. Wingless forms also lack any eye structures while winged forms have compound eyes and three ocelli. Zorapterans have 10-segmented abdomen. They have chewing mouthparts and undergo simple metamorphosis. This order contains only one family, Zorotypidae, and one genus, Zorotypus. There are 22 known species in this genus. Colonies may be found under bark and in rotting logs. Zorapterans eat fungus spores and small dead arthropods.

Links:
Zoraptera http://128.196.42.70/tree/eukaryotes/animals/arthropoda/hexapoda/zoraptera/zoraptera.html
Gordon's Zoraptera Page http://www.insect-world.com/main/zorapter.html
Zoraptera http://www.cals.ncsu.edu/course/ent425/compendium/zorapt.html
Zoraptera http://www.gypsymoth.ento.vt.edu/~ravlin/insect_orders/zoraptera.html


Order Psocoptera (Psoco=rub small, ptera=wings) - Psocids

These small (6 mm) soft-bodied insects may be winged or wingless. They have four wings with the hind pair smaller (and rarely vestigial). The antennae are fairly long and there are no cerci. Psocids, often called book lice, have mandibular mouth parts and simple metamorphosis.
Psocids feed on molds, fungi, cereals, pollen, fragments of dead insects, and similar materials. They lay eggs singly or in clusters and sometimes cover them with silk or debris. Some species are gregarious and construct webs.

Links:
Booklice http://www.blackpool.net/www/sbwalsh/booklice.htm
BOOKLICE http://entowww.tamu.edu/extension/bulletins/uc/uc-010.html
Psocoptera booklice http://www.inscyclo.com/order/psocoptera.htm
Booklice http://www.ext.vt.edu/departments/entomology/factsheets/booklice.html


Order Grylloblattodea (Gryll=cricket, blatta=cockroach) - Rock Crawlers or Icebugs

Commonly called rock crawlers or icebugs, Grylloblattids are slim, long, and yellowish brown or grayish. They have no wings and have long antennae.
Females possess a sword shaped ovipositor. They have chewing mouthparts and undergo hemimetabolous development. Rock Crawlers live in mountains and high altitudes, under rocks, logs and debris. They also live in snow fields, ice caves and other low temperature habitats. They are omnivorous and usually nocturnal.

Links:
Gordon's Grylloblatodea Page http://www.insect-world.com/main/gryllobl.html
Grylloblattodea http://www.cals.ncsu.edu/course/ent425/compendium/rockcrwl.html
Grylloblattodea http://ag.arizona.edu/tree/eukaryotes/animals/arthropoda/hexapoda/grylloblattodea/grylloblattodea.html#TOC4


Order Mallophaga (Mallo=wool, phaga=eat) - Chewing Lice

These wingless parasites are often called chewing lice. Because they prey on birds and mammals, they are often also called bird lice. They have small compound eyes and no ocelli. Chewing lice have chewing mouthparts and undergo hemimetabolous development. They are major pests of many domestic animals, especially poultry. They cause skin irritation, emaciation and exhaustion of the host. The host may then be killed by the lice or by a secondary infection.

Mallophaga species are very particular in their host selection. A few may have no more than six hosts, however. They feed on bits of hair, feathers or skin of the host. They do not appear to use humans as a host. Females secure up to 100 eggs on the hair or feathers of the host. Chewing lice get to one host to another by contact between hosts, as in a nest. They will soon die without a host.

Links:
The Biting Lice http://www.insect-world.com/main/mallopha.html
Phthiraptera http://www.life.uiuc.edu/Entomology/insecthtmls/pthiraptera.html
Phthiraptera http://www.gypsymoth.ento.vt.edu/~ravlin/insect_orders/phthiraptera.html
Mallophaga http://www.biology.ualberta.ca/courses.hp/zool352/text/index/insec08i.htm


Order Anoplura (Anopl=unarmed, ura=tail) - Sucking Lice

These parasites are called sucking lice. Unlike mallophaga, they have sucking mouthparts and are parasites of only mammals and not birds. They are wingless and may be eyeless. The mouthparts consist of three piercing stylets that are retracted into a cavity in the head when not in use. The tarsi (feet) of anoplurans consist of a large claw and a process that acts like a thumb. This setup allows the sucking lice to cling to its host's hairs. Anoplurans undergo hemitabolous development.

Sucking lice are extremely specific in their hosts. They infect many mammals including humans. "Cooties" are a representative species of this order, as are head lice. Females lay eggs similarly to Mallphaga, by attatching them to hairs or clothing fibers. Sucking lice may cause skin irritation and they spread certain diseases.

Links:
A different Tempo of Evolution in Birds and their Parasitic Lice http://taxonomy.zoology.gla.ac.uk/rod/posters/swifts.html
Lice http://www.ent.iastate.edu/imagegal/phthiraptera
Phthiraptera http://www.inscyclo.com/order/phthiraptera.htm
Introduction to the Phthiraptera http://www.ucmp.berkeley.edu/arthropoda/uniramia/phthiraptera.html
Anoplura http://taxonomy.zoology.gla.ac.uk/ToL/Phthiraptera/anoplura.html


Order Thysanoptera (Tysano=fringe, ptera=wing) - Thrips

Thrips, as thysanopterans are commonly called, are lender and may be winged or wingless. When they have wings, they have four and the wings have a fringe of hairs on them. Thrips have sucking mouthparts. Some thrips have ovipositors. Thrips can undergo parthenogenesis and some species are not known to have male members. Thrips undergo a kind of intermediate form of development: there are two larval stages followed by two to three inactive pupal stages. This resembles hemimetabolous development in that preadults have external wings but resembles holometabolous development in that there is a pupal stage and some wing development is internal.

Thrips use their sucking mouthparts to feed on plant juices and those with ovipositors use them to lay eggs in plant tissue. Those that do not lay eggs on or under bark or flower parts. Because of these habits, many thrips are considered pests. They destroy plant cells and may spread disease. A few thrips eat fungus spores, some eat small arthropods and a very few may bite humans.

Links:
Introduction to the Thysanoptera http://www.ucmp.berkeley.edu/arthropoda/uniramia/thysanoptera.html
Thysanoptera http://phylogeny.arizona.edu/tree/eukaryotes/animals/arthropoda/hexapoda/thysanoptera/thysanoptera.html
THRIPS http://www.ag.usask.ca/cofa/departments/hort/hortinfo/pests/thrips.html
Thrips Index http://ipmwww.ncsu.edu/INSECT_ID/AG136/thrips.html


Order Coleoptera (Coleo=sheath, ptera=wing) - Beetles

The well known beetle, the common name of Coleopterans, is the largest order of insects. They account for 40 % of all the known species in the class Insecta. Though this order contains much variety, most beetles are easily identified as such by their similar wings. They tend to have four wings with the front pair thickened, leathery, or hard, and meeting in a straight line down the middle of the dorsal side. These outer wings serve to protect the inner pair and the insects. The hind wings are the only pair used for flight usually. The front protective wings are called elytra and may be rough or shiny and may be brightly colored or dull.

All beetles have chewing mouthparts that can be quite strong. Beetles undergo holometabolous development. Some are predacious and a very few are parasitic but most are scavengers and plant eaters. Due to their diversity, they live in practically all climates inhabited by living things.

Links:
Coleoptera http://phylogeny.arizona.edu/tree/eukaryotes/animals/arthropoda/hexapoda/coleoptera/coleoptera.html
Coleoptera beetle http://www.inscyclo.com/order/coleoptera.htm
Beetles http://www.ent.iastate.edu/imagegal/coleoptera/
Coleoptera: http://www.insect-world.com/main/coleopt.html


Order Strepsiptera (Strepsi=twisted, ptera=wing) - Twistedwinged Parasites

Commonly called twistedwing parasistes, these insects are mostly internal parasites of other insects. Males differ greatly from females in structure. Males have wide heads with compound eyes on the sides. Males also have fan shaped antennae. Their forewings have evolved into clublike structures and the hind wings are membranous and with out venation. Females are without legs, wings, antennae and often eye and remain in the host their entire lives.
The females remain in the host with only their heads protruding. Males leave the host and find females to mate with. The newly hatched, well-developed larvae leave the female and fall from the host to the ground or to plants.

Twistedwing parasites enter their insect hosts as larva through joints or sutures when the host itself is still in its larval stage. From there they undergo what is called "hypermetamorphosis": They molt into another, less mobile, larval form and feed in the host's body cavity. From there they undergo holometabolous metamorphosis. Hosts are not usually killed by infection but may be injured. The shape and color of the abdomen may be changed and the sex organs of the host may be damaged. The male usually causes more damage to the host than the female. Common hosts are various species from the orders Orthoptera, Hemiptera, Hymenoptera and Thysanura.

Links:
Strepsiptera http://www.ag.arizona.edu/ENTO/tree/eukaryotes/animals/arthropoda/hexapoda/strepsiptera/strepsiptera.html
Strepsiptera http://www.gypsymoth.ento.vt.edu/~ravlin/insect_orders/strepsiptera.html
Images of Strepsiptera http://homepages.hrz.tu-darmstadt.de/~pohl/picture.html
The Strepsiptera http://www.insect-world.com/main/stylops.html


Order Mecoptera (Meco=long, ptera=wings) - Scorpionflies

Mecopterans are aptly nicknamed scorpionflies because they look like scorpions with wings. The males have bulblike genital segment that resemble the stinger of a scorpion. A second main distinguishing feature is the elongated face most species have. Most have four long wings. They have chewing mouthparts and undergo holometabolous development. Adults are either predators or scavengers of other insects. Few are plant eaters. Scorpionflies inhabit damp, shady wooded and wetland areas.

Links:
UD Insect Database ? ORDER Mecoptera http://bluehen.ags.udel.edu/homepage/ento/insectdb/mecopter.htm
The Mecoptera http://www.insect-world.com/main/mecop.html
Mecoptera http://www.cals.ncsu.edu/course/ent425/compendium/mecopt~1.html
Mecoptera http://www.gypsymoth.ento.vt.edu/~ravlin/insect_orders/mecoptera.html


Order Lepidoptera (Lepido=scale, ptera=wing) - Butterflies

The most appreciated of all insects, butterflies and moths comprise the order Lepidoptera. The often beautiful wing patterns seen on these creatures are caused by minute, almost powdery scalse that cover the wings and body. Lepidopterans have four large wings that connected together. They have large compound eyes and long antennae. They have sucking mouthparts with which they suck up liquid food. They coil their long, sucking proboscus when not in use. They have fairly good vision and a larger color range than we have (they see ultra-violet). Butterflies and Moths have a holometabolous metamorphosis. The colored scales are loose and slippery, which allows lepidopterans to sometimes escape predators.

There are several ways to distinguish between a butterfly and a moth. Butterflies have hooked or clubbed antennae while most moths have feathery antennae that taper at the end. Butterfly's front and hind wings are connected by a lobed process at the base of the hind wing which grips the underside of the front wing while moths have a stiff bristle called a frenulum at the base of the hind wing that hooks into the underside of the front wing. Most butterflies are diurnal; most moths are nocturnal.

Adults eat flower nectar for the most part and thus are important pollinators. They also eat decaying fruit juices, manure liquids, tree sap, and secretions from insects (honeydew). Some lepidopterans do not feed at all once they become adults.Females deposit eggs on food plants. The eggs give rise to caterpillars with chewing mouthparts. Caterpillars are eating machines with fleshy projections called prolegs. Prolegs have hooks on the underside that make them stick to surfaces. If a larva has more than five prolegs (and no hooks) than it is not a lepidopteran, it's a sawfly larva (Hymenoptera). Caterpillars may be naked or covered in bristlelike hairs (setae). Typically, caterpillars spin cocoons out of silk and undergo metamorphosis to become adults. Some adult butterflies have no mouthparts because their sole purpose is to reproduce, having eaten as caterpillars.

Links:
Electronic Resources on Lepidoptera http://www.chebucto.ns.ca/Environment/NHR/lepidoptera.html
Lepidoptera Collection Furman University http://www.furman.edu/~snyder/butterfly/index.html
The Insects Home Page http://www.insect-world.com/main/six.html
The Butterfly WebSite Http://mgfx.com:80/butterfly/


Order Hymenoptera (Hymeno=membrane, ptera=wings) - Bees, Ants and Wasps

Bees, wasps, ants, sawflies, and allies make up Hymenoptera, one of the most interesting insect orders. Hymenopterans exhibit a great amount of diversity and complexity in their habits. Some members have wings, some don't. Those that do have two pairs which are connected to each other by hooks on the margin of the hind wings. The wings have few veins. Ovipositors are often developed into stingers in this species, therefore only females sting. The mouthpats are often mandibulate but in a few higher forms, bees for example, they are specialized tonguelike structures through which liquid food is taken. In many hymenopteran species the members colonize and have highly specialized roles. Workers are sterile females that feed the young and maintain and defend the nest. Only the queen lays eggs and only a few males, who don't tend to live long, ever mate with the queen. Hymenopterans undergo holometabolousdevelopment.pupa may be formed in a cocoon, in the host (for parasitic forms), or in special cells. The gender of all hymenoptera larvae is determined by fertilization. Unfertilized cells become males and fertilized cells become females.

Links:
The Ant http://www.wesleyan.edu/~jlibsch/Ant/Morphology/index.html
Bees: An inside Look http://hyperion.advanced.org/19579
Bee Online http://www.apitherapy.org/aas/
Wasps http://www.uky.edu/Agriculture/Entomology/entfacts/misc/ef004.htm

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Developed Summer, 1999. Last modified 7/27/99.