Insect Taxonomic DiversityBY: CLIFTON BALL

ZOOLOGY 7TH

Insect Orders

Ephemeroptera

Odonata

Blattaria

Isoptera

Dermatptera

Orthoptera

Phasmida

Hemipter

Cleoptera

Lepidoptera

Diptera

Siphonoptera

Hymenoptera

Mantodea

Plecoptera

Ephemeroptera

Adult: body delicate or "flimsy", varying from almost transparent to white, yellow, orange, green, brown, or black; thorax and abdomen bare, often shiny; legs slender, solid color; front legs often held forward and sometimes upward in front of head when at rest; forewings large, triangular, with many cross veins; hind wings much smaller than forewings (hind wings absent in some species); both wings usually transparent but sometimes patterned, held vertically and together above thorax when at rest

Pre-adult: wings cloudy in appearance, body dull and pubescent, with appendages somewhat shorter -- but otherwise similar to imago; pre-adults molt a final time to become adults

Nymph: body elongate, flattened or cylindrical, usually greenish or brownish but color varies according to the type of food eaten; legs long; antennae short; abdomen with lateral plate-like gills and usually three long thin tail projections (cerci); some species have only two cerci

Odonata

CharacteristicsThese often brightly colored, fast flying insects are well known and easily recognized. Dragonflies and damselflies are medium to large insects with body lengths ranging from 15-120 millimetres. They are often seen flying rapidly over streams and lakes, or through gardens at dusk, often following regular flight paths every day. Dragonflies and damselflies can be recognized by the following features: Abdomen long and slender

Large compound eyes

3 ocelli

Very small antennae

Mandibulate mouthparts

Two pairs of membranous wings of similar shape and size

Complex wing venation with many cells

Damselflies and dragonflies are very similar but can be separated by looking at their wings. In dragonflies the hind wings are slightly broader than the forewings and in damselflies both wings are more or less similar size. Wings are held horizontally to the body in dragonflies and vertically in damselflies when at rest.

Blattaria

Cockroaches are long, flat, brown insects. Their heads point downward and have chewing mouthparts. A plate from the top of the thorax covers the head when you look down on them, so you can't actually see the head. They are very fast runners. They have long antennae, and at the end of the abdomen are two short antennae-like structures that sense air current and vibrations.

Other Physical Features : bilateral symmetry

Sexual Dimorphism : female larger

Isoptera

CharacteristicsTermites are small to medium sized insects ranging form 3-20 millimetres in body length. These insects are not often seen although evidence of their presence is observable in the large mounds they construct or the damage they do to wood products and structures. Termites can be distinguished by the following features: Pale, elongate body

2 pairs of membranous wings of equal length. Wings are present in reproductive castes only and shed after mating

Mandibulate (chewing) mouthparts

Antennae about the same length as the head

Dermatptera

CharacteristicsEarwigs are a distinctive group of insects of small to medium size, ranging from 5 to 50 millimetres in length. Earwigs are sometimes confused with Staphylinid beetles, but can be distinguished from the latter by the presence of pincer-like cerci, which Staphylinid beetles lack. Earwigs are mostly dark colored (brown to black) and can be recognized by the following features: Flattened elongated body

Heavily sclerotized pincer-like cerci. Females have straight cerci with a inward pointing tip and males have curved cerci

2 pairs of wings. The forewings are short and protectively hardened. The hind wings are membranous and folded in a fan-like way underneath the forewings when not in use. Some species are also wingless

Chewing (mandibulate) mouthparts

Moderately long antennae

Orthoptera

CharacteristicsGrasshoppers, crickets, katydids and locusts all belong to the order Orthoptera which means 'straight wings'. Most are easily recognisable by their hind legs, which are usually enlarged for jumping. They are often easily seen jumping away when disturbed or heard 'singing' at night. They are mainly medium to large insects with some species in Australia growing to a length of 10 centimeters. There are about 3000 species in Australia and all can be distinguished from other insects by the following features: 2 pairs of wings. The forewings are narrower than the hind wings and hardened or leathery at the base. They are held roof-like overlapping the abdomen at rest. The hind wing is membranous and held folded fan-like under the forewings when at rest

Mandibulate mouthparts

Large compound eyes

Antennae may be short to very long depending on the species. Grasshoppers have relatively short antennae while crickets and katydids generally have long antennae

Hind legs are enlarged and modified for jumping

Phasmida

Identification

Body and legs very long and slender; no wings in our spp. (one species in Florida has very short wings, many exotic forms are fully winged)

Hemiptera

Hemiptera: bugs, aphids and cicadas

CharacteristicsThe insects in this order are extremely diverse in their size, shape and color. There are about 6000 described species in Australia, ranging in size from 1 to 110 millimetres in length. The name Hemiptera means 'half wing' and all hemipterans share the following features:2 pairs of wings, although some species may be wingless and others have only forewings. Wings are generally membranous but in some species the forewings may be hardened at the base

Piercing or sucking mouthparts appearing as a sharply pointed tube known as a proboscis or rostrum, which extends from the underside of the head

Compound eyes of various forms

Up to 3 ocelli present

Antennae vary and may be either short, or long and conspicuous

The young of hemipterans look like small adults. Some bugs may be mistaken for beetles but can be distinguished by their mouthparts as beetles have mandibulate mouthparts while bugs have sucking/piercing mouthparts.

This order is divided into 3 suborders; true bugs (Heteroptera); hoppers (Auchenorrhyncha) and; aphids, scale insects, lerps and mealy bugs (Sternorrhyncha).

Coleoptera

CharacteristicsBeetles constitute the largest and most diverse order of insects on earth, making up about 30% of all animals. There are over 300 000 species of beetles worldwide and over 28 000 species spread across 117 families in Australia. Beetles come in a variety of shapes and colors and can range from 0.4 to about 80 millimetres in length. Due to the variation within the order it is difficult to give a general description however all beetles characteristically have the following features:2 pairs of wings. Forewings hardened, hind wings membranous

Mandibulate mouthparts which are designed for biting and chewing

Antennae present in a variety of forms

Compound eyes in a variety of sizes and shape

Lepidoptera

CharacteristicsThis is one of the most well known and easily recognisable orders of insects and contains about 21 000 species in Australia. Moths and butterflies are grouped together in the order Lepidoptera, which means 'scaly wings'. Below are the main characteristics of butterflies and moths. 2 pairs of membranous wings that are covered in tiny scales which overlap like shingles on a roof. A few moths are wingless

Large compound eyes

One ocelli present above each eye

Antennae present. Antennae are long and slender in female moths and generally feathery in male moths. Butterflies have clubbed antennae

Mouthparts are formed into a sucking tube known as a haustellum

The larvae are typically known as caterpillars and have a sclerotized head with chewing (manipulate) mouthparts, 3 pairs of thoracic legs and often short, unsegment prolegs on the abdomen.

Diptera

Immatures:

Culiciform Head capsule present with chewing mouthparts

Legs absent

Vermiform (maggots) Without legs or a distinct head capsule

Mouthparts reduced; only present as mouth hooks

Adults:

Antennae filiform, sty late, or aristate

Mouthparts sectorial (haustellate)

Mesothorax larger than pro- or metathorax

One pair of wings (front); hind wings reduced (halters)

Tarsi 5-segmented

Siphonoptera

CharacteristicsFleas are small, wingless insects ranging in size from approximately 1-10 millimetres in length depending on the species. Almost everybody, especially those with cats or dogs will be familiar with these small biting insects and will have either seen them or the effects of their nuisance bites. Fleas can be recognized by the following features: Laterally compressed bodies

Piercing-sucking mouthparts

Enlarged hind legs adapted for jumping

Strong tarsal claws adapted for holding onto their hosts

Backward pointing hairs and bristles for ease of movement through the hair of a host

Small antennae which tuck away into special groves in the head

Hymenoptera

Typically two pairs of wings, with forewings usually larger than hind wings, but some groups (such as ants) wingless in most life stages.

Wings have few cross-veins, these are angled to form closed cells.

Antennae typically with 10 or more segments. Often 13 segments in male, 12 in female, but sometimes as few as 3 or up to 60 segments.

Antennae longer than head, but usually not highly elongated (longer than head and thorax combined). Highly elongated in some parasitic groups.

Females have prominent ovipositor, modified in some groups to be a "stinger", used to paralyze prey and for defense.

Chewing mouthparts, but some groups have a "tongue" used for lapping up fluids, such as nectar.

Complete metamorphosis.

Several groups highly social (eusocial), with separate reproductive and worker castes.

Mantodea

CharacteristicsPraying mantis are often easily recognized due to their large size, which can range from 10 to 120 millimetres in body length and their characteristic way of standing with forelegs held together as if they were praying. All praying mantis have the following features: Elongated body

Raptorial front legs with one or two rows of spines

2 pairs of wings, both of which are used in flight. Although some species have reduced wings and others are wingless

Forewings protectively hardened to cover the membranous hind wings when at rest

Very mobile triangular shaped head with distinctive ocelli

Large compound eyes

Short to medium sized filiform antennae

The males of most species are fully winged while many females have either reduced wings or no wings at all. The nymphs of praying mantis look like small adults but lack wings or have developing wing buds.

Some species of Neuroptera in the family Mantispidae, like the one pictured below can be mistaken for praying mantis as they also have raptorial front legs, however further examination reveals they do not have the hardened forewings present in Mantodea.

Plecoptera

CharacteristicsStoneflies are soft-bodied insects that can grow up to 50 millimetres long with a wingspan of 100 millimetres. Adult stoneflies are always found near freshwater as they have aquatic larvae and as adults they are not powerful fliers. They therefore have poor dispersal capabilities are rarely move far from the place they were born. Stoneflies are recognisable by the following characteristics:Elongated, flattened, soft body

2 pairs of membranous wings that are held curved around the body at rest. Some species are wingless while others have reduced wings

Hind wings slightly wider than forewings

Long legs

Mandibulate mouthparts

2 cerci at tip of abdomen

The larvae of stoneflies are aquatic and appear similar to the adults but lack wings. Larvae also possess external gills along the edge of their abdomens and at the tip.

The End