Classification Of Bugs

This is a guide to the classes and orders of insects and other arthropods.

The Insecta (insects) are a Class of the large anymal Phylum called ARTHROPODA (arthropods) - a name that refers to the jointed limbs. The other major classes of living arthropods (i.e. animals related to insects) include Crustacea (crabs, lobsters, shrimps, barnacles, woodice, etc.), the Myriapoda (millipedes, centipedes, etc) and the Arachnida (scorpions, king crabs, spiders, mites, ticks, etc). In addition there are several minor classes, the Onychophora (velvet worms), Tardigrada (water bears), Pentastomida (tongue worms) and Pygnogonida (sea spiders), all of witch contain somewhat aberrant living forms of uncertain affinities to the any of the preciding groups, and finally the Class of extinct arthropods, the Trilobita (trilobites), known only from their fossil remains. All these animal are characterised by the though outer body-shell or exoskeleton, with flexible joints between the skeletal plates to allow the animal to move.

Class	Main Body Region	Pairs Of Legs	Pairs Of Antenna	Wings
Crustacea	two - cephalothorax* and abdomen (some with head and trunk	five or more	two	absent
Myriaopoda	two - head and trunk	many - one or two per trunk segment	one	absent
Arachnid	two - cephalothorax* and abdomen	four	none (though palps may resemble antennae or legs)	absent
Insecta	three - head, thorax and abdomen	three	one	usually present (but many wingless form)

*cephalothorax = fused head and thorax

Each of the Classes of arthropods, including the insects are split into a number of smaller groups, which reflect progressively more detailed structural similarities between the group member. These smaller groups follow a strict hierarchy. The major class division in descending order of size are called Subclass, Order, Suborder, Family, Subfamily and Genus. A Genus is the smallest group of any real importance in the naming of individual species, although in some classifications generic groups may be further spllit into Subgenera. The scientific name of a species includes, first, the Genus to which it belongs and, second, its specific name, e.g. the European Violet Ground Beetle is called Carabus violaceus, meaning the species violaceus in the Genus Carabus (by convention, generic and specific names are always printed in italics; the generic name spelt with a capital letter and the specific name with a smaller letter). The full classification of insect would be as follow :

PHYLUM :	Arthropoda	arthropod
CLASS :	Insecta	insect
SUBCLASS :	Pterygota	winged insect
ORDER :	Coleoptera	beetle
SUBORDER :	Adephaga	carnivorous beetle
FAMILY :	Carabidae	ground beetle
SUBFAMILY :	Carabinae	-
GENUS :	Carabus	-
SPECIES :	Carabus violaceus L.	violet ground beetle

The name of author who first describes a species, or recognised of the aurhor's name, is sometimes quoted after the specific name of the animal, in this case L. = Linnaeus (the Swedish naturalist who firmly established the binomial system for naming animal and plant in 1753, and who published the first descriptive account of this particular beetle).

Class Crustacea

Excluding one or two very small groups of shrimps, the crustaceans are split into 9 main Orders, as listed below. They nearly all live in water and range from minute planktonic shrimp-like creatures, such as water flea, to the large, more familiar, crabs and lobsters. Some members of the Isopoda are the only forms that have really invaded the land and most of these are largerly confined to damp places.

ORDER	COMMON NAME
1. Branchiopoda	Water Fleas (Daphnia), Fairy, Brine, Tadpole, and Clam Shrimps
2. Copepoda	Water Fleas (Cyclops), Fish Lice, Gill Maggots and Anchor Worms
3. Ostracoda	Seed Shrimps
4. Cirrepedia	Barnacles
5. Stomatopoda	Mantis Shrimps
6. Mysidacea	Opossum Shrimps
7. Decapoda	Shrimps, Prawns, Lobsters, Crayfish and Crabs
8. Amphipoda	Freshwater Shrimps (Gammarus) and Sand Hoppers
9. Isopoda	Sea Slatters, Water Slatters, Water Lice and Hog Lice
Isopoda: Oniscoidea (part)	Woodlice

Class Myriapoda

There are four groups of centipede-like creatures known collectively as myriapods. These are listed here as Orders of the Class Myriapoda, but in many arthropod classification they are given status of separated Classes.

ORDER	COMMON NAME
1. Pauropoda	-
2. Symphylia	-
3. Diplopoda	Millipedes
4. Chilopoda	-

Class Arachnid

The arachnids are usually split into 8 main Orders, as listed below.

ORDER	COMMON NAME
1. Xiphosura	King Crabs or Horseshoe Crabs
2. Pseudoscorpiones (=Chernetidae)	Pseudoscorpions or False Scorpions
3. Scorpionidae	Scorpions
4. Pedipalpi	Whip Scorpions
5. Solifuga (=Solpugae)	Wind Scorpions or Barrel Spiders
6. Opiliones (=Phalangidae)	Harvestmen or Harvest Spiders
7. Acari (=Acarina)	Mites and Ticks
8. Araneae	True Spiders

Class Insecta

The insects are generally sub-divided into 29 Orders. These are listed below describing general characteristics, recognition features and examples of eact Orders.

ORDER	COMMON NAME	SUBCLASSES & FEATURES
1. Thysanura	Bristletails	APTERYGOTA These are wingless insects and their body structure suggests that they never had wings during their evolutionary history. Young stages resemble the adults – little or no metamorphosis
2. Diplura	Two-pronged Bristletails
3. Protura	-
4. Collembola	Springtails
5. Ephemeroptera	Mayflies	PTERYGOTA Division EXOPTERYGOTA These are winged insects, although some have lost their wings during the course of evolution. When present, the wing develop externally and there is no marked change (metamorphosis) during the life cycle. The young stages, called nymph, resemble the adult except in seze and in lacking fully-developed wings – simply metamorphosis.
6. Odonata	Dragonflies
7. Plecoptera	Stoneflies
8. Grylloblattodea	-
9. Orthroptera	Crickets, Grasshoppers and Locusts
10. Phasmida	Stick and Leaf Insects
11. Dermaptera	Earwings
12. Embioptera	Web-spinners
13. Dictyoptera	Cockroaches and Mantids
14. Isoptera	Termites
15. Zoraptera	-
16. Psocoptera	Psocids and Booklice
17. Mallophaga	Biting Lice
18. Siphunculata (=Anoplura)	Sucking Lice
19. Hemiptera	True Bugs
20. Thysanoptera	Thrips
21. Neuroptera	Alder Flies, Snake Flies and Lacewings	PTERYGOTA Division ENDOPTERYGOTA These are winged insects, although some have lost their wings during the course of evolution. When present, the wings develop internally (i.e. inside the body of the immature insect) and there is a marked change (metamorphosis) during the life cycle. The young stages are very different from the adults and are called larvae. The change from larva to adult takes place during a non-feeding stage called the pupa (or chrysalis) – complex metamorphosis.
22. Coleoptera	Beetles
23. Strepsiptera	Stylopids
24. Mecoptera	Scorpion Flies
25. Shiponaptera	Flea
26. Diptera	True Flies
27. Lepidoptera	Butterflies and Moths
28. Tricoptera	Caddis Flies
29. Hymenoptera	Bees, Wasps and Ants

Thanks to Dr David Kendall BSc PhD