Classification: Classifying involves grouping things right into categories based on similar characteristics. Insects, prefer all life organisms, have the right to be classified follow to their phylogenetic relationships. The category system supplied by scientists entails a hierarchy start with a wide category and ending with a very details category. In science, we classify organisms according to kingdom, phylum, class, order, family, genus, and species.

You are watching: Animals that are segmented and have jointed appendages and an exoskeleton are members of the phylum

Nomenclature: Nomenclature refers to the specify name of organisms. Each organism is offered a name consisting of two words referred to as the clinical name. The very first word represents the genus and also the 2nd the species. Clinical names are Latin and are either published in italics or underlined if handwritten. The scientific name for the honey punishment is Apis mellifera.

Identification of Insects and also their Relatives: Insects are part of the phylum of animals called Arthropoda. Every arthropods posses an exoskeleton, bi-lateral symmetry, jointed appendages, segmented bodies, and specialized appendages. The major arthropod classes have the right to be be separated by compare their number of body regions, legs, and antennae.


Major outside Characteristics

1. Exoskeleton containing chitin

2. Human body bilaterally symmetrical

3. Human body segments grouped into devoted regions (= tagmata, plural)

4. Jointed appendages

5. These jointed appendages variously specialized for feeding, locomotion, sensing

Key to the adults of the common Classes the Arthropoda

1a. 2 pairs that antennae (one pair might be reduced, complicated to see);

Number of legs variable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Class Crustacea, walk to 2

1b. One pair the antennae or none. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .go come 3

2a. Two distinctive body areas (cephlothorax and also abdomen);

Five pairs of thoracic legs. . . . . . . . . . . . . . . . . Crayfish, lobsters, shrimp; Order Decapoda

2b. Three unique body areas (head, thorax, abdomen);

Seven bag of thoracic legs . . . . . . . . . . . . . . Sowbugs, pillbugs, roly-polys; Order Isopoda

3a. No antennae; Two distinctive body regions (cephlothorax and also abdomen);

Four bag of legs;. . . . . . . . . . . . . . . . . . Spiders, ticks, scorpions, etc; Class Arachnida

3b. One pair that antennae. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

4a. Three distinct body regions (head, thorax, abdomen);

Three pairs of thoracic legs. Wings existing or absent. . . . . . . . . . . . . . Class Insecta

4b. Two distinct body regions (head and also trunk). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

5a. One pair of legs per trunk segment. . . . . . . . . . . . . . . . . . . . . .centipedes; Class Chilopoda

5b. 2 pairs that legs every trunk segment. . . . . . . . . . . . . . . . Millipedes; Class Diplopoda


Class Crustacea (crus-ta-ce-uh), the crustaceans. This is a really diverse class. Its members display much variation in the tagmata and the appendages. There are about 30,000 varieties of Crustacea. Many are aquatic, the majority of which space marine. Crustaceans has lobsters, crabs, crayfish, shrimp, barnacles, and also several less familiar forms. One of the last is the Isopoda, the sowbugs and pillbugs or roly-polys. Most human being will likely encounter only two orders, the assignment Decapoda and Isopoda.

Order Decapoda (dec-o-po-da). Lobsters, crayfish, crabs, shrimp.

Two tagmata (cephlothorax and abdomen)

Two bag of antennae (can be daunting to watch both pairs) Five bag of legs ~ above the cephlothorax, the an initial pair usually with a huge claw

Order Isopoda (eye-so-po-da). Sowbugs, pillbugs, roly-polys.

Three tagmata (head, thorax and also abdomen)

Two pairs of antennae: first pair is greatly lessened , seldom noticed

Seven bag of legs, one pair on each thoracic segment

Abdomen small, more or less fused.

Most isopods room marine, living in seaweed and also under stones in the water. There room a few freshwater forms. The just Crustacea to attack the land room the isopods However, they have actually not severed every ties v the aquatic habitat because that they are only uncovered in locations of high moisture. This contains places such together leaf litter and also soil and beneath bark and stones. A couple of are periodically pests of grew plants, but they normally feed on necessary debris. Those that deserve to roll into a ball are referred to as pillbugs or roly-polys; those that deserve to not kind a ball space the sowbugs.


Class Arachnida (uh-rak-nid-uh), spiders, ticks, mites, scorpions and also others. This is a diverse course which belongs come a subphylum that the Arthropoda known as the Chelicerata. Chelicerata are characterized as having two distinct body regions, a cephlothorax and also an abdomen. Chelicerates have actually six bag of appendages, the first two pairs being mouthparts and the complying with four pairs being legs. They carry out not have actually antennae.

The an initial pair that mouthparts space the chelicerae (sing., chelicera). They room three-segmented and pincher-like. In spiders, the terminal 3rd segment is often dubbed a fang. The 2nd pair the mouthparts room the six-segmented pedipalps. Lock may appear leg-like (spiders) or claw-like (scorpions). The legs of most Chelicerata have seven segments. Contrasted to insects, whose legs have actually six segments, there is an extra segment, dubbed the patella, between the third segment (the femur) and also the fourth segment (the tibia). Usual orders the Arachnida include:

Order Araneae (a-ran-e-uh), the spiders.Two tagmata (cephlothorax and also abdomen)

No antennae

Abdomen join to cephlothorax by slender pedicel

Four bag of legs

Mouthparts: One pair chelicerae and one pair the pedipalps

Eyes straightforward ocelli. Usually eight, sometimes fewer

Poison apparatus opens on the fangs the the chelicerae

Silk apparatus constantly present at end of abdomen, listed below anus

This is a huge order, having about 2500 types in phibìc America. Although nearly all spiders have venom glands, spiders rarely bite man. Just a couple of U.S. Species are thought about dangerous. In Nebraska, the black widow and also the brown recluse room the only seriously venomous spiders

Order Acari (ak-a-ri), the mites and ticks.

Two tagmata (cephlothorax and also abdomen)

No antennae.

Abdomen broadly joined come cephlothorax (no pedicel).

Four bag of legs in adults; only three bag at hatching

Ticks and mites occur just around anywhere animal life is found. They may be terrestrial or aquatic, free-living or parasitic.They might feed on necessary debris (beneficial scavengers) or on living plants or animals. Few of the tree feeders are major pests of crops. Few of the parasitic forms are pests that animals and also man. Some space vectors that diseases. A few of the predatory and parasitic mites are taken into consideration beneficial since they feeding on insects or various other pests. End 30,000 varieties of ticks and mites have actually been described.

Order Scorpiones (scor-pi-on-es), the scorpions.

Two tagmata (cephlothorax and also abdomen)

No antennae

No pedicel between cephlothorax and abdomen

Four bag of legs ~ above cephlothorax

One pair that chelicerae and one pair that long, pincher-like pedipalpsAbdomen with seven vast segments anteriorly, adhered to by 5 narrower segment which end with a big stinger.

Scorpions feed mainly on insects and spiders i m sorry they capture with their pedipalps. They may or might not sting your prey. Scorpions carry out not ordinarily strike man, however they will certainly sting if disturbed or cornered. Of the forty-some species that happen in the U.S., the sting of most is painful, but not dangerous. One Arizona species, however, is really venomous, and its sting deserve to be fatal.


Class Chilopoda (chi-lo-po-da), the centipedes.


Two tagmata (head and also trunk) One pair the antennae v 14 or much more segments

One pair the legs per trunk segment.

Mouthparts: one pair of mandibles and also two bag of maxillae

Appendages top top the very first trunk segment room clawlike poison jaws or fangs with which centipedes paralysis their prey.

The class name refers to the lip- like appearance the the unify bases of these appendages.

Eyes might be present or absent.

Centipedes are elongate and also flattened. They space usually uncovered in somewhat protected places, such together in sheet litter, in the soil, under bark, or in rotten logs. One types is typically found in houses and other buildings. Centipedes are predatory and also feed top top insects, spiders, and other tiny animals.The bigger centipedes can bite humans, however the bite is no serious and also is no much more painful the the sting of a bee or wasp. The common small centipedes that Nebraska are harmless come man. Overall, centipedes are valuable natural opponents of insects.


Class Diplopoda (dip-low-po-da), the millipedes.


Two tagmata (head and trunk)

One pair of antennae, usually having seven segments

Two pairs of foot on many trunk segments (30 or much more pairs total)

Mouthparts: one pair the mandibles, and one pair of maxillae

Eyes space usually present

Millipedes space usually cylindrical (sometimes contempt flattened). Other than for the very first three trunk segments, every segment has actually two bag of short legs. Millipedes are uncovered in damp places such as the soil, leaf litter, or under logs and also stones. Most millipedes are advantageous scavengers the decaying tree material. A few attack life plants and also are periodically pests. Also fewer room predacious. Millipedes perform not bite man, however many offer off a foul-smelling liquid containing hydrogen cyanide which can be solid enough to kill insects put in a jar v a millipede.


Class Insecta (in- sec-ta), the insects.

See more: What Does Where Art Thou Mean Ing: 5 Examples Of How To Use "Where Arth Thou"

Three tagmata (head, thorax and also abdomen)

One pair of antennae

Three bag of legs

May have actually wings, either one or two pairs

Insects room the most abundant life form now well-known to science. About 1,000,000 varieties have been described and also named. That is more than all the other known animals put together.