5 Orders of Class Insecta
ORDER BLATTODEA (Cockroaches):
- 4,500 species of cockroaches and
- Only about 25 are considered to be pests
- The rest are extremely beneficial insects in a variety of ecosystems
- usually dark brown or reddish in color
- They are omnivorous (they'll eat anything)
- Usually have a flattened oval body
- Long swept-back antennae
- The proton ( a shield like structure on the top of the thorax behind the head) often overhangs the body on either side and covers the head.
- Not all species have wings, but the forewings are thick and leathery whereas the hind wings are thin and fan-like, overlapping one another
ORDER HYMENOPTERA (wasps, bees and ants):
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ORDER LEPIDOPTERA (butterflies and moths):
- 175,000 species
- The scientific name of the order, Lepidoptera, is derived from one of their main characteristics, namely their having wings covered in tiny scales (from the Greek lepidos = scale and pteron = wing)
- They undergo complete metamorphosis, i.e. ova (egg), from which emerge larvae (caterpillars), which become the quiescent pupae (chrysalis) from which emerge the imago (winged adult).
- Lepidoptera are 'typical' insects, in that they have 4 wings, 6 legs, 2 antennae and a body divided into 3 sections - a head, thorax and abdomen. The leg and wings are attached to the thorax.
- They have modified, flattened hairs on their wings known as scales. The scales give them a wide range of colours and patterns
- Butterflys are mostly day flyers, whereas moths are night flyers
- Most butterflies and moths feed through a specialised tube formed by some of the mouthparts, known as a proboscis. Nectar is the usual food for adults.
- Sense organs on the feet can taste certain food substances with a greater sensitivity than the human tongue.
- Butterflies have slimmer bodies with thin antennae and distinct clubs at the end
ORDER DIPTERA (flies):
- 240,000 species
- It contains pests like house flies and fruit flies, smaller biting insects like gnats and midges, and the deadliest animal on the planet, the mosquito.
- The muscles that operate the forewings are well developed and situated in the mid-section of the insect's thorax
- flies hind wings have become modified into balance organs, or halteres, which provide a high level of control during flight
- The mouthparts of flies are designed to suck or pierce, rather than bite, and they are all liquid feeders
- Flies can play a useful role in feeding on decaying matter and in pollinating
- Many families of flies are blood sucking, and while they are feeding can transmit serious disease - including yellow fever, malaria and sleeping sickness. Some are also agricultural pests
- Complete metamorphosis
COLEOPTERA (beetles):
- Largest group of insects world wide with 370,000 species
- Some of the most popular insects are classified in the order, including ladybugs, fireflies, rhino beetles, and goliath beetles (the heaviest of all insects)
- Complete metamorphosis
- A high proportion of beetle species are able to fly and these possess two pairs of wings
- In most species the forewings consist of a pair of hard shells that protect the membranous hindwings which are normally folded away, but hinge outwards during flight
- Beetles can be found in almost every imaginable terrestrial or aquatic habitat but many more species are found in tropical countries than in places with more temperate climates
- A number of beetle species are dependant upon other insects for their survival