HYMENOPTERA: SAWFLIES,WASPS,ANTS & BEES
DIPTERA: TRUE FLIES,MECOPTERA,SCORPIONFLIES,BOREIDAE,SIPHONAPTERA,TRICHOPTERA,CADDISFLIES
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Hymenoptera of the world
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HYMENOPTERA
Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones.
Females typically have a special ovipositor for inserting eggs into hosts or places that are otherwise inaccessible. The ovipositor is often modified into a stinger. The young develop through holometabolism - that is, they have a worm-like larval stage and an inactive pupal stage before they mature.
Hymenopterans range in size from very small to large insects, and usually have two pairs of wings. Their mouthparts are adapted for chewing, with well-developed mandibles (ectognathous mouthparts). Many species have further developed the mouthparts into a lengthy proboscis, with which they can drink liquids, such as nectar. They have large compound eyes, and typically three simple eyes, ocelli.
Different species of Hymenoptera show a wide range of feeding habits. The most primitive forms are typically herbivorous, feeding on leaves or pine needles. Stinging wasps are predators, and will provision their larvae with immobilised prey, while bees feed on nectar and pollen.
A huge number of species are parasitoids as larvae. The adults inject the eggs into a host, which they begin to consume after hatching. For example, the eggs of the endangered Papilio homerus are parasitized at a rate of 77%, mainly by Hymenoptera species. Some species are even hyperparasitoid, with the host itself being another parasitoid insect. Habits intermediate between those of the herbivorous and parasitoid forms are shown in some hymenopterans, which inhabit the galls or nests of other insects, stealing their food, and eventually killing and eating the occupant.
DIPTERA Flies are insects with a pair of functional wings for flight and a pair of vestigial hindwings called halteres for balance. They are classified as an order called Diptera. The order Diptera is divided into two suborders ,with about 110 families divided between them; the families contain an estimated 1,000,000 species, including the familiar housefly, horse-fly, crane fly, and hoverfly; although only about 125,000 species have a species description published. The earliest fly fossils found so far are from the Triassic, about 240 million years ago; phylogenetic analysis suggests that flies originated in the Permian, about 260 million years ago.
Flies have a mobile head, with a pair of large compound eyes, and mouthparts designed for piercing and sucking (mosquitoes, black flies and robber flies), or for lapping and sucking in the other groups. The suborder Nematocera have thin, long antennae; while the suborder Brachycera have short antennae. Flies have only a single pair of wings to fly; their arrangement gives them great maneuverability in flight. The hindwings evolved into advanced mechanosensory organs, which act as high-speed sensors of rotational movement and allow them to perform advanced aerobatics. Claws and pads on their feet enable them to cling to smooth surfaces.
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