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Order
- HEMIPTERA
(Greek, hemi = half; pteron = wing)
Common Names: bugs, leafhoppers, cicadas,
aphids, scale insects.
Distribution:
Cosmopolitan
Suborders: Sternorrhyncha, Auchenorrhyncha,
Heteroptera
Description
Bugs possess piercing-sucking mouthparts in a "simple" tube
(rostrum) formed by modification of the insect’s lower lip (labium).
Inside the tube, modified mandibles form canals which allow an upward flow
of liquid food and a downward flow of saliva. The modified mandibles are
called stylets. Often the rostrum is held under the head but is brought
forward during feeding. Compound eyes are usually present and well
developed; simple eyes (ocelli) may be present. Antennae may be short with
only a few segments, or well developed and more or less filiform. Most
species possess two pairs of wings, but some have only one pair and a few
species have none. The Order name describes a character of the many bugs
in which the front pair of wings is modified so that the basal half of
each wing is hardened (sclerotised) to form a protective cover (a
hemelytra). As the wings of bugs are folded flat on the abdomen, this
makes the insect appear as if half of each of the forewings is missing. In
the remainder of the order, the wings are held over the abdomen rather
like the two sides of a house roof (cicadas, etc.). True bugs (suborder
Heteroptera) often produce a repellent odour - used for defence - from a
specialised gland.
Nymph
Bugs emerge from eggs as wingless miniatures of the adults (nymphs) and
mature by successive moults. Some members are viviparous (give birth to
live young - aphids), while others have extended nymphal lives of up to 17
years (some species of cicada).
Members
Bugs, water striders, water scorpions, water bugs, water boatmen, cicadas,
leaf hoppers, spittlebugs, aphids, psyllids or lerp-insects, scale insects
and whiteflies.
Food
Bugs feed on liquid obtained from plants or animals including man. Any
part of the plant may be used as food: leaves, stems, fruits or roots.
Blood is consumed by some species, while others consume insect body fluid.
Importance
The plant feeding bugs are considered serious pests in horticulture. Large
amounts of damage can be done to stone fruit, citrus and vegetable crops
by such insects as the green vegetable bug, the Rutherglen bug and the
harlequin bug. Scale infestations can seriously damage citrus crops and
ornamentals, and aphid attacks can harm various ornamentals such as roses.
The underground aphid Phylloxera vitifoliae very nearly destroyed
the French wine industry and seriously affected the Australian industry
until resistant root-stocks were discovered. In Australia, lerp-insects
can defoliate large tracts of eucalypt forest. |