PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
ABDOMEN
The abdomen is made up of a number of segments joined by flexible membranes. Up to
11 segments may be present though the number is often less. In addition, several segments may be
much reduced or modified for mating so that in some cases there may only be 4-5 segments.
PROLEGS
LARVAE OF SOME INSECTS HAVE PROLEGS
Moth, butterfly and some sawfly larvae have prolegs.
Prolegs develop on the abdomen and are not true jointed legs.
They assist with walking and attachment to their host plant.
Grape vine moth caterpillar
NUMBER OF PROLEGS VARY
Larvae of butterflies and moths have up to 5 pairs.
Larvae of some sawflies have 6-8 pairs.
SEXUAL
APPENDAGES
CERCI
Some insects have a pair of cerci located at the tip of the abdomen. They are
used for feeling and are often used during mating.
Earwigs
OVIPOSITORS
Some females, eg wasp parasites, have long ovipositors (tubes) for
depositing their eggs deeply in tissue. They usually arise from beneath
segments 8 and 9.
In bees, wasps and some ants, the ovipositor is also a stinging organ.
Parasitic wasp
CLASPING OR HOLDING ORGANS
These occur in male insects, are used during mating and are usually on
the 9 th segment.
If the 5 th pair of prolegs on moth larvae are well developed they may also
be called claspers. Caterpillars of the doubleheaded hawk moth are huge
(up to 12 cm long). The terminal claspers are very large and at first glance
could be mistaken for the head, hence the insect's common name.
16 Insects and allied pests - Biology