Agriculture Reference
In-Depth Information
C.
INSECT-LIKE PESTS
Mites, ticks, spiders, sowbugs, pillbugs, centipedes, and millipedes re-
semble insects in size, shape, life cycle, and habits. Pest species usually can
be controlled with the same techniques and materials used to control insects.
Figure 3.2A
Incomplete metamorphosis. Grasshopper passes through three
stages of development: egg, naiad, and adult.
Figure 3.2B
Complete metamorphosis. Fly passes through four stages of
development: egg, larva, pupa, and adult.
1.
Arachnids
Ticks, scorpions, spiders, and mites have eight legs and only two body
regions. They are wingless and lack antennae. The metamorphosis is gradual
and includes both larval and nymphal stages. Eggs hatch into larvae (six legs)
which become nymphs (eight legs) and then adults. Ticks and mites have
modified piercing-sucking mouthparts; spiders and scorpions have chewing
mouthparts.
Figure 3.3
is an illustration of a brown recluse spider.
2.
Crustaceans
Sowbu gs, also known as pillb ugs, water fleas , and wood lice have 14
legs. They are wingl ess and contain only one segmented body regio n. They
have two pairs of antennae and chewing mouthparts. Sowbugs and pillbugs
have a hard, protective shell-like covering and are related to the aquatic lob-
sters, crabs, and crayfish. The metamorphosis is gradual, and there may be up
to 20 instars before adulthood is reached.
Figures 3.4
and
3.5
picture the pill-
bug sometimes called the sowbug.
