Agriculture Reference
In-Depth Information
3.
Abdomen
The abdomen is usually composed of 11 segments. Along each side of
most of the segments are openings (called spiracles) through which the insect
breathes. In some insects, the tip end of the abdomen carries tail-like append-
ages.
B.
INSECT DEVELOPMENT
Most insect reproduction results from the males fertilizing the females.
The females of some aphids and parasitic wasps produce eggs without mating.
In some of these insect species, males are unknown. A few insects give birth
to living young; however, life for most insects begins as an egg. Tempera-
ture, humidity, and light are some of the major factors influencing the time of
hatching. Eggs come in various sizes and shapes—elongate, round, oval, and
flat. Eggs of cockroaches, grasshoppers, and praying mantids are laid in cap-
sules. Eggs may be deposited singly or in masses on or near the host—in
soil or on plants, animals, or structures.
Figure 3.1
The adult ant (EPA,
Urban Integrated Pest Management: A
Guide for Commercial Applicators
).
1.
Metamorphosis
The series of changes through which an insect passes in its growth from
egg to adult is called metamorphosis.
When the young first hatche from an egg, it is either a larva, nymph, or
naiad. After feeding for a time, the young grows to a point where the skin
cannot stretch further; the young molts, and new skin is formed. The number
of these stages (called instars) varies with different insect species and, in some
