Agriculture Reference
In-Depth Information
Wind
—Wind speed and direction can greatly alter the effectiveness of a
pesticide application. Excessive wind can blow the pesticide off target and
result in inadequate control. Even moderate winds can greatly alter the cover-
age of ULV and mist blower applications. Sometimes the applicator can
compensate for minor winds by applying the pesticides at an angle where the
winds blow the chemical towards the area to be protected.
II.
INSECTS
There are more kinds of insects on earth than all other living animals
combined. They are found in soil, hot springs, water, snow, air, and inside
plants and animals. They eat the choicest foods from our table. They can
even eat the table.
The large number of insects can be divided into three categories according
to their importance to man:
•
species of minor importance—About 99 percent of all species are in
this category. They are food for birds, fish, mammals, reptiles, am-
phibians and other insects. Some have aesthetic value.
•
beneficial insects—In this small but important group are the preda-
tors and parasites that feed on destructive insects, mites, and weeds.
Examples are ladybird beetles, some bugs, ground beetles, tachinid
flies, praying mantids, many tiny parasitic wasps, and predaceous
mites. Also in this category are the pollinating insects, such as
bumbl ebees and honey bees, some moths , butterflies, and beetl es.
Without pollinators, many kinds of plants could not grow. Honey
from honeybees is food for humans. Secretions from some insects
are made into dyes and paints. Silk comes from the cocoons of silk
worms.
•
destructive insects—Although this is the category which usually
comes to mind when insects are mentioned, it includes the fewest
number of species. These are the insects that feed on, cause injury
to, or transmit disease to humans, animals, plants, food, fiber, and
structures. In this category are, for example, aphids, beetles, fleas,
mosquitoes, caterpillars, and termites.
A.
PHYSICAL CHARACTERISTICS
All insects in the adult stage have two physical characteristics in com-
mon. They have three pairs of jointed legs, and they have three body regions
