the use of sterile techniques to control or to eradicate insect population
has been one of the revolutionary departures in the modern Entomology. For
monogamous species, in which a male participates in numerous matings
whereas a female accepts only one mate, the sterile-male technique is
especially plausible. To achieve sterility, two methods have been
extensively investigated, namely the use of X-rays or gamma rays from
Cobolt 60 and chemosterilants. Sterilization by irradiation often reduces
mating competitiveness that may be avoided by chemosterilants with
selective action. Furthermore, there is a possibility that some
chemosterilants may be used in the natural environment to control pests,
thus avoiding the necessity of rearing, sexing, treating and releasing of
insects. for this reason, chemosterilants have received considerable
attention in the recent years. Thousands of chemicals have been tested for
the sterilization in insects is till far from clear. Lethal mutation was
usually assumed to be the reason of chemosterilization but without
adequate evidences. In many cases, chromosome abnormalities, reduction in
numbwe of germ cells, degeneration of gonads and
sperm inactivation, or no cleavage of embryos in the chemosterilized
insects have also been reported. An immediate question is that how many of
these effects are responsible for the sterilization? Different sterilizing
effects may be resulted from different category of chemosterilants on
different individuals of different developmental stages of same species.
Therefore, and emphasis so placed, it is necessary to investigate ghe
general mechanism by pursuing the primary effects caused by
chemosterilants. Provided such aim can be achieved through the suitable
treatment by a chemical on a species of insect which is familiar to all.
It was then, decided to study the male sterilization by tepa on house fly.

or accessory glands,