In the insect world a constant struggle for survival is going on. On the one hand, the insects themselves are provided with potentialities for tremendous increase. The females lay hundreds of eggs, and some species produce many generations a year. If all individuals survived, the world would soon be overrun with the progeny. On the other hand, insects must contend with many adverse conditions, which serve to hold their numbers in check. Weather conditions, abudance or lack of food, prevalence of natural enemies, and many other factors have an influence in determining their abudance. Some of the more important of these factors are considered in the following paragraphs.
Climatic factors such as temperature, moisture, and unusual weather conditions have an important bearing on the activity, periodic abundance, and distribution of insects.…
