Ganeshaiah, K. N. “Why Are Insects Abundant? Chance or Design?.” In Indian Insects , pp. 1-6. CRC Press, 2019.
Beetles have become a subject of special attention to biologists, not just because of Haldane’s quip, but due to two of their features: they are the most species rich group, and hence by derivation, they are considered the most diverse group of organisms. Based purely on the numbers of species in different orders of insects, beetles do seem to be uniquely species rich. For instance, beetles may have become predominant in the early stages due to their shifting to feeding on angiosperms, or due to their wing flexion, or complete metamorphosis. When the numbers of species in different orders are plotted against their size rank an interesting and a very revealing pattern emerges. The observed exponential increase suggests that the number of species added increases with the order size; that means the higher the size rank of an order, there are disproportionately higher numbers of species in it.