Page:Popular Science Monthly Volume 81.djvu/480

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
474
THE POPULAR SCIENCE MONTHLY

mous that the latter cause but little apparent depletion in their ranks. Many of our song birds eat them, as well as black-birds and crows. The sparrow-hawk's crop is filled with them in the fall, and at least one variety of tern helps the farmer materially in this direction. Skunks and other predatory mammals are partial to them, and we have per- sonally observed the thirteen-lined gopher (Sphermophilus tridecem- lineatus) catching and devouring them in the cool mornings of autumn. Among insect enemies, parasitic and predaceous flies are very useful in their attack upon the eggs as well as upon the hoppers themselves. Various beetles, notably some of the meloids or "Blister Beetles," insects which are themselves destructive to crops in the adult stage, make some amends for their destructiveness by preying upon the eggs.

Farmers, seeing small mites fastened to the wings and bodies of grasshoppers, have been wont to comfort themselves with the thought that these animals were reducing the number of the pests. Inasmuch as we have seen female hoppers in the fall, laden with these possible parasites, laying eggs for the next generation, having themselves com- pleted their destructive life history, we believe too much reliance has been placed upon this phenomenon in the past and are inclined to regard their occurrence on grasshoppers as a means of dispersal of the species of mite in question, rather than a serious drain upon the vitality of the grasshopper.

It would seem, then, that the farmer must rely principally upon his own effort in this warfare, unless forsooth nature favors him by sending many cold drenching rains in May and June when the hoppers are hatching, which not only result in great mortality amongst the insects themselves, but give the crops such a stimulus that they are better enabled to withstand the inroad of these pests.