. Injurious and useful insects; an introduction to the study of economic entomology. Insects; Beneficial insects; Insect pests. Fig. 8i.—Bot-fly of horse, male. After Bracy Clark. he know how much trouble will arise from these apparently insignificant attentions! A female fly, bent upon laying her eggs, hovers about the horse with her body almost vertical, and now and then, hardly settling, touches his skin with the tip of her abdomen. At that instant a sticky egg is passed out and glued to one of the hairs, usually near its tip. In a very short time the sticky substance sets hard, and the egg
. Injurious and useful insects; an introduction to the study of economic entomology. Insects; Beneficial insects; Insect pests. Fig. 8i.—Bot-fly of horse, male. After Bracy Clark. he know how much trouble will arise from these apparently insignificant attentions! A female fly, bent upon laying her eggs, hovers about the horse with her body almost vertical, and now and then, hardly settling, touches his skin with the tip of her abdomen. At that instant a sticky egg is passed out and glued to one of the hairs, usually near its tip. In a very short time the sticky substance sets hard, and the egg is then so firmly cemented that no ordinary means can remove it. The eggs are not laid at random, but most commonly upon the inside of the knee, on the flanks, or on the hinder part of the shoulder, never on any part of the horse which is out of reach of his tongue. When the first egg has been made fast, the fly retreats for a moment, brings a second egg into the tube, and returns to attach it in the same way. One female fly may contain 600-700 eggs, and nearly that number will sometimes be found on a single horse. The eggs are white when quite fresh, afterwards turning yellow, and since they are large enough to be seen by the naked eye, they are some- times very conspicuous on a dark- coloured animal. The fly delights in warm, sunny weather, and shelters during cold or rain, so that we can guess when eggs are likely to be laid; it does not .enter stables. The eggs of the bot-fly are destined, if fortune favours them, to produce larvK, which will enter the stomach of the horse, and there feed at his expense till they are ready to pupate. We might guess that the horse would be induced in some way or other to swallow the egg, and so at once make himself the dupe of the fly. But this is not precisely the method of nature. The egg is cemented so fast that the horse cannot remove it. On reflection, we see that the purpose in. Fig. 82.—Bot-fly of horse, female. After Bracy Clark
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectinsects, bookyear1902
