When these caterpillars feed on the leaves of wild cherry they are doing no damage to an orchard. Therefore, when the tents appear on wild cherry trees have we any right to destroy them? _Answer._ The wise and careful farmer does not allow wild cherry trees to grow along his fences if they will become breeding places for insect enemies which will next year attack his orchards. [Illustration: _Fig. 149. The Curious History of a Tent Caterpillar. a, The masses of eggs on the twigs of an apple tree. b, The eggs enlarged. c, A full grown caterpillar. d, Cocoons. e, The moth, or adult insect._] LEAFLET XX. MOSQUITOES.[26] BY MARY ROGERS MILLER. "Nature-Study is learning those things in nature that are best worth knowing, to the end of doing those things that make life most worth living." --PROFESSOR HODGE in _Nature-Study and Life_. [26] Home Nature-Study Course, Vol. IV, No. 23, May, 1902. [Illustration] Spite of all the efforts of scientists and nature-students to popularize the mosquito, its reputation as a public nuisance is as well sustained as ever, and it seems destined to remain as unpopular as were its ancestors. There is no doubt that these creatures "abound" and that "they are great annoyances to both man and animals," as Dr. Howard tells us in "The Insect Book;" but he has laid a new and even more deadly sin at their door in stating, as he does in no uncertain terms, that "they are active agents in the transfer of disease." There seems to be no escape from the attention of these persistent "imps o' evil." Though we travel to far Alaska or to icy Greenland we cannot be free. Since we are doomed to existence in the same world with the mosquito it behooves us to discover, if possible, some way to turn the creature to account for our entertainment or instruction. Forget for the moment that you despise mosquitoes, and let us study their ways. By making its life history the subject of some of our lessons we may at least learn how the mosquito lives and develops; and later we can turn this knowledge to practical account. Since for many generations these creatures have made the human race the subject of insistent study, it is no more than fair that the tables should be turned! You are not good nature-students until you have recognized and overcome your prejudices. You read the life history of the rabbit and you think you hate its enemies. You watch a family of foxes with their cunning ways, and the mother's care for her young and you cannot help sympathizing with them in their struggle for existence. Every creature in its turn becomes interesting to you when you find yourself wondering about how it makes its home, rears its young, and gets its food. As you get nearer to nature you will cease to feel any pride in the fact that you "hate" snakes, mosquitoes, and all such "varmints." Indeed that hatred, born of ignorance, will have given place to sympathy and interest. You have a new point of view.