Midges are small or minute flies; swarms of them are commonly seen in damp localities in the summer. FLIES. Horseflies are unusually abundant in the neighborhood of ponds and streams. The Robber Flies, or bee-killers, are the hawks of the insect world, preying upon their victims on the wing. In flying an insect is likely to become the victim to their sharp little dagger, which they carry in their beak. It is said that they will frequent a favorite position near a beehive and make frequent trips back and forth, and hundreds of empty bodies of bees are found beneath this perch. The Dancefly is so called because of the up-and-down movement which they make in their swarms. The Housefly. These insects are highly injurious to human beings because of their agency in spreading germs of such diseases as typhoid fever and Asiatic cholera. It has been discovered recently that germs of infantile paralysis are conveyed by the housefly. THYSANOPTERA. To this order belong very small insects known as "thrips." They are found in large numbers in flowers and in the heads of grain, chrysanthemum, hydrangea, orange-blossom, cabbage leaf, cauliflower, squash, turnips and other plants. HEMIPTERA includes plant-lice, scale insects and bugs proper. One entomologist says: "If anything were to exterminate the destroyers of hemiptera, we, ourselves, would probably be starved in the course of a few months," so harmful are they to vegetation. One of the best-known insects of this order is the cicada or harvestfly, popularly but wrongly called the "locust," the term "locust" belonging rightfully to the long-horned grasshoppers. The body of the cicada is large with a blunt head. At the end of July and early in August its song may be heard in the treetops. The queer-shaped treehoppers also belong to this order. When they are resting upon a twig, it is difficult, except upon close examination, to distinguish them from a thorn or a natural protuberance of the wood. The Spittle Insects. After hatching from the egg the young insects live in little frothy masses like spittle on the stems of plants and grasses. Scale Insects. Many of the members of this family are very injurious to fruit trees and other trees. They feed upon the sap. The Oyster-shell Bark Louse is found particularly upon apple and pear trees. [Illustration: SCALE INSECTS.] Plant Lice. These insects prey upon cultivated plants. Huxley computed that the uninterrupted breeding of ten generations of plant lice from the single insect would produce a bulk equal to the population of the Chinese Empire, 500,000,000 of human beings. We have already spoken of the relations between ants and plant lice; they are often called "Ant Cows" because of the ant's habit of milking them for the juices which they exhume. THE TRUE BUGS.