ENTOMOLOGY 47 



legs. When disturbed, they jump and fly away, sometimes being so 

 numerous as to appear to fly in droves. Several broods are reared in 

 one season. 



Spray with weak kerosene-emulsion while the insects are in the 

 immature condition in late May and early June. At this time they 

 cannot fly. Any of the strong winter washes should prove all right 

 as they pass the winter hidden away in cracks and crannies and 

 under the buds. Clean culture will also prove useful, for judging 

 from allied species, many adults will be found to pass the winter in 

 rubbish. 



The Pear-Leaf Blister-Mite. About the time when the young 

 pear leaves become full grown, and while they are still tender, they 

 sometimes are disfigured by pinkish, thickened patches, involving a 

 portion of the leaf, or occasionally the entire leaf. As the leaf be- 

 comes firmer in texture, the patches become darker, finally appear- 

 ing black and corky. A thin slice through such a thickened, corky 

 patch, shows, under the microscope, a cavity connecting with the out- 

 side by a small opening. In the cavity may sometimes be found the 

 cause of the mischief; minute, white mites, elongate in form, and so 

 small that a glass is required in order to be sure of them. These little 

 mites are the cause of the thickened growth or gall, and the conse- 

 quent injury to the foliage. Sometimes they form galls in the young 

 fruit as well. Oftentimes the foliage falls, and the fruit fails to 

 amount to anything. The mites pass the winter tucked away under 

 the bud scales. 



As the mites are concealed, during the growing season, in the 

 galls of the leaves, it is useless to spray during that period. In the 

 winter, however, they may be killed by a spray of strong kerosene- 

 emulsion applied while the buds are dormant, or at any rate before 

 they open in the spring. (Bui. 24 Mich. E. S.) 



The Pear Slug. The damage to the foliage of the pear, cherry, 

 plum, and allied trees from the slimy slug-worm is familiar to every 

 fruit grower. Two or three generations of these slug-worms, or slugs, 

 as they are also termed, appear during the summer and frequently in 

 such extraordinary numbers, with the later broods, that the leaves of 

 the attacked plants turn brown, die, and fall to the ground in mid- 

 summer, and the new growth of foliage which is afterward thrown 

 out is often similarly destroyed. The slug-fly is a small, glossy black 

 insect, considerably less in size than the house fly, measuring only 

 about one-fifth of an inch in length. The wings, which are four in 

 number, are transparent, iridescent, and have a smoky band across 

 the middle, which varies in intensity in different specimens. It be- 

 longs to the family commonly termed saw-flies on account of the 

 saw-like instrument or ovipositor with which the female insect places 

 its eggs in the leaves or other soft parts of the plant. At first it is 

 clear or free from slime and in color nearly white, except the yellow- 

 ish-brown head; but almost immediately the slimy or gluey olive-col- 

 ored liquid begins to exude over its entire body, giving it the appear- 

 ance of a minute slug, or soft snail, from which it getn its name. 

 Its head is dark brown, appearing black under the slime, and the 



