336 STATE BOARD OF AGRICULTURE. 



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. 



AFFECTING THE FOLIAGE. 



The Pear-leaf Blister-mite. {Phytoptus pyri.) 



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 

 becomes firmer in texture, the patches become darker, finally appearing black 

 and corky. A thin slice through such a thickened, corky patch, shows, under 

 the microscope, a cavity connecting with the outside 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 

 consequent injury to the foliage. Sometimes they form galls in the young fruit 

 as well. Often times the foliage falls, and the fruit fails to amount to anything. 

 The mites pass the winter tucked away under the bud scales. 



REMEDIES. 



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. 



The Pear Slug. (Eriocampoides Limacina.) 



Just before the time that cherries ripen, one is likely to find the foliage eaten, 

 or rather skeletonized on the upper side, so that only the larger veins remain. A 

 closer search reveals sticky, slug-like larvae about half an inch long, dark, dirty 

 green in color and. shaped like small clubs, broad just behind the head but taper- 

 ing to a slender tail. There is sometimes a later brood in August, but the first 

 brood does the most damage. These disgusting little slugs work on cherry, plum 

 and quince. The egg is laid on the under side of the leaf, under the epidermis 

 or skin. This is done quite early in the season but the larvae usually escape 

 detection until they are well grown. When full grown, these little "slugs" burrow 



Fig. 60. — Pear slug from Saunders. Insects Injurious to Fruits. 



into the soil and make little cells in which they pass the pupal stage, emerging, 

 after a time, as black, four-winged insects resembling flies, but really belonging 

 to the order of wasps. Each Is provided with a small saw-like apparatus under 

 the abdomen for the purpose of sawing a little pocket in the leaf in which to 

 deposit an egg. Hence the name of saw-fly is applied to the insects of this class. 

 This insect often causes a large part of the foliage to fall prematurely. 



KEIIEDIES. 



None of our fruit insects are easier to control than the pear and cherry slug. 

 Dry-slaked lime will kill many of them if merely dusted on, the sticky surface 

 of the slug causing the dust to adhere in such quantities as to cause death. Helle- 

 bore applied either dry or steeped in water will kill them. The arsenites are 



