June 9, 1897.] 



Garden and Forest. 



225 



feed on the tender tissues. Fig. 1 is from a photograph 

 made April 24th, showing a pistol-case-bearer, of natural 

 size, at work on an opening Apple-leaf bud. After the pho- 

 tograph was made the case-bearer was removed, showing 

 a small round hole just large enough to admit the insect's 



Fig. 29. — Young Pistol-case-bearer on opening leaf-bud 



five decimeters. 



an Apple, enlarged nearly 



body. This hole reached well toward the interior of the 

 bud, where a cavity was evidently being made in conse- 

 quence of the devouring little insect's appetite. While 

 feeding in this way the caterpillar did not lose hold of its 

 protecting case, but apparently held it in position by the 

 posterior segments of its body. It does not appear to be 

 the habit of the caterpillar to leave its case, but to thrust its 

 body out as far as possible without losing hold of this 

 protecting retreat. 



Fig. 2 is from a photograph made April 29th and shows 

 the insect enlarged about four times. It will be noticed 

 that the case is not quite the same shape as the one shown 

 in Fig. 1. As the case-bearers enlarge they change the 

 shape of their cases slightly, and also lengthen them as the 

 increasing size of their bodies demands. When of full size 

 they measure about one-fourth of an inch in length. The 

 twig in the figure was cut from a three-year-old Apple-tree 

 in the nursery row. The case-bearer was working on the 

 interior of the bud at the base of the opening leaves. When 



the leaves have become well expanded the case-bearers 

 attack these also, eating away the soft parts at first, but 

 finally eating holes clear through them. Later in the sea- 

 son, when they have become larger and stronger, they 

 readily devour nearly the whole leaf with the exception 

 of the midrib and larger veins. 



Although the case-bearers do serious injury in 

 thus feeding on the leaves, they probably do as 

 much or more harm by attacking the opening 

 flower-buds and the fully expanded flowers them- 

 selves. They feed on the interior of the flower-buds, 

 eating away the tender tissues, destroying the life 

 of the buds and thus preventing the development 

 of the fruit. In the same way the flowers are de- 

 stroyed, both the petals and essential organs being 

 devoured. The fruit is also sometimes attacked, 

 the case-bearers boring through the skin and feed- 

 ing on the tissues just beneath. This causes the 

 apple to become more or less deformed, according 

 to the extent of the injury. Young pears also 

 suffer in this way. 



During the middle or latter part of May the case- 

 bearers are ready to pupate, and accordingly mi- 

 grate to the twigs, where each larva attaches its 

 case firmly and in a nearly upright position to the 

 bark. They then manage to turn around in then- 

 cases so as to bring the head in the opposite direc- 

 tion from its original one. While in this position 

 the change to the pupa takes place. About the 

 middle of June the mature insects, small gray 

 moths, come forth, making their exit by means of 

 a slit in the upper end of the case. Egg-laying 

 soon begins, the eggs being deposited on the under 

 side of the leaves. As soon as hatched, the young 

 case-bearers begin to construct their cases, making 

 them of excrement and silk, and begin to eat small 

 round holes into the interior of the leaf. Before 

 winter sets in they migrate to the twigs, where 

 their cases are firmly attached to the bark in a 

 nearly upright position, to remain until spring 

 comes again. 



This is in brief the life-history of this interesting 

 insect. We have discussed it more in detail in 

 Bulletin No. 122 of this station. Although appar- 

 ently so well protected, many of the case-bearers 

 succumb to the attacks of parasites. We have bred 

 three species from insects kept in the laboratory. 



As to remedial measures, theoretically the case- 

 bearers can be controlled by spraying the trees 

 with Paris green just before the leaf-buds begin to 

 swell, so that the first meal of the newly awakened 

 insect will be a poisoned one. Our experiments 

 last year showed that an application of Paris green 

 made at this time, using one pound to 1 50 gallons of 

 water, aided materially in holding the pest in check. 

 Two applications of the poison were made later in 

 the season, however, one just as the young case- bearers were 

 observed eating holes clear through the leaves, and another 

 soon after the petals had fallen. These three applications 

 proved successful in keeping a number of Apple-trees 

 which had been badly infested comparatively free. 



Although apparently preferring the Apple, this case- 

 bearer attacks the Pear and Quince. 



A closely allied species is the cigar-case-bearer, which 

 has many similar habits, but which can be readily distin- 

 guished from the shape of its case. 



New York Agric'l Eacperim't Station, Geneva, N. V. 



J*. //. Lowe. 



Cultural Department. 



Choice Hardy Plants. 



T N a slightly shaded, cool, moist and sheltered position .1 bed 

 *■ of Gentiana acaulis is now freely shewing us beautiful 

 flowers. The bright dark blue flowers are large, considering 

 the size of the plants. They are campanulate, but not droop- 



