DESTRUCTIVE INSECTS. 185 



other moist conditions cause a rapid decaying and a cracking 

 open of the infested fruit, as shown in Fig. 251. Through the 

 openings thus made the maggots emerge and enter the soil an 

 inch or two, where they make oval, silken cocoons, in which 

 they remain until spring, when they change to pupae, and 

 soon afterward to the adult flies or midges. 



The Lawrence variety of pear, which blooms early, seems 

 to be a favorite with the midge. 



The pest seems to be invulnerable to any insecticidal oper- 

 ation, which does not involve the loss of the fruit, until the 

 maggots leave the fruit and enter the ground. Where only a 

 few trees are infested, one could readily distinguish most of 

 the infested, misshapen fruits, and pick them off and destroy 

 them ; this should be done before May i5th to be effective. It 

 would pay in certain cases thus to destroy all the fruits on a 

 few trees for a season if an orchard could be thereby freed 

 from the pest. 



Experiments give considerable hope that many of the midge 

 maggots can be destroyed in loose sandy soils by an applica- 

 tion of kainit, at the rate of one thousand pounds to an acre, 

 about the middle of June. Other experiments on clay soils 

 indicate that such heavy applications of potash salts each year 

 injure the trees, and that thorough cultivation is far prefer- 

 able to the fertilizers. 



The Plum Curculio (Conotrachelus nenuphar}. This native 

 American insect is the cause of most " wormy " plums, prunes, 

 apricots, peaches, nectarines, and cherries. It is usually by 

 ' far the most destructive insect with which growers of these 

 fruits have to contend, as it often ruins the whole crop unless 

 promptly checked. It also breeds in apples and pears, but 

 not so freely as in the stone-fruits; during years when the 

 latter fruits are a light crop it often becomes a serious pest on 

 apples. The insect is widely distributed throughout the coun- 

 try east of the Rocky Mountains, but has not yet invaded the 

 Pacific Coast States. 



The adult insect (Fig. 252) belongs to a family of beetles 

 known as curculios, weevils, or snout-beetles. It is a small, 

 rough, blackish beetle, about one-fifth of an inch long, with a 

 black, shining hump on the middle .of each wing-case, and 

 behind this a band of dull ochre-yellow color, with some 



