THE INSECT WORLD. 



233 



Fig. 240. 



Plum-curculio, Conotrachelus ?ienu- 

 phar. — a, larva ; b, pupa ; c, adult ; d, 

 beetle at work on a young plum, show- 

 ing a crescent mark. 



leaves of plum, peach, apricot, cherry, apple, and pear. When 

 the fruit has set and become of the size of a marble, the insect 

 makes a crescent-shaped slit, elevating a small flap from the sur- 

 rounding tissue, and in this it lays an egg. The latter hatches 

 in a few days, and the whitish, grub-like lar\^a bores at once to 

 the seed capsule, causing the 

 fruit to fall from the tree and rot 

 in the plum, peach, apricot, and 

 cherry, though, except in the 

 plum, this dropping is not uni- 

 versal. Apples and pears do not 

 drop as a result of curculio in- 

 jur}-, and, except in a few varie- 

 ties of apples, the larva is unable 

 to mature in the fruit remaining 

 on the tree. In apples and pears 

 that drop from other causes, the 

 larva develops freely. By mid- 

 summer, growth is complete, the 

 larv'se leave the now decayed 

 fruits and go underground to pupate, changing to the adult, or 

 beetle, form a short time thereafter. These go into hiding almost 

 immediately, and are not again seen until the spring following. 

 Remedial measures in this case have not proved entirely satisfac- 

 tory. The larva is beyond reach of all insecticides, and can be 

 destroyed only by persistent and thorough gathering of all fallen 

 fruit at intervals of a few days throughout the early part of the 

 summer. Chickens, turkeys, hogs, or sheep accomplish the same 

 purpose less completely and lessen if they do not prevent injury. 

 The beetles may be reached by spraying the trees before the buds 

 open with one of the arsenites, destroying them before they have 

 a chance to oviposit. Spraying may be continued after the fruit 

 has set, to kill the beetle while eating out its crescents. Some 

 part of the fruit is always injured, though a sufficiently large 

 percentage to pay for the insecticide application is usually saved. 

 Jarring the trees every day or two over a sheet or other recep- 

 tacle has been practised with good success, as the beetles drop 

 readily and lie quietly for some time, especially early in the day, 

 allowing themselves to be easily gathered up and destroyed. 



