CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 329 



CCC. Characters similar to CC, but mesosternum is deeply emarginate. 

 Claws simple and divergent; ventral segments 2-4, equal; sutures 

 straight. — Cryptorhynchus. 



Poplar and Willow Borer {Cryptorhynchus lapaihi Linn.). — (Consult 

 Cornell Bull. 388.) An introduced beetle from Europe, infesting 

 poplars, willows and alders from N. Dakota to Maine and Quebec. 



Adult. — A sooty-brown snout-beetle, 3^^ inch long, spotted with 

 grey; beak curved and as long as head and thorax; body thick and 

 punctured on the surface; ends of wing-covers, sides of pro thorax and 

 two oblique bands on wing-cover light grey. After emerging the adult 

 feeds by puncturing the bark of young tender shoots. Mating and egg- 

 laying occur 10-14 days after emergence. July-October. 



Eggs. — Cream colored, oval; laid in holes made in bark of branches 

 2-4 years old. Hatch in 18-25 days, in August-November. 



Larva. — Burrows in the cambium until nearly full grown, then in the 

 wood; a soft yellowish fleshy cylindrical footless grub with a pale 

 brown head and darker mouth-parts; 3^^ inch long. Mature in June. 



Pupa. — When ready for pupation the larva enters older wood and 

 makes a pupal chamber (i to several inches long) which is filled with 

 fras. Pupa whitish-yellow, with brown spiracles; small spines scattered 

 over dorsal surface and a pair of strong incurving brown spines at tip 

 of abdomen. Duration ia-i8 days. 



Control. — Spray trees with arsenate of lead every fortnight between 

 July 15th and September ist; apply carbolineum to nursery stock in 

 early spring; cut out grubs from moderately infested trees; cut down 

 and burn badly infested trees during winter or before July ist. 



Plum Curculio (Conotrackelus nenuphar Herbst.). — This snout- 

 beetle is a widely distributed native insect and is a serious pest of 

 plums, pears, apples and peaches, cherries and apricots on account of 

 its punctures and the dropping of infested fruit (Fig. 212). 



Adult. — A stout snout-beetle, }>^ inch long, brownish, and marked 

 with grey and black; four black-ridged tubercles on the wing-cover; 

 hibernates and emerges just before the fruit buds open. Feeds 

 to some extent on the buds, but mostly on the young fruit as soon 

 as it is set. Female begins to lay eggs in the young fruit as soon as it is 

 formed. Lives about 2 months, laying 100-300 eggs. Makes two 

 kinds of punctures in the fruit: egg-punctures and feeding-punctures. 



