140 INSECTS OF ECONOMIC IMPORTANCE 



Willow and poplar borer '^ {Cryptorhynchus 



lapathi) 



Order — Coleoptera 



This is a beetle somewhat resembhng- the plum 

 curculio, but much larger, that is becoming a seri- 

 ous menace to poplar and willow trees both in the 

 nursery and on the lawn. The larv?e bore through 

 the wood finally causing the death of the tree. The 

 presence of the larvae is indicated by the appearance 

 of sawdust and particles of excrement thrown out- 

 side; the yellowish eggs are laid, each in a cavity 

 dug in the bark ; it hatches in 2 or 3 weeks and the 

 partly grown grub passes the winter just beneath 

 the outer bark and completes its growth the next 

 spring, the adult beetles appearing during the lat- 

 ter part of July ; there is one generation. 



Control — Apply an emulsion of carbolineum 

 avenarius to the trunks of trees to a height of 4 or 5 

 feet from ground; to make emulsion, dissolve i 

 pound of sodium carbonate in i quart of hot water 

 and add i quart of the carbolineum ; stir vigorously 

 and take i part to 2 parts of water. 



Hickory bark-borer"^ (Scolyfus quadrispinosus) 

 Order — Coleoptera 



The adult is a small brown or black beetle about 

 one-fifth of an inch long; the leaves wilt and twigs 

 die in midsummer and the bark will be found full 

 of small shotlike holes through which the beetles 

 have emerged; it is a serious pest to hickory trees. 



The beetles appear last of June to last of July; 

 they bore in young twigs, terminal buds and green 

 nuts; females make galleries just under bark in 

 sapwood and lay eggs in niches along the sides ; lar- 



6 Matheson— Cornell Univ. Expt. Stat., Bull. 388. 



^ Felt — Insects Afifecting Park and Woodland Trees, Vol. I, p. 275. 



