No. 4.] SHADE-TREE INSECT PROBLEM. 95 



Willows and poplars are much in demand in planting 

 schemes for damp localities, or in places where rapid growth 

 is desired. As trees of this class are so well adapted for 

 such purposes, it is most unfortunate that they are becoming 

 more and more subject to damage by the imported willow 

 weevil (Cryptorhynchus lapctthi^ Linn.). This small snout 

 beetle of the great family of weevils has been known for 

 generations in Europe as a pest of the basket willow and of 

 alder plantations. Its food plants there include about all 

 the willows, poplars, many alders and a few birches. It 

 occurs from southern France up into the highest mountains 

 of Switzerland, where it breeds in the green alder. Doubt- 

 less it was brought to this country in nursery stock ; cer- 

 tainly its general occurrence in the nurseries in this State 

 would give force to this opinion. It has now spread at least 

 from Brooklyn to Portland and westward to Buffalo and 

 points in Ohio. 



The mature beetle is of a dark-brown color, with a con- 

 spicuous white marking at the posterior part of the body, 

 and with smaller white markings on the anterior part of the 

 wing covers. With its long snout it drills holes into the 

 bark just beneath the leaf scars, and inserts its eggs, from 

 one to four in a place, each in a separate chamber, which is 

 afterwards closed with bark dust. This egg laying, as the 

 writer has observed it, takes place late in the summer ; but 

 in nearly every case the eggs hatch and the larvae feed in the 

 bark for a few weeks before hibernating. The insects at 

 this time are so minute in size that they can be found only 

 by diligent search. With the coming of spring, however, 

 they extend their burrows in the bark, breaking through the 

 surface at frequent intervals, and then in about a fortnight 

 sink into the sapwood and finally to the heart of the tree. 

 The growth of the white, yellow-headed larva is something 

 phenomenal, especially in young trees. By the first week 

 in July the larvae are fully grown, and carefully enlarge 

 their burrows downward to the surface of the bark, throw- 

 ing out large quantities of white chips, which are an excel- 

 lent indication of the presence of the insect. The sap which 

 oozes from the burrows is also a characteristic sign of the 



