376 



HYLESINUS TRIFOLII. CLOVER ROOT BORER. 



This insect has long been known as a not very common insect 

 of Germany in Europe. Miiller, as shown by the name, re- 

 garded it as an enemy of the clover, while Schmitt thought that 

 it attacked such plants as were already enfeebled, and was not a 

 serious injury. In 1878 the beetle attacked this valuable 'plant 

 in northwestern New York, and the fact that it injured very se- 

 riously the clover of that region proves tha.t Miiller was correct 

 and Schmitt wrong. 



Prof. Eiley investigated the habits of the insect, which he 

 found very destructive to the clover in Yates, Ontario and Seneca 

 counties. He described it under the name Hylesinus trif olii, or 

 Clover-root Borer, and pointed out the fact that it is much like 

 one of our common bark beetles, Hylesinus opaculus Lee., which 

 is often found just under the bark of ash and elm trees. 

 While much like the elm bark beetle, it is not only a different 

 species, but is placed in a different genus, Hylastes by Leconte 

 and Horn, and by European Coleopterists. 



xn| The family to which it belongs, Sco- 



|g lytidae, is represented by numerous 

 MB species, usually called bark beetles, 

 ^1 as they tunnel and sculpture various 

 evergreen and deciduous trees just 

 beneath the bark. It is often stated 

 that they attack enfeebled trees, 

 yet I have often found them indus- 

 trious and thriving on trees which 

 were in full strength and vigor. 



The insect is well represented in 

 Fig. 138, a showing the affected plant, 

 J the grub or larva, c the pupa, and d 

 the beetle or imago. The eggs are 

 FIG 138 whitish oval, the larva white, with 



yellow head. The length of larva is 3 m m (.12 of an inch) in 



