154 Control of Parasites 



bodies. Their white grubs live in the wood of trees. They 

 are, as a rule, much less harmful than the bark-beetles, since 

 they are less prolific. Nevertheless, in young trees of pop- 

 lars, willows, chestnut, oak, ash, walnut, cherry, and apple, 

 the grubs, especially those which burrow in the roots, do 

 enough havoc to kill occasionally even large trees. 



The most obnoxious seems to be the Locust-borer, which 

 riddles young Black Locust trees until they die, or else under- 

 mines their stability; it also attacks walnut and hickory. 

 The brown to black beetles, striped and banded with golden 

 yellow and with a W on their wing-covers, gather in August 

 and early September on the flowers of goldenrod, where 

 they may be collected; they may also be collected as they 

 lay their eggs soon afterward in the crevices of the bark. 

 The larva issues the same fall and bores a quarter-inch hole 

 under the bark and upwards, the ejected wood dust dis- 

 closing its presence. 



Whitewashing, soaping, or covering with dendrolene, 

 to prevent the beetle from laying its eggs in August, besides 

 collecting the beetles, are the remedies for this and other 

 similar borers. 



The Oak-pruner and other twig-girdlers belong here. 

 They lay their eggs in a twig and then girdle the twig at some 

 distance below, so that it may die and be broken off by the 

 winds, the larva developing in the fallen twig on the ground. 



Flat- headed Wood-borers are large, broad, squarish beetles 

 of metallic colors, with short legs, the footless grubs recog- 

 nizable by the much broadened and flattened head and 

 front part. The grubs live in the wood of trees, making 

 burrows in the cambium, wood, or bark. The elliptic 

 form of the holes through which the larvae enter and the 

 young beetles escape is characteristic. These beetles are 

 chiefly injurious to deciduous trees — oak, beech, basswood, 



