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 larve enter and the 
young beetles escape is characteristic. These beetles are 
chiefly injurious to deciduous trees — oak, beech, basswood, 
