28 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



AugiivSt to find these gashes and to cut out the small grubs ia the bark 

 underneath, at a time when they have not descended deep into the tree. 

 An observant and intelligent gardener could easily prevent further 

 damage from such a cause. 



One of the most formidable and deadly borers of the oak, from Maine 

 to California and Texas, is the caterpillar of the Carpenter moth. In 

 Europe a similar borer is dealt with in the following ways, according to 

 different writers quoted by Miss Ormerod in her "Manual of Injurious 

 Insects." A wire thrust into the "mine" or hole may destroy them. 

 Paraffiue injected by a sharp-nozzled syringe with as much force as pos- 

 sible into the holes where the caterpillars are working is a good remedy, 

 also any oily or soapy mixture (kerosene injections might injure the 

 tree more than the borer). The flames of sulphur blown into the hole 

 might be of use. " Where a tree is much infested, it is the best plan 

 to cut it down, split it, and destroy the caterpillars within. As many as 

 sixty or more caterpillars may be taken from one tree, and when in this 

 state it will never thoroughly recover, and it becomes a center to attract 

 further attack, as well as one to spread infection." 



As preventive measures, to prevent oviposition, the lower part of the 

 trunk should be washed with whale oil soap of the consistency of thick 

 paint.. This should be done at or about the time the moth lays her eggs, 

 viz, as early as April and May in Texas, and in June and July in the 

 Northern States. 



These suggestions will also apply to the Sesiau borers of the maple, 

 ash, etc. 



Prevention and remedies against Timber-beetles and Bark-borers. — The 

 family of bark-borers (iSGolytidce) include those which live in the bark 

 and those which descend into the wood, the latter often being called 

 timber-beetles. We have given in this work some of the known facts 

 regarding their habits, which are very curious. Eichhoff's excellent 

 work in German on European bark-beetles is replete with fresh obser- 

 vations on these beetles. We may here draw attention to what Eich- 

 hoff says concerning some causes of the undue increase of these insects, 

 and their sudden appearance in places not before frequented by them. 



The chief factors in the growth of bark-beetles are good weather and 

 sufficient nourishment. An uninterrupted dry, and hence hot, summer, 

 checks the growth of the larva, and retards the speedy development 

 and more often prevents a repetition of another brood, than an unin- 

 terrupted wet and cold spring and summer. Hence, on account of great 

 heat and drought many trees survive which would otherwise be injured 

 by the later brood of bark-beetles. The most favorable conditions for 

 the increase of bark-beetles are doubtless a warm early spring and a 

 warm summer, with frequent rains and a long, mild autumn. 



Other circumstances, says Eichhoff, favorable to the increase of bark- 

 beetles, are strong winds, snow, frosts, forest fires, the devastation 

 wrought by caterpillars, whereby the trees are more or less decorti- 



