5 



trunks of young apple trees the larva^ fed till late in antumn and the 

 l)eetles were seen (in confinement) about the end of Fe1)ruary at rest 

 in their passages, wliich they left in Ayivll and May. (ioui-eau, writing 

 in 1861 says that larva^ get their growtli I)}' the middle of winter, pupate 

 the last of Ma}' and mature in Jiuie. It will he seen that th(^se two 

 authors had no conc^eption of more than a single generation annually. 

 Later writers have assumed the probability of a second generation. Prof. 

 F. M. Webster speaking of its occurrence in central Ohio says "the 

 species is double-brooded."^ 



Observations conducted in the vincinity of the District of Columbia 

 have led the writer to the belief that there maybe a third generation pro- 

 duced in this latitude.- While the life cycle may be passed in as short 

 a space as four weeks, it would appear that the beetle is some time in 

 escaping from the wood and in feeding before completing the primarj^ 

 galleries and laj'ing its eggs. 



In the extreme .South, according to Mr. C. F. Baker, who has ob- 

 served this species at Auburn, Ala., it is almost impossible to trace anj^ 

 broods, owing to an apparent continuous breeding through the spring, 

 summer, and fall. As kite as December females were found in newly 

 foi-med brood chaml)ers. Larvae were also observed at this time and 

 the opinion was expressed that "the insect must pass the winter in 

 both egg and larval stages." 



PARASITIC AND OTHER ENEMIES. 



A much greater amount of damage from this bark-beetle would result 

 were it not held in check by a host of natvu'al enemies. In Europe two 

 hymenopterous parasites'' destroj^ it in great numbers. In the United 



I An. Kept. Ohio St. Hort. Soc. 1895-96, pp. 94-98. 



- From a twig of apple containing larv;e and procured by the writer in the 

 vicinity of the District of Cohniibia in September the earliest individuals of the 

 first generation were obtained May 1 of the year following. What we may con- 

 sider the second generation was issuing from the bark of i)lum the first week of 

 July. Larv;e were then present in greater abundance than at any other stage. 

 By the close of the month all but an extremely snuill percentage had issued as 

 beetles, a few struggling pupae and still fewer larvi^e being present under the 

 bark, which was then honeycombed by the rnultitudes of this insect which it 

 had harbored. Subsequently all the beetles escaped as the wood was cpiite dry 

 and no longer in condition for their maintenance. A third generation, if inc- 

 vious surmises are correct, was reared the first two weeks of Sei)t(Mnb('c from a 

 different lot of plum branches and was observed at the same ]K'riod in a peach 

 orchard in another locality. In the latt(>r place the beetles had evidently been 

 at work several days, having made holes suflicitMitly deep in the trees for their 

 complete concealment. Indications were that (his hypothetical third generation 

 made no attempt to breed but merely entered the peach trees for food and shel- 

 ter. Beetles could still be seen projecting from their burrows as late as the first 

 week of November, but no galleries of any kind were to be found. 



■^ Blaciis fiiscipcs (lOur., and Ptcrowalvs liimncidfifus Nees. 



