1919] Blackman — Notes on Forest Insects 93 



and Orthotomicus (Ips) coelatus Eich. These stumps were still 

 green and sappy and pitch exuded from all of the burrows, while 

 those of D. valens had the characteristic pitch tubes. The bur- 

 rows of Hylurgops were in all stages from those recently started to 

 completed burrows containing recently hatched larvae. In no case 

 had these extended their burrows more than two centimeters, and 

 in most instances eggs or larvae just hatched occupied the egg- 

 grooves in the sides of the galleries. The pieces of bark on being 

 removed contained such good specimens of the early brood-bur- 

 rows that a considerable number of them were taken to camp, 

 wrapped in old newspapers, and shipped to the laboratory, no 

 effort being made either to remove the brood or to preserve it from 

 injury although specimens were taken. The boxes containing 

 these bark specimens were not unpacked until September 2, when 

 the writer was surprised to find large numbers of adults of the 

 new generation burrowing into the bark or feeding upon its inner 

 surface which was by then quite dry. These undoubtedly had 

 developed from the young larvae and eggs present on June 18. 

 That the eggs then present had later hatched was readily estab- 

 lished by an examination of the egg-grooves. 



On October 20, 1916, numerous young adults found in their 

 parent burrows, were brought into the laboratory and 46 of these 

 placed in a celluloid box securely fastened to the rough bark of a 

 section of the trunk of a recently cut, dying pine. Most of the 

 beetles wandered about for the next few days in their enclosure, 

 seeking a means of escape, some of them stridulating frequently. 

 These latter were males. However, before the following morning 

 several females had started burrows through the bark and within 

 two days were observed to be casting out white chips, showing that 

 they had begun to groove the sap wood. By October 25, all of the 

 beetles except four had disappeared beneath the bark, many of 

 them utilizing the entrance holes made by the first workers. One 

 month later (November 25) a piece of bark near one of the entrance 

 holes was carefully removed and eggs and young larvae were found 

 in considerable numbers. Some of the larvae had burrowed for a 

 distance of 35 mm. through the inner bark and were probably less 

 than two weeks old. The eggs examined were oval in shape, 

 slightly less than 1 mm. in their longest diameter, and contained 

 well formed larvae which hatched two days later. 



