ANNUAL REPORT, 1943-44 43 



Spray Coverage on Elm Logs in a Pile of Cordwood. (W. B. Becker.)^ 



Good spray coverage was obtained on elm logs in a pile of logs of cordwood 

 length by using a six-opening spray gun and a power sprayer giving 400 pounds 

 pressure. The pile sprayed included approximately six feet of a longer pile four 

 feet high. The spray was directed into the pile from the ends of the logs and from 

 the top of the pile. Approximately 12 to 15 gallons of a spray (Elgetol) which 

 left a visible deposit were applied. Immediate examination revealed that of 22 

 elm logs scattered throughout the pile, 12 were completely coated with spray, 

 9 were approximately 85 percent or more coated, whereas only one was as little 

 as half coated. The bark surfaces not coated were areas protected from the spray 

 stream by a branch stub or a cross stick in the pile, or where the surface of two 

 adjoining logs lay flat against each other. 



If satisfactory spray coverage can be obtained on logs inside a pile, it may facili- 

 tate the treatment of log piles to rfepel or kill the scolytids which are vectors of 

 the Dutch elm disease. 



Miscellaneous Biology Studies with Hylurgopinus rufipes (Eich.). (W. B. 

 Becker.) 



Beetle Emergence Throughout the Day. Although emergence of young adults 

 from logs fluctuated from day to day and from hour to hour, seemingly being 

 affected by the weather, by far the most of it occurred between mid-morning 

 and late afternoon. This was shown by emergence during 1936 and 1943 from 

 logs caged outdoors in partial shade. During 18 days in the late summer of 1936 

 the average emergence between the following hours (E. S. T.) was: 6-8 a.m. 1.9, 

 8-10 a.m. 2.8, 10-12 noon 33.9, 12-2 p.m. 69.9, 2-4 p.m. 31.4, 4-6 p.m. 8.4. 

 During the 18 overnight periods (6 p.m. to 6 a.m.) an average of only 2.8 beetles 

 emerged. During 15 days in the late summer of 1943 the average emergence 

 between the following hours was: 7:30-9:30 a.m. 3.66, 9:30-11:30 a.m. 22.53, 

 1 1 :30 a.m.-l :30 p.m. 63.06, 1 :30-3 :30 p.m. 53.06. During nine overnight periods 

 (3:30 p.m. to 7:30 a.m.) the average emergence was only 2.78 beetles 



Sex Ratio: The proportion of males to females was approximately one to one. 

 Both sexes started to emerge from logs at the same time in mid-summer and the 

 dail)- emergence of the sexes did not vary significantly throughout the season. 

 Between July 29 and August 26, 1938, 123 males and 99 females emerged from 

 some caged logs. Of 757 adults selected at random from specimens collected all 

 season, 383 were males and 374 were females. In 1943, 304 males and 309 females 

 emerged from small caged logs between August 4 and September 4. 



Some New Findings of Scolytus multistriatus Marsham in Massachusetts. 



(W. B. Becker.) One adult beetle was found in a log which had been exposed to 

 scolytid attack in 1942 at Amherst. 



Insect Pests of Wood and of Shade, Forest, and Ornamental Trees in Mass- 

 achusetts. (W. B. Becker.) During 1943 over 200 inquiries were received about 

 these insect pests. Ants, termites, powder post beetles, aphids, and secondar)- 

 tree-boring insects were received most frequently. 



Professor A. I. Bourne provided valuable assistance in planning this experiment. 



