Notes on the Life History of Dinapate 

 wrightii Horn. (Col.)" 



By Roy E. Campbell, U. S. Bureau of Entomology, Alhambra, Cal. 



In May, 1916, Mr. J. 0. Martin, of Pasadena, after consid- 

 erable tedious scouting, discovered a log of the Washington Palm 

 (Washingtonia plifera) in Palm Canyon, on the Northwestern 

 border of the Colorado Desert, which contained partially-grown 

 larvae of Dinapate wrightii. Mr. Martin could hear more larvae 

 at work in the log, and decided to mark it and wait until the follow- 

 ing spring for further action. In 1917 he returned to Palm Can- 

 yon and sawed out several pieces from the fallen log, carried them 

 down the canyon to his automobile (a feat which was discovered 

 a little later by the writer to be quite laborious) and transported 

 them to Pasadena.^ 



At the suggestion of Dr. F. H. Chittenden, the writer got into 

 communication with Mr. Martin and received directions to locate 

 the remaining 10 feet of the infested log. On May 19, 1917, the 

 writer went to Palm Springs and duplicated Mr. Martin's actions, 

 except that the scouting was unnecessary. The logs were placed 

 in a wire cage, in Alhambra, and closely watched. Mr. Martin's 

 efforts were rewarded by the appearance of the first beetle on 

 August 3, and emergences continued until thirty-one had appeared 

 by September 17. In the writer's cage 3 adults appeared in the 

 latter part of July, and 2 in August. 



When the sections were sawed from the log, a few larvae were 

 disclosed, some practically full-grown, while others were quite 

 apparently immature, indicating the possibility of two broods. 

 Also after the emergence of the beetles in 1917, larvae could still 

 be heard at work within the log. 



On April 15, 1918, one piece of the log which had been trans- 

 ported to Alhambra, was cut up and examined. Nine larvae were 

 found, four of which were full-grown, and the rest not over half- 

 grown. These larvae were sent to Dr. Chittenden. Also one dead 

 adult female, which had failed to make its way out of the log, 

 was uncovered. The emergences of adults for that year from the 

 remaining piece of log were as follows : 



" Bull. Brooklyn Ent. Soc. Vol. XII No. 5, pp. 107-110, December, 1917. 



*Since tils paper was piesenled for publication, an article by Dr. J. A. Comstock on "A 

 Giant Palm-Borins Beetle" appeared in the March, 1922. Bulletin of the Southern California 

 Academa of Sciences (Vol. XXI. PaTt I). Besides giving many of his observations, it reviews 

 the literature on this interesting beetle. 



