53 
Observations on Xylocopa and Lithurgus (Hymenoptera). 
BY W. M. GIFFARD. 
(Presented at meeting of January 6, 1921.) 
On December 22, Mr. Muir and I were at Waialua and 
observed the males of Lithurgus albofimbriatus swarming 
around the exit holes of Xylocopa varipuncta in part of an 
old tree-trunk, which had been utilized as a fence-post. It was 
quite evident that the males were waiting for the emergence of 
females. At the time no Xylocopa were noticed in the imme- 
diate neighborhood. Five days later, December 27, I again 
visited the place for the special purpose of cutting away a 
portion of the fence-post for further study and examination. 
The swarming of Lithurgus males, previously noticed, had en- 
tirely ceased. In a wait of one hour only two solitary speci- 
mens on the wing were seen in the immediate neighborhood 
(one male and one female), but Xylocopa were flying around 
the post, entering and emerging from their burrows in numbers. 
Bringing the cut sections to Honolulu and bagging them 
for better observation, emergence of both Lithurgus and Xlyo- 
copa began on the day following in large numbers, so that 
at the expiration of seven days nineteen males and twenty-three 
females of Lithurgus and twenty-two males and twenty-seven 
females of Xylocopa had emerged from two sections of post, 
ineasuring in all 214 feet by 8 inches in diameter. (Note—A 
large proportion of the Lithurgus and some of the Xylocopa 
were found to be attacked by large swarms of Acari. ‘These 
had massed themselves in swarms to the propodeum and an- 
terior segments of the abdomen. ) 
Upon opening the sections for further observation, the 
channels of both Lithurgus and Xylocopa were plainly seen, 
together with many old cocoons of the former and others con- 
taining pupae. The larvae of Lithurgus were not observed, nor 
were the pupae of Xylocopa seen. It is safe to say that quite 
a few more Lithurgus would have emerged had the splitting 
of the sections of the post been further postponed. There 
Proe. Haw. Ent. Soc., V, No. 1, October, 1922. 
