OF WASHINGTON. 25 



S o'clock, the sky is entirely overcast with heavy, black 

 clouds ; the air is extremely sultry and filled with a mist-like 

 fog. To the uninitiated it would appear that a heavy downpour 

 of rain was about to take place, but between 8 and 9 o'clock the 

 gulf breeze springs up, the clouds are dissipated as if by magic, 

 and the brightest sunshine prevails for the rest of the day. 



During my stay at San Diego, Duval Co., it was my custom 

 to go into the field every day at half past 7 o'clock, and during 

 these cloudy mornings at the end of April and during the first 

 three weeks of May I had ample opportunity of observing sleep 

 ing specimens of the two Apidae mentioned above. At this hour 

 many butterflies, beetles, flies, etc., were on the wing, but the 

 light was evidently not strong enough, or the atmosphere too 

 heavy and moist, to arouse from their sleep these little bees. 

 Scattered through the chaparral (brush) which surrounds the 

 town of San Diego are numerous dead bushes, most of them 

 being Celtis pallida. It is on the thinnest, outermost twigs and 

 more particularly on the stout thorns with which this shrub is 

 liberally provided that single sleeping specimens of these bees 

 are found. Their position is uniform : the twig or thorn is 

 grasped tightly with all of the six legs, and, in addition, the 

 mandibles are widely opened and with their tips firmly inserted 

 into the wood. It requires some force, comparatively speaking, 

 to dislodge the bees from their position. 



As stated above, I have seen in print records of a similar 

 attitude of sleeping bees, and I would not have presented this 

 note but for the following additional observation : On the very 

 first day I found that there are certain dead shrubs which serve 

 as sleeping quarters for a multitude of the bees. In the course 

 of time I discovered within a short distance four shrubs (or dwarf 

 trees) upon each of which from 50 to 70 specimens of the sleep 

 ing bees could be seen every morning, and several other shrubs 

 which harbored a smaller number of specimens, with plenty of 

 room for more. Here my third species, the Sphegid Coloptera 

 -wright ii, comes in. It was always on the sleeping trees in com 

 pany with the bees, but not so numerous as the latter. I never 

 saw it asleep at the hour I made these observations, but the speci 

 mens were, like watchmen, slowly walking up and down the 

 twigs, over the bodies of the sleeping bees, carefully and deliber 

 ately touching and examining with their antennas the bees, as if 

 trying to arouse them from their sleep. If I had been on the 

 spot at an earlier hour, or after dark hi the evening, I would, no 

 doubt, have ascertained also the sleeping habit of the Coloptera. 

 A well-frequented sleeping tree presents a very striking and ex 

 ceedingly pretty sight, which I never wearied of observing day 

 after day. 



