March 1894.] 



PSYCHE. 



45 



found ill I'otteii wood was provisioned 

 with blue-bottle flies and from which 

 he reared Crabro vagus. 



Our native species of Crabro are 

 numerous but very little is recorded 

 respecting their habits. Packard states 

 that Crabro sex-niactilatzis Say ., accord- 

 ing to Dr. T. W. Harris' ms. notes, 

 was seen June 10 by Mr. Leonard of 

 Dublin, N. H., burrowing in decaying 

 wood, while Crabro singularis Smith 

 svas discovered hy Mr. C. A. -Shurtlefl' 

 boring in a post. 



Mr. Wm. Couper, in an article en- 

 titled "Nest of Crabro sex-maculatns 

 .Sav" published in Can. ent., i (1S69). 

 p. 77, figures and describes the nest of 

 a bee that was identified for him by 

 Dr. Packard as this species, but which 

 clearly must be a mistake, due un- 

 doubtedly to Mr. Couper sending the 

 Doctor the wrong insect as the maker 

 of the nest. 



The nest was made in tops of rasp- 

 berry canes, the pith having been ex- 

 tracted by the bee and the interior then 

 utilized for the reception of the cells, 

 which were filled (according to Mr. 

 Couper) with pollen. Mr. Couper 

 found the eggs and the larvae in various 

 stages of development, but tells us 

 nothing about their further develop- 

 ment, or whether he succeeded in rear- 

 ing the imago. 



Altogether the article is very unsatis- 

 factory and I do not believe it to be, 

 what it is represented, the nest of 

 Crabro sex-maculattis Say, which is 

 a fossorial wasp and not a bee. 



.Species in the genus Rhopalnm 



Kirby are said to bore into the stems of 

 pithy plants and to prey upon spiders 

 and Aphides. 



The genus Trypoxylon, which prob- 

 ably represents a distinct family, has 

 similar habits, although most of the 

 species are "lazy fellows" seldom tak- 

 ing the trouble to build a nest for 

 themselves, preferring to "crib" one 

 from some other wasp, or then to utilize 

 an old deserted cell or then any hole or 

 crevice they can find, which is suitable 

 for them to Iniild their ceils for their 

 supplies. This peculiarity caused them 

 at one time to be considered parasitic. 



Walsh was the first to record the 

 habits of Trypoxylon albitarse which 

 usually selects the deserted cells of a 

 mud-dauber (Pelopaeus) in which to 

 nidificate, provisioning its cells with 

 spiders. I can confirm this statement 

 of Walsh's from personal observations 

 as I have not only obtained them from 

 the old cells of Pelopaeus but also from 

 those ot Cka/ybion caeriileutn. I have 

 also bred T. clavatitni Say irom the 

 same mud-dauber's cell. 



Trypoxylon caritiifrons Fox, T. 

 coUiuuiii .Smith, and T. albopilosum 

 Fox, on the contrary, carry oft" Aphides 

 with which to provision their cells. 

 The first, whicli is the smallest species, 

 takes up its abode in the round holes 

 made by Scolytids in pine-timber, into 

 which I have seen them going carry- 

 ing ChaitopJiorits salicicola Monell, 

 obtained from a willow close by. This 

 species is parasitized hy an equally 

 small Chrysid, Chrysis verticalis 

 Pattn. The second I have seen carry. 



