2370 Insects, 



the other poplar ; one allied to gnaphaliella, on Artemisia campestris ; and another 

 allied to Boyerella, which flies amongst Euonymus europaeus. (This last may be my 

 Demaryella, which is certainly allied to Boyerella, but I am not aware that it frequents 

 the spindle-tree). In Argyresthia two new species have been discovered ; one allied 

 to dilectella, and frequenting juniper ; the other very much resembling fagetella, but 

 larger : this I have no doubt is our semitestacella, consequently the spiniella of Zel- 

 ler — which I have given as a synonyme for semitestacella (Zool. App. vi.) — is proba- 

 bly a species unknown to us. I thought the above information might give a useful 

 hint to some of your readers to examine, during the ensuing season, the plants above 

 mentioned, and thus lead to the discovery of these novelties. — Id. 



Observations on a mixed Colony of Halictus abdominalis {female, Melitta fulvocincta, 

 Kirby), H. morio, Andrena nigro-cenea and Sphecodes subquadratus. By Fredk. 

 Smith, Esq., Curator to the Entomological Society. 



About the middle of the month of April I met with a colony of Halictus abdomi- 

 nalis, at a short distance from my residence at Newington ; and this afforded me an 

 excellent opportunity of observing the habits of the species. The situation which the 

 colony occupied was a bare patch in a sloping sand-bank, about three yards in length 

 by one broad. In mixed community with Halictus was a colony of Andrena nigro- 

 amea, another of Halictus morio, and also one of Sphecodes subquadratus. The 

 latter genus being generally considered to be parasitic upon Halictus, I was ex- 

 tremely anxious, if possible, to satisfy myself whether this supposition is correct 

 or not, since I am not aware that any one has satisfactorily proved such to be the fact. 

 I have, in former observations upon Sphecodes, expressed an opinion against their pa- 

 rasitism, founded upon observations of my own ; and one of the most eminent Hy- 

 menopterists of the present day thus expresses himself : " The insects upon which 

 these are parasitical, the most careful research has not yet discovered." 



In my observations upon the colony, it may be readily supposed that I lost no 

 opportunity of carefully observing the operations of these bees ; yet, notwithstanding the 

 most careful watching, I could not detect, in a single instance, the supposed parasite 

 entering the burrows of Halictus : the burrows which Sphecodes entered were of a 

 size intermediate between those of H. abdominalis and those of H. morio ; in fact, 

 the head of the insect exactly fitted the mouth of the burrow, — and I do not think the 

 Halictus could possibly have entered them. I repeated my observations on several 

 occasions, on days when all the species were numerous, but with exactly the same 

 results. 



It occurred to me, one cloudy morning, that it would be an excellent opportunity 

 for digging out the bees : this I did with the greatest care, and in every instance, in 

 the burrows of Halictus, I found that bee the sole occupant. In the burrows into 

 which I had observed Sphecodes enter on previous occasions, I found in each a single 

 female, but no Halictus. The burrows of both insects were about six inches deep: 

 at the extremity of those of Halictus were four or five cells divergent from the per- 



