THE ENTOMOLOGIST. 99 
“The bees which are included in this genus have hitherto 
been regarded as parasitic on those comprised in the genus 
Halictus ; and, indeed, many circumstances tend to support 
such a supposition. They are usually found burrowing, not 
ouly in similar situations, but forming mixed colonies. The 
females of both genera appear some time before the males, and 
in fact their economy is alike. St. Fargeau places them 
amongst his division of parasites, immediately following his 
exotic genus Rathymus, with which they have not the 
slightest affinity, their only resemblance being in the distri- 
bution of colours—black and red. The result of my observa- 
tion leads to the conclusion that no species of the Andrenidz 
is parasitic. The only apparent support of the theory of their 
parasitism is the absence of the usual pollinigerous organs. 
Such, however, is also the case in Prosopis, Ceratina, &c. In 
the year 1849 I discovered a mixed colony of Halictus abdo- 
minalis, Andrena nigro-wnea, Halictus Morio, Sphekodes 
subquadratus, and 8. Geoffroyellus: this being at a short 
distance from my house I had an opportunity of frequently 
observing their economy. My visits to the colony were 
frequent, and I made close observation on the proceedings of 
the bees; yet, notwithstanding, [ could not in a single 
instance detect the Sphekodes entering the burrows of 
Halictus. Those into which the former bee entered were of 
a smaller diameter than those of Halictus; in fact, inter- 
mediate in size between the burrows of H. abdominalis and 
H. Morio—too small to have admitted the female of 
H. abdominalis. These proceedings were observed on several 
occasions. No males of any of the bees were to be seen at 
this time, those of Andrena having disappeared some time, 
and those of the Halicti not being developed. On visiting 
the colony one cloudy morning 1 was much delighted to 
observe the head of one of the species of bees at the mouth 
of most of the burrows,—the female Halicti at their own 
burrows, and Sphekodes also at dheir own. The result of my 
observations of this colony led me to believe, still more 
firmly, that Sphekodes is not a parasite. Since the time 
when the above observations were made, I have on several 
occasions detected Sphekodes busily engaged in forming ber 
burrow ; a fact which I consider conclusive of the correctness 
of the opinions above stated.”—‘ Catalogue of Bees, p. 15. 
