THE ENTOMOLOGIST. 99 



"The bees which are included in this genus have hitherto 

 been regarded as parasitic on those comprised in the genus 

 HaHctus; and, indeed, many circumstances tend to support 

 such a supposition. They are usually found burrowing, not 

 only in similar situations, but forming n)ixed colonies. The 

 females of both genera a))pear 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 tlie 

 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 Andrenidce 

 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 18491 discovered a mixed colony of Halictus abdo- 

 minalis, Andrena nigro-aenea, Halictus Morio, Sphekodes 

 subquadratus, and S. 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 1 made close observation on the proceedings of 

 the bees; yet, notwithstanding, 1 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 ilieir 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 her 

 burrow ; a fact which I consider conclusive of the correctness 

 of the opinions above slated." — ' Caialocjue of Bees,' p. 15. 



