BEES AND THEIR ENEMIES. 
115 
facets, seated upon a sort of footstalk. The man¬ 
dibles are lancet-shaped and very acute, and the head, 
hy reason of the protuberant eyes, has very much the 
shape of a dumb-bell. The antennae are branched, but 
in Halictophagus, they are fiabellate. The thorax is 
greatly developed; the superior wing is like a rudi¬ 
mentary wing-case, and is twisted, the inferior wings 
are very large, and fold along the abdomen in repose 
like a fan; the legs are slender, and the tarsi with four 
joints in Stylops , with three in Halictophagus, and with 
two in Elenchus; the abdomen is long, very flexible, 
and consists of eight segments. The insects themselves 
do not exceed a quarter of an inch in length in the 
largest, but they are generally very much smaller. The 
perfect insect is very short-lived, not surviving many 
hours, as just stated. They are usually found in the 
months of May and June, and they have been dis¬ 
covered to infest several species of Andrena and Ha- 
lictus , for instance the A. nigro-cenea, upon which Mr. 
Kirby first found it; A. labialis , which I have frequently 
caught stylopized; A. rufitarsis, fulvicrus, Mouffdella, 
tibialis, Collinsonana, varians, picicornis, nana, parvula, 
ocantliura, conveociuscula, Afzeliella, Gwynana , etc., and 
upon Halictus ceratus, etc. 
The other mode of parasitism destructive to the bees is 
where the parasite deposits its own egg upon the proven¬ 
der stored by the bee for the sustenance of its own young. 
The young of the parasite, either by being more speedily 
hatched or more rapacious than the larva of the sitos, 
starves the latter by consuming its food. This kind of 
parasites consists of several Diptera, but they are mostly 
bees which form a distinctive subsection of the family of 
true bees (Apidat), the subsection being called the Nudi- 
1 2 
