STREPSIPTERA. 303 
closely in front to the posterior part of the head, but easily distin- 
guished therefrom ; the posterior angles of the remaining segments 
are terminated by several setae. The legs are six in number, attached 
to the lateral under surface of the three anterior segments. These 
creatures creep but slowly about the head of the larva (fig. 93. 18.), 
and amongst the hairs of the bee’s tail, and whilst in motion they 
have a very peculiar mode of progression. 
These little creatures, which exhibit many points of resemblance 
with the supposed larvee of Meloe (Pediculus melitte H.), give rise 
to various queries connected with their economy, which it is difficult 
to answer, even by analogy. That every Stylops larva should be thus 
infested to this extent, is in itself singular; but when we inquire, 
when were these parasites deposited in the body of the internal-feed- 
ing parasite Stylops larva? upon what will they now subsist ? or in 
what situation will they remain until they are again enabled to place 
the germs of their progeny in a similar situation in the body of the 
larva of the Stylops? we are compelled to admit our inability to offer 
any satisfactory reply. Is it possible that they may be the larve of 
the Stylops in an active form? Such an opinion is opposed by the 
many apparent anomalies which would attend such a circumstance ; 
but the Strepsiptera are sufficiently anomalous to warrant the proposal 
of such a question. Coccus, Psyche, Oiketicus, Hippobosca, and 
Aphis, may all be cited as possessing anomalous habits and modes of 
development which would exhibit analogies with Stylops, supposing 
the female Stylops to retain its larva form, and to produce such living 
young. The impregnation of such a female might easily be effected, 
although remaining in its fixed position, or the young might be pro- 
duced for several generations without such an act. I have made some 
farther observations upon these minute parasites in the Trans. Ento- 
mol. Soc. vol. ii. p. 186. 
Mr. Pickering has given the following list of species of Andrenz 
which he has observed to be infested with Stylops : — Andrena nigro- 
znea, A. tibialis, A. rufitarsis, A. labialis, A. fulvicrus, A. Collinsonana ? 
A. Mouffetella, A. varians, A. picicornis, A. parvula, A. Xanthura, A. 
convexiuscula, A. Afzeliella, and several new species ; to which he has 
added, from my collection, A. Gwynnana. Recent observations have 
also proved that the allied genus Halictus is also subject to the attacks 
of species of this order. (St. Fargeau, in Encycl. Méth. tom. x. p. 292.) 
Indeed, Mr. Dale has named one of the genera Halictophagus, on 
