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XXIII. The Life History, and Occurrence as British, 
of Lomechusa strumosa, F. By H. Sr. J. 
DONISTHORPE, F.Z.S., F.E.S. 
[Read November 6th, 1907. ] 
THE life history of this remarkable beetle, which has been 
worked out by Father Wasmann, is of the greatest interest 
both to the student of insect bionomics as well as the 
scientific entomologist. 
Lomechusa strwmosa is a dweller in the nests of the 
blood-red robber-ant Formica sanguinea (our most inter- 
esting indigenous species of ant both on account of its 
practice of making slaves and its highly intelligent habits), 
of which the beetle is a guest in the truest sense of the 
word, as it is both fed and licked by its hosts. Lomechusa 
possesses short aborted labial palpi, and patches of golden 
hairs on the abdomen whence the ants obtain a sweet 
secretion, of which they are very fond. I may here 
mention that I kept some Lomechusas in small plaster 
nests with glass tops, in which were also ants and other 
insects found in various ants’ nests, including several 
Myrmetes piceus, a small Histerid found with Formica rufa. 
These artful little beetles discovered that Lomechusa pos- 
sessed this secretion, and would frequently climb up the 
legs of the beetle on to its back, where they would remain 
sucking at these patches for some time, often to the evident 
discomfort of the Lomechusa, which appeared somewhat 
agitated. ; 
In studying living specimens of Lomechusa one may con- 
tinually see the ants both feed the beetle and also lick 
it on these patches. If the plates of the abdomen be 
removed and put under a high power, the orifices under 
the hairs, whence the secretion exudes, can be well seen. 
The beetles also ask to be fed, by tapping the ants with 
their antennz. I find, however, that they can also feed 
themselves. I have seen them suck at honey given to the 
ants, and bite at dead ants, and larve given to, or killed 
by, the latter. One beetle sucked for a long time at a 
cut-up Hryzx ater larva, another attacked and sucked a live 
caterpillar. When a lot of ants are feeding at the honey 
TRANS. ENT. SOC. LOND. 1907.—PaRT IV. (FEB.’08) 28 
