314 Mr. of Withycombe on the 
The food of Boreus appears to be largely fluid animal 
matter, judging by the stomach contents, but I have never 
seen it attack living insects. The only specimen which 
remained alive for any length of time was a female, which 
was kept going for thirty-seven days on the juices of 
crushed flies. Insects, however small, were not touched 
so long as they showed any signs of life, but a fly, crushed 
so as to force out some of the body contents was accepted 
—the soft parts alone being eaten. I am therefore obliged 
to conclude that the imagines feed on damaged or dead 
insects. Without food the males usually died in just over 
a week, the females in two or three weeks. 
Pairing takes place shortly after emergence, the male 
carrying the female on its back as in the case of the flea. 
The female lays eggs from time to time, but with me 
these have always been laid singly or at most two at a 
time. Little use is apparently made of the long ovipositor 
for boring, as no eggs were found deeper than the bases of 
the moss plants. 
The moss preferred by the insect in Epping Forest 
appears to be Mniwm hornum, but larvae have been found 
in other mosses. 
The egg is 5 mm. long x *3 mm. broad, white and trans- 
lucent when first laid. The surface is smooth except for 
very slight granulations.. Little change in colour is notice- 
able as hatching approaches, which usually occurs on the 
ninth or tenth day with an average temperature of 47° F. 
About half the eggs laid were, however, sterile. ‘Ten was 
the maximum number laid by a single female, but had she 
lived longer more might have been obtained, as examina- 
tion after death showed at least a dozen eggs in the 
oviducts. 
Hatching took place from the end of November to the 
beginning of December, but being rather fully occupied 
and seeing several eggs still unhatched I postponed ex- 
amining the larvae for a week. After this period had 
elapsed they were about 1-5 mm. long and quite similar 
in structure to the full-fed larva. The remaining eggs 
from which I had hoped to obtain larvae for examination 
immediately on hatching, proved to be sterile. I am 
therefore not in a position to confirm Brauer’s observation 
that the newly hatched larva possesses abdominal prolegs. 
On the 27th December (four weeks after hatching) the 
larvae—fed on moss—were 3 mm. long. At this stage 
