XI. On the Life-history of Boreus hyemalis L. By 
C. L. WirnycomBe. 
Puate. VIII: 
[Read October 5th, 1921.] 
Last December I exhibited before this Society some 
specimens of Boreus hyemalis together with eggs of the 
same. Having now more or less completed my observa- 
tions on the life-history of this insect, I have much pleasure 
in submitting an account thereof. . 
“Kence 
Fria. 2. Boreus hyemalis, 9. 
In Epping Forest Boreus first appears as the perfect 
insect in November and may possibly exist right through 
the winter as such, but personally I cannot claim to have 
taken it later than December. 
As is also the case with other members of the Mecoptera, 
Boreus possesses a long rostrum, at the end of which are 
situated the mandibles, toothed internally and fitted for 
biting. The head also bears two large compound eyes 
but no ocelli. 
In both sexes the wings are reduced, but especially so in 
TRANS. ENT. SOC. LOND. 1921,—PARTS Ill, IV. (JAN. ’22) 
