90 Second Report on Economic Zoology . 
others in the base of the buds survive. The male is apterous, very 
minute, blind, and yellow in colour ; they were found by Buckton 
under a scale when examining the contents of a number of galls. Thus 
in this species we get a sexual generation, which 
does not as far as we know occur in laricis. 
The sexually produced egg is always laid 
on the spruce, which is the primary food plant 
of the Aphis, which must now apparently stand 
as Chermes abietis-laricis. How far these two 
races can live upon one tree only is a matter 
at present unsettled. 
Fig. 20. — Wings of a $ 
OF SUMMER GENERATION 
Dreyfus gives the following life-cycle : — 
First Year. 
Generation I. passes winter on spruce as C. abietis and there 
lays eggs. 
Generation II. develops in spruce galls and forms winged abietis 
in August. Part of these migrate to the larch and become 
laricis and lay their eggs on the needles. 
Generation III. hatches on the larch and passes the winter 
under bark scales and in crevices. 
Second Year. 
Generation IV. These come from the eggs laid on the larch, 
the product of III., which acquire wings at the end of May 
and mostly return to the spruce, and their eggs produce 
generation V. 
Generation V. consists of males and females. From the 
sexually produced eggs there then hatch and develop the 
mother queens, which live throughout the winter and corre- 
spond to Generation 1. 
Whether or not each race can live entirely on either the spruce 
or the larch or whether a migration is necessary does not seem to be 
as yet settled. I am confident that the abietis can go on year after 
year on the spruce. One under observation became infected with the 
Chermes in 1895, and since then the Chermes have steadily increased 
year by year. The nearest larch tree is more than half a mile away 
in a straight line. This larch is annually covered with laricis. 
That the spruce in question was quite free a few years ago I know, 
and the first signs of Aphides I saw upon it were winged forms that 
I could not separate from the winged larch species. 
