MEGASTIGMUS SPERMOTROPHUS, WACHTL. 55 
the strongly compressed abdomen is brownish-red above, with a 
black longitudinal patch at its base, gradually narrowing behind 
and becoming paler at the edges. Sculpture, hairing, etc., as in 
the female. The body-length of the male measures from 2°75 
mm. to 3 mm.” (= to 3 of an inch). 
So far as I know, the larva has not till now been described. It 
is whitish in colour, and legless. The segments are well marked, 
and, indeed, the general appearance, including the wrinkled and 
curled form, is strongly reminiscent of a weevil grub. The 
marked horny head of the weevil grub, however, is absent. 
Instead, in the Megastigmus larva, each of the two chitinised 
gnawing jaws is somewhat sickle-shaped, the two jaws together 
reminding one of a pair of calipers. The apex of each jaw is 
pointed, and on the concave side is provided with marked teeth. 
These gnawing mouth-parts are red or yellow-brown in colour. 
Those shown in Figure e were drawn under a magnification of 
about 750. 
Lire-HISTORY. 
The flight time of Megastigmus spermotrophus, under normal 
conditions, is, in Scotland, from May onwards. The females that 
have issued proceed to their egg-laying in the young Douglas fir 
cones. ‘The insects may be seen at this time on the Douglas fir 
trees, as also on the top of the seed-beds, some time after sow- 
ing, these last having most likely issued from seed which had 
been sown. ; 
Each infested seed of the Douglas contains only one larva, 
which nourishes itself on the reserve contained in the seed. The 
seed bears no external mark of the internal presence of the 
Megastigmus \arva. Pupation takes place in the seed, there 
being no cocoon. In a number of the seeds which I dissected, 
and from which Megastigmus adults had issued, the contents of 
the seed had been devoured, and only the outer brown testa or 
seed-coat remained surrounding the inner white-coloured peri- 
sperm sheath. In other seeds, on dissection, I found the larva, 
and, where it was full-grown and the seed contents destroyed, 
the white-coloured perisperm-sheath surrounding the larva bore 
a close resemblance to a cocoon. 
Starting from the first laid eggs of the spring brood of Mega- 
stigmus, the generation, probably, can be reckoned as an annual 
one. From Douglas fir seeds received in May, I bred out males 
