THE EUROPEAN WHEAT-FLY. 
589 
minute hairs; those of the male will probably be found to 
have a greater number of joints. 
Towards the end of June, or when the wheat is in blos- 
som, these flies appear in swarms in the wheat-fields during 
the evening, at which time they are very active. The 
females generally lay their eggs before nine o’clock at night, 
thrusting them, by means of a long, retractile tube in the 
end of their bodies, within the chaffy scales of the flowers, 
in clusters of from two to fifteen or more. By day they re- 
main at rest on the stems and leaves of the plants, where 
they are shaded from the heat of the sun. They continue 
to appear and lay their eggs throughout a period of thirty- 
nine days. The eggs are oblong, transparent, and of a pale 
buff color, and hatch in eight or ten days after they are 
laid. The young insects produced from them arc little foot- 
less maggots, tapering towards the head, and blunt at the 
hinder extremity, with the rings of the body somewhat 
wrinkled and bulging at the sides. They are at first per- 
fectly transparent and colorless, but soon take a deep yel- 
low or orange color. They do not travel from one floret to 
another, but move in a wriggling manner, and by sudden 
jerks of the body, when disturbed. As many as forty-seven 
have been counted in a single floret. It is supposed that 
they live at first upon the pollen, and thereby prevent the 
fertilization of the grain. They are soon seen, however, 
to crowd around the lower part of the germ, and there 
appear to subsist on the matter destined to have formed the 
grain. The latter, in consequence of their depredations, 
becomes shrivelled and abortive ; and, in some seasons, a 
considerable part of the crop is thereby rendered worthless. 
The maggots, when fully grown, are nearly one eighth of 
an inch long. Mr. Marsham and Mr. Kirby found some 
of them changed to pup® within the ears of the wheat, and 
from these they obtained the fly early in September. The 
pupa represented by them is rather smaller than the full- 
grown maggot, of a brownish-yellow color, and of an oblong 
