, 612 Prof. Westw@@@ on the minute Diptera 
examining which a small worm or larva was found at 
the first joint, which had caused this singular enlarge- 
ment. ‘T'o observe the transformations of these worms, 
I placed several in a glass bottle. The larva is white, 
two lines long, ten-jointed; the head pointed, black at its 
extremity, with a V-like mark. It changed to a chrysalis 
on the 25th May. ‘This chrysalis is yellow, shining, 
rather more than a line long, flat, and rimged. The flies 
began to make their appearance on the 12th June. The 
perfect insect is rather more than a line long. Its head 
is yellow, eyes black; it bears on the vertex a black 
triangle. The black antenne are somewhat nodose, with 
some hairs. The thorax is black above, marked with 
two yellow longitudinal lines, beyond which, near the 
abdomen, is a yellow crescent-like spot (scutellum). 
The under side of the thorax is yellow. The fore legs have 
two black spots. The abdomen is black above, yellow 
beneath, and four-jointed. The balancers are white ; 
the wings are glossed with red and green, and extend a 
little beyond the body. The portion of the legs next the 
body is greyish, with the extremities black. The fly may 
be named Musca pumilionis. We are still ignorant 
whether the eggs are laid on the stems of the rye. On 
the 23rd April the larve were still small, and they 
attained their full size by the 25th May. As there is no 
hole visible at the side of the straw, it would appear that 
the eggs or larve are deposited on the leaves. When 
holes are there found, they are made by the larva of 
Phalena secalis or by some other insect. When the 
fly emerges from the chrysalis-skin it creeps to the top 
of the sheath and makes its escape. The stunted rye 
plants, beginning to assume a yellow colour and dry 
about the 14th July, were so numerous in some fields 
that as many as from eight or twelve to fourteen might 
be counted in a space of four square feet; hence may be 
seen how great is the mischief they produce, which may 
be prevented by cutting up and burning the infested 
plants, and thus destroying the enclosed insects. I have 
thus cut up as many as 350 shoots. 
Fabricius (Syst. Antl., p. 216), simply observes of. 
Musca pumilionis, ‘‘ Habitat in Secalis, Tritici culmis, 
quos omnino destruit’”; but Fallen, in the ‘ Diptera 
Suecica, Oscinides,’ p. 7, gives a more detailed descrip- 
tion and the following explanatory note :— 
