852 
ANNUAL REPORT OF NEW YORK 
YELLOW-BELLIED JANUS. DESCRIPTION OF THE FLY'. 
inserting an egg in the stalk or straw, just below the ear. From 
this egg hatches a tapering, white footless worm, which feeds 
upon the soft pithy substance that lines the cavity in the centre 
of the straw, perforating the partitions at the joints as it works 
its way downward to the root, which it reaches about harvest 
time, and there incloses itself in a thin transparent case, in 
which it remains through the winter. Burning the rye stubble 
after harvest is regarded as the best measure for destroying this 
insect. Other saw-flies of the genus Cep/ius are found in Europe, 
in company with this, and are supposed to have the same habits. 
In our American rye fields we some years see particular heads 
of the grain affected in the same way as above stated. But 
during the tYvo past summers 1 have been unable to find any 
such in my own vicinity, and hence have not had an opportunity 
to ascertain the kind of worm that in our country occasions this 
disease. It may be some of those species of Chlorops which were 
noticed in my second report as producing a similarly prematurely 
ripened appearance in wheat; or it may prove, in some instances 
at least, to be some saw-lly of -this country nearly related to 
the Cephus pygmeeus. A New York insect of this kind, the 
same in size with the European species, and coming abroad 
like it the last of May, has the hind body cylindrical instead 
of being compressed, and consequently' pertains to the genus 
Janus. It is a pretty little fly of a shining black color, with 
the hind body lemon yrnllow except at its base, its mouth 
being straw-colored, and also the hind margin of its collar, 
the base of its wings, a small spot above their sockets, and the 
fore and hind margins of the metathorax. The hind body is 
narrower than the fore body' and more narrow and long than in 
the typical species of this genus, forming almost two-thirds ol 
the total length of the insect, its basal segment is black, edged 
anteriorly with straw yellow, and Yvitli a slender line of this 
color along its middle, ending in a large triangular spot. The 
second sogment is also black except at its hind end; and on the 
sides is a blackish cloud on the sutures of each of the remaining 
segments. The wings are hyaline and glassy, their stigma sooty 
brown, which color extends inward, occupying most of the ante¬ 
rior marginal cell. A faint smoky cloud may also be perceived 
near the middle of the posterior apical cell, and another along 
the margin of the anterior one. The hind feet are dusky. 
