103 
for one of the midge larvae, as it has much the same size and color — 
white or orange. Its body is not so blunt as that of the maggots, how- 
ever, and tapers anteriorly. Furthermore, the chalcid larva is far more 
active than a midge larva. While the latter wriggles about sluggishly 
and aimlessly, the former wriggles along hurriedly, as if it had some 
end in view. A few times I have seen a chalcid larva attack and feed 
upon a maggot of the midge, it being predaceous instead of parasitic. 
The chalcid becomes a naked pupa within the gall, among any of the 
maggots that may have escaped its attacks. 
The clover leaf-midge needs no discussion from the point of view 
of control. Where the clover is frequently pastured or cut (as on 
lawns) it is hard to find any signs of the leaf-midge. 
Das\ncura (Cecidoinyia) trifolii Low 
"1880. Comstock, J. H.— Rep. [ U. S. ] Comm. Agr., 1879, pp. 
197-199. 
Clover Callipterus 
Callipterus trifolii Monell 
This aphid is common in our clover fields every year, but has not 
been destructive as yet. It is far less numerous than the large green 
aphid, Macrosiphum pisi, and is not wide-spread and gregarious like 
that species, but is scattered, and rather solitary in habit. 
C. trifolii, as found on clover, will be recognized, generally 
speaking, as a small yellowish green or yellow species with six longi- 
tudinal rows of dark tubercles on the abdomen. 
This species has received almost no mention in our literature, 
largely because it has done nothing to attract attention. The material 
which we studied was determined tentatively by me from the original 
description, and positively by the author of the species, to whom speci- 
mens w^ere sent by Mr. J. J. Davis. 
Callipterus trifolii was described from Washington, D. C, by 
Monell, who found it again in Missouri. It is common in Illinois, and 
is reported authentically from Iowa, Kansas, Minnesota, North Da- 
kota, New York, Delaware, and Virginia. 
Descriptions. — The following descriptions, sufificiently detailed for 
the recognition of the species, and supplementary to the original de- 
scription, are adapted from manuscript descriptions made by J. J. 
-Davis, in cooperation with Monell. 
The viviparous females (whether winged or not) are pale yellow- 
ish green. Eyes dark red to brown. Antennae pale greenish basally, 
dusky apically, faintly imbricate, and as long as or a little longer than 
the body. Legs pale, dusky at the joints ; tarsi blackish. Abdomen 
with six longitudinal rows of dusky setiferous tubercles. Style globu- 
lar ; cornicles tubercular ; both a little dusky. 
In the zvingless viviparous female (PI. III.. Fig. 5) the dark ab- 
dominal tubercles bear conspicuous capitate hairs, and the length of 
the female averages 1.6 mm. 
