38 
PEELIMIXAEY EEPOKT OX ALFALFA WEEVIL. 
OTHER PARASITES. 
The following three parasites came mainlv in the last two sliipments 
from Italy. The adult of one species (CanidieUa curculionis Thoms.) 
(fig. 25) oviposits in the larvse of the alfalfa weevil in different stages 
of development, but the offspring therefrom 
emerge from the 
cocoon spun by the 
weevil, the cocoons 
of the parasite always 
showing through the 
meshes of the cocoon 
of the weevil (see fig. 
27). This species has 
two generations an- 
nually and hibernat es 
as cocooned larvae. 
The alfalfa stems 
from which the three 
species of parasites 
of this group were 
reared were also in- 
fested by Apion pisi Fab., and therefore some or all of the group may 
perhaps also parasitize this latter insect. Owing to its small size, 
however, as compared to the parasites, this seems rather unlikely. 
The two additional species reared with the preceding 
are not definitely determinable, but 
one is PJiygadeuon sp., and the 
other ma}^ prove to be Mesochorus 
nigripes Ratz. Of this latter spe- 
cies Mr. T. W. Wassiljew, a Russian 
entomologist, under date of Febru- 
arv 6, 1911, wrote us: 
Fig. 21. — Pteromalid parasite of larva 
and pupa of the alfaKa weevil: a, 
Enlarged pupa of alfalfa weevil -with 
eggs of parasite in place; b, egg, 
greatly enlarged. (Original.) 
Fig. 22.— Pteromalid parasite 
of larva and pupa of the 
alfalfa weevil: Larva. 
Greatly enlarged. (Orig- 
inal.) 
I wish to say that I am able to give you 
only one instance of a parasite having been 
found, and that was in the vicinity of Tasch- 
kent (Turkestan), where I noticed in the 
past year [1910] that over 20 per cent of the 
larvae of P. variabilis were attacked by an 
Ichneumon parasite. Unfortunately I do 
not know the name of this species of para- 
site at the present time, other than that it be- 
longs to the Ichneumonidae. Judging from 
the elliptical, thick-shelled cocoon it might 
possibly have been Mesochorus nigripes Ratz., which Mr. Ratzeburg (The Ichneu- 
monidas, III, p. 120) gives as a parasite of P. rumicus. 
All of these parasites resemble each other to a certain degree, and 
figure 25 will suffice to illustrate them, for the present at least. At 
the present stage of this experiment in introducing parasites of the 
Fig. 23.— Larva of ptero- 
malid parasite attack- 
ing pupa of alfalfa 
weevil. Enlarged. 
(Original.) 
Fig. 24.— Pupa of 
pteromalid para- 
site sho^\•n in fig- 
ures 22 and 23. 
Greatly enlarged. 
(Original.) 
