424 
Journal of Agricultural Research 
Vol. XXIV, No. s 
pupa is 9.0 millimeters long and 2.0 millimeters wide. The caudal process is flattened 
into a broadly triangular plate with sharp margins, its acute tip bent slightly ventrad. 
Close to the tip of this plate below are two slender bristles with upturned ends, while 
above, more widely spaced and standing about halfway from the tip to the basal 
angles of the plate, are two shorter, smaller bristles with down-turned ends. Beneath, 
the process is flattened but not excavated. 
The data as to the duration of the pupa stage are included in Table 
III. It varies somewhat, depending on tihe temperature, in the writer's 
records ranging from 9 to 18 days. The last, however, is very unusual, 
and the average of all the records puts it at 10.65 days, which is much 
more nearly correct. Ten days may be taken as the usual duration of 
this stage during the growing season. 
SYSTEMATIC RELATIONSHIPS 
Crambus praefectellus is closely similar to C. leachellus in structure as 
in wing markings. The male genitalia diflFer in that in the former spe¬ 
cies the cucullus of the harpe is narrower and somewhat more falcate, 
the free costal margin is shorter and more highly chitinized, and the 
comutus of the aedoeagus is smaller. C. unistriatellus also undoubtedly 
belongs to this group. Its harpes and uncus are very similar, but the 
aedoeagus differs somewhat in its armament. Another species, as yet 
not definitely determined but externally very similar to C. leachellus, has 
genitalia which place it in this group, though it is certainly specifically 
distinct from any of the other members. C. quinquareatus (considered 
by Felt as C. hastiferellus Walk.) is placed in this ^oup by Felt (4, 
8 J), but for want of more certain synonymy its position is not discussed. 
SUMMARY 
Crambus praefectellus is an American species widely distributed through¬ 
out the eastern half of the United States. While not often injurious, it 
has shovm itself capable of causing serious damage. 
It breeds continuously throughout the growing season. The genera¬ 
tions are not distinct, but rearing records indicate that three generations 
per year is the usual number. 
The moths are not often abundant. They prefer waste or weedy 
land and are seldom found in clean grasslands. The larvae are readily 
reared on grasses. Winter is passed by the partly grown or mature 
larvae. The moths from the mature larvae emerge early in the spring 
and are the fiirst Crambus moths to appear. 
LITERATURE CITED 
(1) AlNSLiie, George G. 
1922. WEB WORMS INJURIOUS TO CEREAIv AND FORAGE CROPS AND THEiR CON- 
TROi.. U. S. Dept. Agr. Farmers’ Bui. 1258, 16 p. 
(2) Britton, W. E. 
1920. A CONNECTICUT CORNPlEbD INJURED BY CRAMBUS PRAEFECTEbDUS ZINCK. 
In Jour. Econ. Ent., v. 13, p. 222-223. 
(3) Clemens, B. 
i860. CONTRIBUTIONS TO AMERICAN LISPIDOPTEROLOGY, NO. 5. In Proc, 
Acad. Nat. Sci. Phila., v. 12, p. 203-221. 
(4) Felt, E. P. 
1894. certain grass-eating INSECTS. N. Y. (Cornell) Agr. Exp. Sta. Bui. 
64, p. 45-102, pi. 14. 
