SILVER-STRIPED WEBWORM, CRAMBUS PRAEFECTEL- 
LUS ZINCKEN‘ 
By Ceorgk G. Ainslie 
Entomological Assistant^ Cereal and Forage Insect Investigations^ Bureau of Entomology^ 
United States Department of Agriculture 
INTRODUCTION 
Although of less economic importance than many other members of 
the genus, Crambus prdefectellus is so widely distributed that it is sure 
to be met with by anyone interested in these beautiful little moths. It 
is one of several species with a longitudinal silvery-white stripe in the 
forewing (fig. 2). It is most likely to be confused with C. leachellus 
Zincken, which, however, is a larger species with the white stripe running 
much closer to the costal margin of the wing than it does in praefectellus. 
Crambus quinquareatus Zeller and C. unistriatellus Packard also resemble 
it in size and general pattern, but in the former the apex of the wing is 
acuminate and in the latter the white stripe runs the full length of the 
wing, characters which easily distinguish their possessors from the species 
under consideration. 
SYSTEMATIC HISTORY 
Crambus praefectellus was first described by Zincken (9, p, 24gy in 1821 
from specimens sent him from Georgia. He placed it in the genus Chilo, 
which at that time was synonymous with what we now know as the 
subfamily Crambinae. Clemens (j, p, 20j) redescribed it in i860 as 
Crambus involutellus. In his revision of the group in 1863, Zeller {8, p. j8) 
placed Zincken's species in its present genus and incorrectly placed 
involutellus as a synonym of leachellus Zincken. In this he was followed, 
with some hesitation, by Grote (7, p, 77), but Femald (5, p. 45) corrected 
the error and first placed involutellus Clemens as a synonym of praefectellus 
Zincken, a course approved by all later writers. The synonymy then 
stands as follows: 
Chilo prarfectellus Zincken, 1821 
Crambus involutellus Clemens, i860 
Crambus pra^ectellus (Zincken) Zeller, 1863 
Although the bibliography of this species comprises some 25 titles, the 
great majority of these are merely references to the occurrence of the 
moths in various localities. Felt (4, p, 85) figures and discusses the 
species, but since he did not find it at Ithaca, N. Y., where his work was 
done, he gives us no biological information. Fernald (6, p, 31) figures 
and describes the adult and concludes with the comprehensive state¬ 
ment, “ Early stages and food plant unknown.'* Since that time Britton's 
paper (^, />. 222) is the only publication that adds to our knowledge. 
^ Accepted for publication July xz, 1933. This paper is the fourth in a series of Contributions to a 
Knowledge of the Crambinae of North America. I, Cramlms hemiochrellus Zeller, appeared in Annals 
of the Entomological Society of America for March, 1918, and II, Crambtts laqueatellus Clemens, appeared 
in the June, 1933, issue of the same joumaL The third paper, entitled, ^‘Striped Sod Webworm, Crambus 
mutabilis Clemens,” precedes this paper in the Journal of Agricultural Research. 
* Reference is made by number (italic) to “ Literature cited,” p. 424-435. 
Journal of Agricultural Research, VoL XXIV, No. 5 
Washington, D. C. May 5, 1933 
adp Key No. K-107 
(415) 
