PAN-PACIFIC ENTOMOLOGIST 
Vol. 55, No. 1, pp. 27-33 
NEW SPECIES OF HELICOPSYCHE 
(TRICHOPTERA, HELICOPSYCHIDAE) 1 
D. G. Denning 
2016 Donald Dr., Moraga, CA 94556 
AND 
R. L. Buckle 
Univ. of New Hampshire, Durham, 03824 
Members of the genus are worldwide in distribution with the majority of 
species in the subtropical and tropical regions. Of the approximate 60 
species which have been described, only 4 species are known from North 
America north of Mexico: borealis, mexicana, piroa and limnella. It is 
probable that several northern Mexican species will be taken in portions of 
Arizona, New Mexico and Texas. The well known larvae may be found in 
clear, well aerated streams and congregates of 100 or more prepupae and 
pupae may occasionally be found. In the females the bursa copulatrix pre¬ 
sents specific characters which should be illustrated when associated with 
the male. In the males those species that have no mesal lobe on sternum 6 
are rare; in contrast, the presence of a mesal lobe in described females is 
rare. Future descriptions should record the presence or absence of this 
structure. In this paper five new species are described, one from southern 
California and four from Mexico and Central America. Length is given from 
head to tip of the wings. Deposition of types is indicated under each species. 
Helicopsyche lewalleni, new species 
Resemblance to piroa Ross, vergelana Ross and tapada Denning is ap¬ 
parent in the contour of the clasper and its mesobasal lobe. The species 
belongs to the group in which the females possess a mesal lobe on sternum 
6. Diagnostic characters: claspers with base long, narrow, mesobasal lobe 
slender; phallus long and arcuate. 
Male .—Length 6 mm. Antennal scape slightly longer than next three seg¬ 
ments. Spurs 2-2-4, prominent, setose (in vergelana spurs are 1-2-4). Cerci 
small, ovate. Mesh-like reticulation present on sterna 3, 4; cephalic and 
caudal margins of sternum 6 dark brown, left pleuron with minute ovate 
translucent area along brown pigmented line; mesal lobe (Fig. 1A) lightly 
pigmented, elongate, length exceeds width of segment. Cephalic margins 
terga 5-9 dark brown, mesal excision broad, shallow. Genitalia as in Fig. 
1. Sternum 9 narrow, bifurcated brown lateral apodeme indicates margin of 
