208 
Psyche 
[Vol. 95 
The fibrous silk probably provides a substrate for the formation 
of the solid inner wall which is the major cocoon component and 
has periodic perforations. Aside from mechanical protection, the 
functions of this wall may include resistance to infection, parasitoid 
oviposition, and desiccation. It is not known if the inner wall of more 
mesic species is also the major cocoon component, but C. comanche 
inhabits an arid environment (southern CA), in which desiccation 
protection can be expected to be vital for the two week metamor- 
phic period. On the other hand, there is need for gas exchange: 
hence, the pores. 
Acknowledgments 
I would like to thank S. Karl for his help with plastic embedding 
and electron microscopy, P. Adams, C. Lambert, and T. Eisner for 
their help with light microscopy, and M. Eisner for her help with 
electron microscopy. This manuscript was improved by the reviews of 
I. Baldwin, S. Smedley, T. Eisner and P. Adams. This work was 
supported by grants from the Department of Biology, California 
State University, Fullerton. 
Summary 
The hindgut epithelium in prepupal C. comanche becomes unus- 
ually villous and may be secreting a substance found in the hindgut 
lumen. This substance is probably used to form the solid inner 
cocoon wall; both the inner cocoon wall and the hindgut substance 
have similar staining properties. Malpighian tubule-produced silk 
precursors stain similarly to the outer, fibrous cocoon silk. Hence, 
cocoons appear to be composed of two different substances secreted 
by different tissues. Cocoon structure is also described. 
Literature Cited 
LaMunyon, C. W., and P. A. Adams. 
1987. Use and effect of an anal defensive secretion in larval Chrysopidae (Neu- 
roptera). Ann. Entomol. Soc. Am. 80(6): 804-808. 
Little, H. F., and R. T. Cunningham. 
1987. Sexual dimorphism and presumed pheromone gland in the rectum of 
Dacus latifrons (Diptera: Tephritidae). Ann. Entomol. Soc. Am. 80(6): 
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