1975] 
Tarter , Watkins , & Little — Nigronia 
87 
Adult Stage. — The first adult fishfly was collected near the 
stream on May 16. In one hour 13, 8 and 3 adults were observed 
on May 20, 22, and 25, respectively. On different occasions, several 
wings of adult fishflies were found scattered along the stream bank. 
Apparently, birds or other predators had fed upon the adults. No 
wings or fishflies were found after May 25. The approximate flying 
season for N. fasciatus was 10 days. 
Oviposition was observed in the field on May 20 and 22. Females 
oviposited their entire egg mass on the underside of leaves 4-6 m 
above the stream between 1300 and 1600 hours. Several leaves with 
egg masses were brought to the laboratory and suspended over water* 
Hatching occurred in 14 days and first-instar larvae (1. 5-2.0 mm, 
body length) fell into the water and crawled underneath rocks. 
There was high correlation (r = 0.95) between the numbers of 
eggs produced and the total length of female fishflies. The following 
equation was calculated to express this relationship. 
Y = —2800.0 + 93.9X 
where Y = the number of eggs, and 
X = total length, mm 
Ovarian egg counts of 10 females showed a range from 275 to 1134 
eggs per female (x = 680). 
Acknowledgements 
We are grateful to the following graduate students for assistance 
in the field: Diana Ashley, Randy Farmer, Jerry Faulkner, David 
Hamilton, Nell Hanson, Fred Kirchner, Michael Midkiff, Sam 
Much, Steve Muth and Douglas Steele. Special thanks to Dr. N. H. 
Anderson, Department of Entomology, Oregon State University, for 
critically reading the manuscript and Judy Tarter for typing the 
manuscript. 
References Cited 
Baker, J. R., and H. H. Neunzig. 
1968. The egg masses, eggs, and first-instar larvae of eastern North 
American Corydalidae. Ann. Entomol. Soc. Am. 61: 1181-1187. 
Banks, N. 
1908. On the classification of the Corydalinae with description of a 
new species. Proc. Entomol. Soc.. Wash. 10: 27-30. 
Cuyler, R. D. 
1965. The larvae of Nigronia fasciatus Walker (Megaloptera : Cory- 
dalidae). Entomol. News 76: 192-195. 
