THE NATURAL HISTORY OF THE FUNGUS GNATS 
LEPTOMORPHUS BIFASCIATUS (SAY) 
AND L. SUBCAERULEUS (COQUILLETT) 
(DIPTERA: MYCETOPHILIDAE) 1 
By William G. Eberhard 
Museum of Comparative Zoology, Harvard University 2 
Although there are many species of Mycetophilidae (or Fungi- 
voridae) and some that are quite common, little is known about the 
natural history of most species. The literature on the genus Lepto - 
morphus is typically scanty: there are no descriptions of any activities 
of adults, and only brief descriptions of the general habitat and 
activities of eggs, larvae, and pupae of one species, L. walkeri 
(Edwards 1925, Brocher 1931, Madwar 1937). This report, which 
includes observations on all life stages of Leptomorphus bifasciatus 
and L. subcaeruleus , is the first study of the natural history of 
these species. 
Most of the observations were made during the summer of 1968 
near Rensselaerville, N.Y., at the E. N. Huyck Preserve, and a few 
additional notes were made on individuals found near West Chester- 
field, New Hampshire. Leptomorphus subcaeruleus was found near 
West Chesterfield, and both this species and L. bifasciatus (with 
L. subcaeruleus most common) occurred on the Huyck Preserve. 
I discerned no difference in the habits of the two species, and adult 
males and females of both species were found at the same time at 
several sites in the Huyck Preserve. Specimens of larvae, pupae, and 
adults of both species have been deposited in the Museum of Com- 
parative Zoology in Cambridge, Massachusetts. 
*1 am grateful to the directors and staff of the E. N. Huyck Preserve for 
generously supporting a summer of research, and to Dr. R. Dalgleish for 
help in obtaining financial support for publication of this paper. I am also 
indebted to Dr. R. Gagne for identifying adult specimens, Dr. F. Shaw for 
useful advice, and Dr. M. Gordon for supplying culture media. My wife 
Mary Jane has offered valuable help with all stages of this study. Photo- 
graphic supplies were furnished by Harvard University. 
2 Present address Depto. Biologia, Universidad del Valle, Cali, Colombia. 
Manuscript received by the editor September 25, 1970. 
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