Bittacus chlorostigma  McLachlan, 1881

Diagnosis:  This is a large species of hanging-fly with a distinctive yellow or white pterostigma on both wings.  The male epiandrial lobes are large and truncated at the apex.  The male cerci are small, only about half as long as the basistyles.


Distribution – Geographical:  This species is found along the western foothills of the Sierra Nevada of California from Butte County in the north to Tulare and Kern Counties in the south (Penny, 2006).  There is one isolated record from Sand Creek, Klamath Co., Oregon (Byers, 1973b)


Distribution – Temporal:  This species emerges as adults from late March to late June.


Ecology:  This species inhabits the oak/pine woodlands along the lower slopes of the Sierra Nevada.  The habitat is often grassy, open, and relatively dry, often with relatively thick underbrush that includes blackberries and other low shrubs.  At times this species can be quite abundant, with dozens of individuals dispersing at once.


Biology:  The adult female will drop eggs indiscriminately in the environment.  The egg has a ruguose pink covering that protects the egg from desiccation.  The egg undergoes several months of aestivation until the late fall rains begin.  At that time, the egg breaks open the hard pink coating and expands to twice its original size before hatching.  Larval growth takes place during the winter months in the mild foothill climate.


Notes:  The name chlorostigma refers to the coloration of the yellow stigma of most individuals.




Byers, G.W. 1973b. Descriptions and distributional records of American Mecoptera. III. Journal of the KansasEntomological Society, 46:362-375.


McLachlan, R. 1881. On two new Panorpidae from western North America. Entomologist's monthly Magazine  18:36-38.


Penny, N.D.  2006.  A Review of our knowledge of California Mecoptera.  Proceedings of the California Academy of Sciences  Ser. 4, 57(9):365-372.



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