Abstract
We determined the phenology and life-cycle of a population of the perlid stonefly, Agnetina capitata (Pictet), in Cascadilla Creek, Tompkins County, New York, including the pattern of larval growth throughout the year, the period of adult emergence, and the development of eggs under laboratory conditions. Eggs did not develop at 5°C and hatching was negligible at 10°C, suggesting that the lower threshold for embryonic development in A. capitata is above those temperatures. Median egg development time significantly decreased with increasing temperature from 15 to 20-25°C. Independent of temperature, however, there was considerable variation in the development time within egg clutches. Thus, the delay in hatching of A. capitata eggs is complex, showing characteristics of both quiescence and diapause-mediated dormancy. Changes in larval size were not observed during the winter, suggesting that stream temperatures are too low for growth and development. Last instars first appeared in May, and pharate adults w...
Published Version
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