Life Histories of Agrion Aequabile and Agrion Maculatum
While the mature nymphs of Agrion aequabile Say and Agrion maculatum Beauv. are readily distinguishable in the field, the species are easily confused in earlier instars, particularly where both occur in the same stream. The distributional ranges of the two forms overlap in the Canadian and Transitio...
| Published in: | Annals of the Entomological Society of America |
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| Main Author: | |
| Format: | Text |
| Language: | English |
| Published: |
Oxford University Press
1939
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| Subjects: | |
| Online Access: | http://aesa.oxfordjournals.org/cgi/content/short/32/3/601 https://doi.org/10.1093/aesa/32.3.601 |
| Summary: | While the mature nymphs of Agrion aequabile Say and Agrion maculatum Beauv. are readily distinguishable in the field, the species are easily confused in earlier instars, particularly where both occur in the same stream. The distributional ranges of the two forms overlap in the Canadian and Transitional faunal zones; thence, aequabile is found northward to the Hudson Bay Slope, maculatum southward to Florida and Texas. In Ontario, as elsewhere over their range, the nymphs are distinctly local in occurrence, being nowhere plentiful, and restricted for the most part to slow creeks and quiet areas of running streams. The distribution of each species in a stream appears to be determined by rate of flow, depth of water, type of vegetation and other factors. |
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