Life History and Population Dynamics of Heteroplectron americanum12
Autor: | Robin L. Vannote, Joanne W. Patterson |
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Rok vydání: | 1979 |
Předmět: | |
Zdroj: | Environmental Entomology. 8:665-669 |
ISSN: | 1938-2936 0046-225X |
DOI: | 10.1093/ee/8.4.665 |
Popis: | The generation time for most individuals of a Heteroplectron americanum population in a Delaware coastal plain stream is one yr. Full-grown male and female larvae attain a mean dry weight of 6.5 and 16.1 mg, respectively, by mid-Apr. Pupation period is ca. 21 days and adults emerge and oviposit from mid-May to mid-June. Gelatinous egg masses were found on submerged branches and logs or attached to tree roots and mosses on the stream bank both above and below the water line. Laboratory studies indicate that fluctuations of water levels after oviposition may cause embryonic mortality due to desiccation and in some years delay the escape of larvae from egg masses isolated on stream banks. First-instar larvae appear in June and most larvae attain the final instar by Dec. A one-yr generation time was confirmed by following the growth of larvae that hatched from egg masses introduced into a stream void of this species. |
Databáze: | OpenAIRE |
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