Development and Survival of Chironomus tepperi Skuse (Diptera: Chironomidae) at a Range of Constant Temperatures |
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Authors: | M.M. Stevens |
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Affiliation: | 1. Department of Freshwater Ecology , University of Vienna , Austria johann.waringer@univie.ac.at;3. Institute of Hydrobiology and Aquatic Ecology Management, University of Natural Resources and Applied Life Sciences , Vienna, Austria;4. Zurich, Switzerland |
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Abstract: | Chironomus tepperi Skuse were reared individually at a range of constant temperatures from 12.5 to 37.5°C (2.5°C intervals), with development and survival monitored at regular intervals. C. tepperi is protandrous, with males developing significantly faster than females at the majority of temperatures examined, due primarily to a shorter final instar. Some individuals completed development at all temperatures, however emergent adults failed to successfully inflate their appendages at 37.5°C. Developmental rate increased with increasing temperature up to 32.5°C, but fell at 35°C. Low adult emergence at 37.5°C precluded a reliable estimate of total development time at that temperature. Survival to adult emergence varied from 10 to 60%, with highest mortality in the pupal stage at all temperatures. Degree-days (DD) and developmental zero (DZ) estimates for egg to adult development are 150.5 DD and 10.5°C for males and 167.1 DD and 10.3°C for females. DD and DZ estimates are presented for each developmental stage. The significance of wide thermal tolerances in a colonist midge species is discussed. |
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