Effects of photoperiod and temperature on head-capsule size in Planotortrix octo (Lepidoptera: Tortricidae) |
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| Authors: | Michael C. Morris |
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| Affiliation: | 1. Department of Zoology , University of Auckland , Private bag, Auckland , New Zealand;2. National Institute of Sericultural and Entomological Science, 1-2 , Owashi, Tsukuba, Ibaraki 305, Japan |
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| Abstract: | Abstract The head-capsule widths of Planotortrix octo were measured atphotophases of 0, 2, 6, 12, 14, 16, 18, and 24 h under a LD 24 h cycle. The headcapsule widths of the 2nd, 4th, and 5th instar showed a photoperiodic response, being smaller under photophru;es of 12-16 h. The critical 5th instar head-capsule size above which pupation occurred, appeared smaller at these photophases. However, the critical size could not be determined accurately—or this difference verified statistically—as there wru; some overlap in capsule size between 5 and 6 instar groups. |
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| Keywords: | Photoperiod larval development Planotortrix octo |
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