Effects of photoperiod and low temperature on diapause termination in the yellow-spotted longicorn beetle (Psacothea hilaris) |
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Authors: | yOSHINORI SHINTANI yUKIO ISHIKAWA |
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Affiliation: | Graduate School of Agricultural and Life Sciences, University of Tokyo, Japan |
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Abstract: | Abstract. .The effects of photoperiod and low temperature on diapause termination in the yellow-spotted longicorn beetle, Psacothea hilaris (Pascoe) (Coleoptera: Cerambycidae), were examined using a population from Ino, Japan. Diapausing insects obtained by rearing larvae under short daylength (12 or 13 h) at 25oC were subjected to various treatments. When the photoperiod was changed at the same temperature, diapausing larvae showed a long-day response with a critical daylength between 13.5 and 14h. The diapause was terminated and consequently pupation occurred if the daylength was longer than 13.5 h. Chilling the diapausing larvae at 10oC for 30 or more days also terminated diapause in most larvae irrespective of the photoperiods during and after chilling treatment. In contrast, the post-chilling photoperiod had a critical effect on development of diapausing larvae chilled for only 15 days. |
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Keywords: | Diapause terminationy diapause development photoperiodic response Psacothea hilaris critical daylength |
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