Diapause termination in the millet stem borer, Coniesta ignefusalis (Lepidoptera: pyralidae) in Ghana as affected by photoperiod and moisture.
Studies were conducted in northern Ghana in 1997 and 1998 on the effects of contact moisture and photoperiod on the termination of larval diapause in the stem borer, Coniesta ignefusalis (Hampson). Results obtained over the two years consistently showed that on its own, photoperiod had no significant effect on diapause termination. In combination with contact moisture, however, a long day photoperiod of 13L:11D accelerated diapause termination and increased the cumulative percentage pupation. Contact with moisture was crucial for diapause termination but its influence was more pronounced in larvae collected from the field after March. Generally, access to moisture earlier than April resulted in very high larval mortality. These observations, together with the fact that some of the larvae (12%) denied access to water throughout the experimental period subsequently pupated, suggest that moisture may not be the sole factor triggering diapause termination in C. ignefusalis. The implications of these findings are discussed.
Tanzubil
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School of Animal and Microbial Sciences, University of Reading, Reading, RG6 6AJ, UK. m.bohssini@cgiar.org
McCaffery
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Mensah
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D000818:Animals; D005869:Ghana; D006813:Humidity; D009036:Moths / Q000254:growth & development / Q000502:physiology*; D017440:Photoperiod