ヒメエグリバの発育に及ぼす温度と日長の影響  [in Japanese] Effects of Temperature and Photoperiodism on Development of a Fruit-Sucking Moth, Oraesia emarginata FABRICIUS (Lepidoptera, Noctuidae)  [in Japanese]

ヒメエグリバを卵期から成虫期(産卵開始時)まで, 長日条件下の16, 19, 22, 25, および28℃恒温で飼育し, 各発育段階ごとの所要経過日数を記録した.その結果, 発育速度はいずれの発育段階でも, 高温になるほど速やかであった.19℃以下の低温下では発育の遅延がみられるばかりでなく, 発育速度の個体変動が大きくなり, また幼虫期の死亡率も高かった.計算された発育零点は12∿13℃とやや高く, 全発育を完了するに必要な有効積算温度は556日度であった.短日条件下で飼育すると, 21および25℃いずれの恒温下でも, 幼虫期後半にいちじるしい発育の遅延がみられた.この遅延は発育速度の低下と経過齢数の増加の結果であり, 休眠状態に入ったためとみなされる.休眠誘導の臨界日長は13∿13.5時間であった.

Oraesia emarginata was reared from egg to adult stage at constant temperatures of 16, 19, 22, 25, or 28℃ under long photoperiod (15L-9D). Developmental velocities for respective stages, as well as velocity for the whole stage up to initiation of egg deposition increased as rearing temperatures increased. At temperatures below 19℃, remarkable individual fluctuations in growth velocity and high mortalities in larval stages, in addition to developmental retardation, were recorded. Effective accumulated temperature required from egg stage to initiation of egg deposition in resultant adult moths was determined as 556 day・℃, and developmental zero 12-13℃. Under short photoperiod, a clear slowdown of developmental velocity occurred during the later half of larval development even under favorable temperatures (21 or 25℃). This phenomenon may be interpreted to mean a type of diapause. The critical daylength inducing diapause in the later half of larval development was estimated to be 13-13.5 hr.