サツマイモの主要食葉性害虫3種の摂食量  [in Japanese] Food Consumption of Three Major Sweet Potato Defoliators, Aedia leucomelas LINNE, Agrius convolvuli LINNE and Brachmia triannulella (HERRICH-SCHAFFER)  [in Japanese]

サツマイモの主要な食葉性害虫であるナカジロシタバ,エビガラスズメ,イモキバガの摂食量を摂食されたサツマイモ葉身部の乾物重で測定し,摂食葉面積を推定した。実験は20, 25, 30°C, 16時間日長区と25°C 8時間日長区を設定し,25°C 16時間日長区のみ各齢期ごとの摂食量を,他の区は最終齢期の摂食量を測定した。ナカジロシタバ幼虫(6齢経過虫)の1頭当り平均摂食量は25°C下で約654mg,葉面積では約170cm2と推定され,最終齢期で総摂食量の約83%を摂食した。摂食量は日長には影響をうけなかったが,20°C下で摂食量が多くなる傾向がみられた。エビガラスズメ幼虫(5齢経過虫)の1頭当り平均摂食量は25°C下で約5g,葉面積では約1,300cm2と推定され,最終齢期で総摂食量の約88%を摂食した。摂食におよぼす日長の影響はみられなかったが,30°Cの高温下では摂食量が多かった。イモキバガ幼虫(4齢経過虫)の1頭当り平均摂食量は25°C長日条件下で約28mg,葉面積では約7cm2と推定され,最終齢期で総摂食量の約61%を摂食した。摂食量は温度や日長によって影響をうけなかった。

Consumption of sweet potato leaves by larvae of three major defoliators, Aedia leucomelas LINNE, Agrius conrolvuli LINNE and Brachmia triannulella (HERRICH-SCHAFFER) was evaluated by the measurement of the dry weight of leaves consumed and the leaf area consumed was calculated. The examination was conducted in rearing larvae of three insects at the constant temperatures of 20,25 and 30℃ under a 16 hr day-length regime. Amount of consumption by larvae in each instar was measured under a 25℃ and 16 hr day-length regime, while under other conditions, the determination was performed only in larvae in the final instar. The mean values of dry weight of leaves consumed by A.leucomelas, A.convolvuli and B.triannulella were approximately 654 mg, or 170 cm^2 in terms of leaf area, 5 g, 1,3000 cm^2 and 28 mg, 7 cm^2,respectively, and 83%, 88% and 61% of the total amounts were consumed by the larvae in the final instar in the respective species. The food consumption of A.leucomelas was the highest at 20℃, but that of A.convolvuli was highest at 30℃, though the effects of day-length on food consumption were not recognized in both species.