ヨトウガの相変異 : VIII 発育中に食草の種類を変えられた場合の発育速度と体色に対する密度の働き
ON THE PHASE VARIATION OF THE CABBAGE ARMYWORM, MAMESTRA BRASSICAE(L.) : VIII. EFFECT OF LARVAL CROWDING ON THE DEVELOPMENT AND BODY COLOUR OF LARVAE WHEN FOOD IS CHANGED

Sadao HIDATA
1963 Nihon Seitai Gakkaishi  
Synopsis HIRATA , Sadao ( Hirosaki Univ . , Hirosaki ) 0皿 the phase variation of the cabbage ar 皿 y − worm , Mamestra brassicae ( L . ) . VH 【 . Effect of larval c 匸owding on the developme且 t and body colour of larvae when fQod is changed . Jap.工. EcoL l3 ,211 − 216 ( 玉963) . It is well known that the larvae of the cabbage arm アworm , Mamestra brassicae take mass − migrations from their original habitat tQ other food plants when they outbreak It is the main purpose of this experiment to
more » ... periment to ascertain whether there are any noticeable characteristics in the adaptability of larvae which were reared Under soLitary and crowded co 丑 ditions encountering the food change in their developmental stages , 160 正 arvae were reared in solitary and 2401arvae in crowd of 10 individuals per vial under the condition 60ntrolled temperature at 25 ℃ and darkness . Young leaves of ChenoPo ・ dium centror "brum a 且 d Brassica oleracea , natural foods for the larvae, were used for their rearing . For the solitary and crowded larvae eight experime 皿tal cultures were prepared , In each culture the larvae were given Chen ・ ρ ・diesm ・ r Brassi ・副 eaves at di丘ere ・ t larval i且star , a ' s shown in Fig ,1. Mortality of the . solitary larvae depends almost entirely on the food plant given and the mortal 三 ty caused by the food changes became higher as they received it in later developmental stages , Mortality of the crowded larvae , however , was not s stro 皿 91y a 挽 cted by the food plant in early larval stages , and almost aU Gf the 働 al instar 互 arvae survived on Chenopodium leaves after they had been reared on Brassica leaves in their preceding instars. Developmental velQcity of the solitary larvae are affected by the kind of food plant at any time of their developme 且 t. 0 皿 the co ロ 亡 rary , the developmental velocity of the crowded larvae was 皿 ot so strongl ア affected il younger stages and also 重 n the 丘nal instar ・when they were reared on Chenopodium after feeding on Brassica in the preceding hlstars・ 工 n th孟 s case it was also a notable result that the larval durat { on was shorter in the crowded cultures tha且 in the so1itary ones . The hody colour of the 丘nal instar larvae was affected by the larval density and also by the food plant . The tendency of darke 且 ing colour in the crowded culture was slightly intensified by changing the food , even if the alternation of food was done just before the 最nal instar.
doi:10.18960/seitai.13.6_211 fatcat:27egur33inf5rfrce57ztl6use