玉米不同组织对亚洲玉米螟幼虫寄主适合度的影响研究

Study on the Effect of Different Tissues of Maize on the Host Fitness of Ostrinia furnacalis( Guenée)

亚洲玉米螟是严重影响玉米产量和品质的重要害虫,能取食危害玉米心叶、茎秆和籽粒等不同组织,为探索玉米不同组织对亚洲玉米螟幼虫寄主适合度的影响,本研究室内测定了亚洲玉米螟幼虫取食玉米心叶、籽粒、茎秆、穗轴和苞叶后其头宽、体长与体重的增长规律,并与取食人工饲料的幼虫头宽、体长与体重增长情况进行了比较.结果表明,取食玉米不同组织后,亚洲玉米螟幼虫的存活、生长和发育动态不同,其中取食穗轴和苞叶的幼虫存活率最低,显著低于其他组织及人工饲料.取食玉米心叶的幼虫发育历期最短,取食穗轴和玉米苞叶的玉米螟幼虫各龄发育历期延长,取食心叶、籽粒、秸秆、穗轴、苞叶、饲料的幼虫发育历期分别为3.10～5.65,3.15 ～4.45,3.18 ～5.40,3.15 ～6.60,3.15 ～7.20,3.21 ～4.89 d.取食玉米心叶的1～5龄幼虫头壳增加指数最大（1.4～2.1）,高于取食籽粒、秸秆、穗轴、苞叶、人工饲料的幼虫头壳增加指数,依次为1.3 ～2.0,1.3 ～1.8,1.2 ～1.7,1.3 ～1.6,1.3 ～2.0.取食玉米不同组织及人工饲料的幼虫体重和体长增加倍数大小顺序为心叶＞籽粒＞秸秆＞人工饲料＞穗轴＞苞叶,且低龄期幼虫体长增加的倍数大于高龄期幼虫,而高龄期幼虫体重增加速度大于低龄期.结果表明,玉米不同组织影响亚洲玉米螟幼虫的生长发育,其中玉米心叶组织最适合亚洲玉米螟幼虫的生长发育,而穗轴和苞叶不适合亚洲玉米螟的生长发育.

Asian corn borer （ ACB）, Ostrinia furnacalis （ Guenée）, is one of the most important in- sect pests in maize, which usually causes serious yield loss and reduces the quality of maize, and also damages the maize whorl leaf, maize kernel, maize stalk, maize cob, maize bract. The fitness of lar- vae of O. furnacalis fed with different maize tissues was studied in laboratory by evaluating survival rate, development duration, increase of the head capsule width, body length and weight of larvae after feeding on the different tissues of maize, and the results were compared with that of larvae fed with the artificial diets. The results showed that the survival rate and development of the larvae of 0. furnacalis were varied with different tissues of maize ; the survival rate of larvae was significantly lower than those fed with maize cob, maize bract and artificial diet. The development duration of the larvae decreased after feeding maize whorl leaf, and increased after feeding maize cob and maize bract. The develop- ment duration of larvae was 3.10 ~ 5.65, 3.15 -4.45, 3.18 -5.40, 3.15 -6.60, 3.15 -7.20 and 3.21 ~4. 89 d after feeding the maize whorl leaf, maize kernel, maize stalk, maize cob, maize bract and artificial diet, respectively. The head capsule width index of the larvae from thel st instar to the fifth instar increased rapidly after feeding the maize whorl leaf, than that of feeding the maize kernel, maize stalk, maize cob, maize bract and artificial diet. Te increase rate of body weight of O. furnacalis after feeding the different tissues of maize and artificial varied with a rank of maize whorl leaf 〉 maize kernel 〉 maize stalk 〉 artificial diet 〉 maize cob 〉 maize bract, the growth rate was higher in the lower instar period than that of in the higher instar period, but the growth rate of the body weight in the high- er instar was much higher than that of in the lower instar. All the results showed that the maize whorl leaf was suitable than that of other maize tissues for the growth and development of the larvae of O. fur- nacalis, however, the maize cob and maize bract were not suitable for the the growth and development of the larvae of O. furnacalis.