草地贪夜蛾和亚洲玉米螟种内及种间的竞争行为

草地贪夜蛾Spodoptera frugiperda (J.E.Smith)和亚洲玉米螟(以下简称“玉米螟”)Ostrinia furnacalis (Guenée)是玉米上的重要害虫, 二者在玉米田常混合发生, 存在对食物和空间资源的竞争关系。为探明草地贪夜蛾和玉米螟种内和种间竞争的行为表现, 本文在食物缺乏条件下, 研究了草地贪夜蛾和玉米螟种内和种间的攻击和防御行为。结果表明:草地贪夜蛾种内攻防行为中头部接触是最主要的行为表现, 其中6龄与6龄以及6龄与5龄幼虫竞争时头部接触行为出现次数最多, 在20 min内分别为(17.8±1.7)次和(15.3±1.1)次。玉米螟种内攻防行为中畏缩行为是最主要的行为表现, 在5龄与5龄幼虫的竞争中出现频率最高, 为(14.8±0.7)次。〖JP3〗草地贪夜蛾和玉米螟种间竞争行为中, 二者都主要表现为头部接触行为, 但草地贪夜蛾攻击行为表现更明显。此外, 从存活率上看, 同一龄期的玉米螟和草地贪夜蛾种间竞争中, 草地贪夜蛾具有明显优势; 不同龄期的玉米螟与草地贪夜蛾种间竞争中, 同一组合中龄期相对较高的幼虫具有明显竞争优势。研究结果可为明确草地贪夜蛾和玉米螟的种群优势及制定相应的防治策略提供参考。

Intraspecific and interspecific competition behavior in Spodoptera frugiperda and Ostrinia furnacalis

The fall armyworm, Spodoptera frugiperda (J.E.Smith), and the Asian corn borer, Ostrinia furnacalis (Guenée), are main pests of maize, and often occurred together in maize fields, resulting in some interspecific and intraspecific competition on food sources and space. In order to understand the intraspecific and interspecific larval interaction between S.frugiperda and O.furnacalis, the offensive and defensive movements between these two pests were observed under food deficiency conditions. The results showed that head touching was the predominant movement in S.frugiperda under all the interactive scenarios, with a head touching mean frequence of (17.8±1.7) and (15.3±1.1) times within 20 minutes under the scenarios of 6th vs. 6th instars and 6th vs. 5th instars, respectively. The most frequent movement in O.furnacalis under all the interactive scenarios was recoiling, with a highest mean frequence of (14.8±0.7) times for 5th vs. 5th instars. Under the interactive scenario between S. frugiperda and O.furnacalis, touching was the most frequent movement in both pests, but S.frugiperda showed a higher attack movement than O.furnacalis. In addition, under the interactive scenario of the same instars of S.frugiperda and O.furnacalis, S.frugiperda dominated the interaction, while in the competition between different instars of these two pests, the older ones dominated. This study helps clarify the population advantages of these two pests and formulate corresponding control strategies.