同域分布的4种竹笋夜蛾产卵选择行为

Oviposition selection behavior of four sympatric shoot-boring noctuids

竹笋夜蛾是中国南方地区最为重要的笋期害虫。为探究同域分布、寄主相同的4种竹笋夜蛾生态位的分化机制,于室内研究了4种竹笋夜蛾对3种不同寄主植物水竹(Phyllostachys heteroclada Oliver)、鹅观草(Roegneria kamoji Ohwi)和青绿苔草(Carex breviculmis R.Br.)的产卵选择行为。结果表明:4种竹笋夜蛾在3种寄主植物间的产卵选择性差异显著(P<0.01),其中笋秀夜蛾和竹笋禾夜蛾只选择鹅观草进行产卵;4种竹笋夜蛾在各寄主植物产卵位置上具有选择性,偏好在鹅观草叶片、叶鞘上及草根处产卵;4种竹笋夜蛾在产卵总量上差异显著(P<0.01),其中笋秀夜蛾和竹笋禾夜蛾产卵总量最大;4种竹笋夜蛾产卵时间先后依次为基夜蛾>萨夜蛾>笋秀夜蛾>竹笋禾夜蛾,基夜蛾最早羽化产卵,产卵历期10 d,后三者产卵历期重叠。该结果说明,4种夜蛾采用时间隔离和空间隔离2种机制,从行为上避免激烈的种间竞争,保证自身后代的顺利繁衍。

To explore the sympatric speciation of four dominant shoot-boring noctuids, Sapporia repetita, Oligia vulgaris, Apamea apameoides and Kumasia kumaso, the oviposition behaviors of the four hoot-boring noctuids were observed in lab conditions using Phyllostachys heteroclada, Roegneria kamoji and Carex breviculmis as host plants. The results showed that the host preference in oviposition was significantly different among the four hoot-boring noctuids （P 〈 0.01 ）. A. apameoides and O. vulgaris only choose R. kamoji to lay eggs. All four noctuids selected their oviposition sites on different parts of the same plant, with most sites on the leaf surface, sheath and root of R. kamoji. A. apameoides and O. vulgaris spawned more eggs than the other two noctu- ids. Meanwhile, the oviposition time of the four noctuids was different. Kumasia kumaso was the oviposition-earliest moth and its spawning process lasted for 10 days. The oviposition time for the other three species was in sequence of S. repetita 〉 0. vulgaris 〉 A. apameoides. The results indi- cated that the four shoot-boring noctuids used temporal and spatial isolation mechanisms to avoid fierce interspecific competition for the development of their offsprings.