Robertson H G
Department of Zoology and Entomology, Rhodes University, 6140, Grahamstown, South Africa.
Oecologia. 1987 Oct;73(4):601-608. doi: 10.1007/BF00379423.
Oviposition by Cactoblastis cactorum on Opuntia ficus-indica and O. aurantiaca was assessed from the positioning of egg sticks on plants in the field. The number of egg sticks laid on O. ficus-indica plants was affected by: (1) plant size; (2) moth emergence near the plant; (3) cladode condition; and (4) plant conspicuousness. These factors contributed towards the clumping of egg sticks on plants. There was no apparent oviposition preference for one of the two host plant species despite the fact that egg predation was higher and fecundity lower on O. aurantiaca. The selection of a site for oviposition on the host plants was influenced by: (1) cladode condition; (2) height above ground; and (3) shelter from wind during oviposition. Succulent cladodes were the favoured sites for oviposition. The evidence suggests that in C. cactorum, oviposition site selection is largely the net result of a compromise between oviposition behaviour selected for increasing the probability of juvenile survival and oviposition behaviour selected for increasing the probability of laying the full complement of eggs. In addition, environmental and physiological factors such as wind and wing-loading, are thought to place constraints on the range of sites available for oviposition.
通过野外观察仙人掌上卵棒的位置，评估了仙人掌螟（Cactoblastis cactorum）在印度仙人掌（Opuntia ficus-indica）和橙色仙人掌（O. aurantiaca）上的产卵情况。在印度仙人掌植株上产下的卵棒数量受以下因素影响：（1）植株大小；（2）植株附近羽化的蛾子数量；（3）茎片状况；（4）植株的显眼程度。这些因素导致卵棒在植株上聚集。尽管橙色仙人掌上的卵被捕食率更高且繁殖力更低，但对于这两种寄主植物，并没有明显的产卵偏好。在寄主植物上选择产卵地点受以下因素影响：（1）茎片状况；（2）离地高度；（3）产卵时的防风情况。多汁的茎片是首选的产卵地点。有证据表明，对于仙人掌螟来说，产卵地点的选择很大程度上是在为提高幼虫存活率而选择的产卵行为和为提高产下全部卵量的概率而选择的产卵行为之间折中的结果。此外，风和翅载荷等环境和生理因素被认为会限制可供产卵的地点范围。
