桫椤叶蜂对2种寄主植物的选择性与适应性研究

Host Selectivity and Adaptability of Rhoptroceros cyatheae to Alsophila spinulosa and Gymnosphaera metteniana var.subglabra

采用养虫笼产卵法、叶碟法测定了桫椤叶蜂对不同植物的寄主选择性,观察幼虫取食不同嫩叶的生长发育情况,分析桫椤叶蜂与不同寄主植物的关系。结果表明:桫椤叶蜂成虫对小黑桫椤表现出显著的产卵选择性,在桫椤和小黑桫椤上的产卵量分别为(38.25±8.27)粒和(67.38±7.11)粒,2~5龄幼虫也均表现出显著偏好取食小黑桫椤。以2种植物为食的幼虫发育期、羽化率、成虫寿命无显著性差异,而以桫椤为食的比以小黑桫椤为食的老熟幼虫期、蛹期显著延长,幼虫存活率、化蛹率则显著降低。由此表明桫椤叶蜂在寄主植物间具有不同的选择性,成虫的产卵选择性与幼虫的取食选择性一致,与桫椤相比,小黑桫椤对桫椤叶蜂具有较高的适合度。

The host selectivity of Rhoptroceros cyatheae to different plants was determined using cage spawning and leaf plate method.The growth and development of larvae feeding on different tender leaves were observed.The relation between R.cyatheae and different host plants was analyzed.The results showed that R.cyatheae adults showed significant oviposition selectivity to Gymnosphaera metteniana var.subglabra.The number of eggs laid on Alsophila spinulosa and G.metteniana var.subglabra were(38.25 ± 8.27) and(67.38 ± 7.11),respectively.The 2nd to 5th instar larvae also showed a significant preference for feeding on G.metteniana var.subglabra.There is no significant difference in the development stage,adult longevity and emergence rate of larvae feeding on 2 plants.The mature larval stage and pupal stage of R.cyatheae which fed on A.spinulosa were significantly prolonged than that fed on G.metteniana var.subglabra,while the larval survival rate and pupation rate were significantly reduced.It can be seen that R.cyatheae has different selectivity among host plants.The oviposition selectivity of adults is consistent with the feeding selectivity of larvae.Compared with R.cyatheae feeding on A.spinulosa,the R.cyatheae feeding on G.metteniana var.subglabra has a higher fitness.