豚草和苍耳上广聚萤叶甲的寄主选择和取食量比较

Host choice and leaf consumption of Ophraella communa(Coleoptera: Chrysomelidae) on Ambrosia artemisiifolia and Xanthium sibiricum

为探究豚草与苍耳上的广聚萤叶甲种群是否存在分化,对来自这两种植物上的叶甲(分别称为"豚草叶甲"和"苍耳叶甲")进行了选择性试验,并测定了其对5种近缘植物的取食量。选择性试验结果表明,两群来源不同的叶甲对豚草和苍耳的选择偏好存在显著差异,表现为豚草叶甲更偏好豚草,而苍耳叶甲相对更偏好苍耳。对广聚萤叶甲成虫取食量的测定结果表明,对不同测试植物的取食量随来源寄主植物不同而存在显著差异,两群叶甲对向日葵的取食量存在显著差异,但对其他植物的取食量均无显著差异。豚草叶甲对豚草的取食量显著大于对其他测试植物的取食,24 h平均取食量达51.27 mm2,而对其他4种植物的取食量无显著差异,均低于40 mm2;苍耳叶甲取食豚草的量为52.24 mm2(24 h),与取食向日葵和三裂叶豚草量无显著差异,但显著大于取食苍耳和菊芋的量,取食后两种植物的量没有显著差异。研究结果说明,苍耳属植物可能是广聚萤叶甲除豚草外的另一潜在寄主植物。

To study whether Ophraella communa has host specialization on Ambrosia artemisiifolia and Xanthium sibiricum,a dual-choice trial was conducted to study the host selection of the O.communa originated from A.artemisiifolia（ragweed cohort） and X.sibiricum（cocklebur cohort）,with the leaf consumption of the two cohorts on five relative plants X.sibiricum,A.trifida,Helianthus annuus,H.tuberosus,and A.artemisiifolia measured.The ragweed cohort O.communa showed a significant preference for A.artemisiifolia over X.sibiricum,while the cocklebur cohort O.communa showed a significant preference to X.sibiricum over A.artemisiifolia,as manifested by the relative over-preferences.The leaf consumption by the two cohorts differed significantly on sunflower,but had no significant differences on the other test plants.Ragweed cohort showed a significant preference to A.artemisiifolia over the other test plants,with a consumption of leaf discs by 51.27 mm2 in 24 hours,but showed less difference in the preference to other test plants,with the consumption of leaf discs by 〈40 mm^2. The leaf discs consumption of A.artemisiifolia by cocklebur cohort was 52.24 mm^2,not different from the consumption of sunflower and A.trifida but greater than that of X.sibiricum and H.tuberosus,and no significant difference between the latter two plants.It was suggested that X.sibiricum could be a suboptimal host plant as an alternative to optimal A.artemisiifolia for the leaf beetle O.communa.