Host Leaf Selection by Leaf Miners: Interactions among Three Trophic Levels
Host Leaf Selection by Leaf Miners: Interactions among Three Trophic Levels
复制标题
潜叶虫对寄主叶的选择：三个营养级之间的相互作用
作者：
S. Faeth
在采叶物种 Stilbosis juvantis 中研究了叶片特征对内食性昆虫宿主叶片选择和存活的影响。对开采和未开采的叶子（脱落后）的干质量测量表明，潜叶虫不会根据叶子的大小选择叶子进行产卵和随后的幼虫取食，这可能是因为幼叶潜叶蝇的密度通常较低，并且潜叶虫仅消耗叶子的一小部分。然而，对 18 棵寄主树（其中 6 棵受损叶子的比例已通过实验增加）的普查表明，这些潜叶蛾确实选择了比受损叶子多得多的完整叶子来产卵。由于寄生性增加，受损叶子上的 S. juvantis 的存活率明显低于完整叶子上的矿工。寄生蜂的较高攻击率可能归因于受损叶片的物理或化学变化。因此，以前的食草动物对叶子的损害改变了矿工对叶子的选择。这些结果表明，在这个植物-草食动物系统中，三个营养级别的物种之间存在微妙的相互作用。行会（嚼叶者和采叶者）之间的间接负面相互作用是通过寄生率的变化而不是通过基于资源的com？请愿。
The influence of leaf characteristics on host leaf selection and survivorship in an en- dophagous insect were studied in a leaf-mining species, Stilbosis juvantis. Dry mass measurements of mined and unmined leaves (after abscission) showed that the leaf miner does not select leaves for oviposition and subsequent larval feeding based on leaf size, possibly because densities of S. juvantis are typically low and this miner consumes only a small part of a leaf. However, censuses of 18 host trees, on 6 of which the proportion of damaged leaves had been experimentally increased, revealed that these leaf miners do select significantly more intact leaves than damaged ones for oviposition. S. juvantis on damaged leaves experienced significantly lower survivorship, owing to increased parasitism, than did miners on intact leaves. The higher rate of attack by parasitoids is probably attributable to physical or chemical alterations in damaged leaves. Thus, damage to leaves by previous herbivores modifies leaf selection by miners. These results indicate a subtle interaction among species at three trophic levels in this plant-herbivore system. Indirect negative interactions occur between guilds (leaf chewers and leaf miners) via changes in rates of parasitism rather than through resource-based com? petition.