Stiling Peter, Simberloff Daniel, Brodbeck Brent V
Department of Biological Science, Florida State Univeristy, 32306-2043, Tallahassee, FL, USA.
Oecologia. 1991 Nov;88(3):367-370. doi: 10.1007/BF00317580.
At Sand Lake, Leon County, Florida, mines of Stilbosis quadricustatella, a leaf-mining moth, occur on sand live oak trees (Quercus geminata) over a broad range of densities. Some trees have fewer than 2% of their leaves mined (lightly infested), others up to 70% (heavily infested). Similar levels of infestation are maintained on the same trees year after year. There are no significant negative correlations of miner density per tree with any mortality factor that might explain miner preferences for certain trees. Nor is there a positive correlation with host leaf quality as measured by foliar nitrogen or by total or individual amino acid concentrations of host leaves. Egg-transfer experiments showed that larvae from eggs transferred to lightly infested trees were more likely to be killed by leaf abscission than were those that were transferred to and developed on heavily infested trees. This is the first demonstration that variation in rates of leaf abscission could be an important cause of the observed distribution pattern of sessile insects between conspecific host plants.
在佛罗里达州莱昂县的桑德湖，一种潜叶蛾——四斑潜蛾（Stilbosis quadricustatella）的虫瘿出现在沙生栎树（Quercus geminata）上，其密度范围很广。一些树木的叶片被虫瘿侵害的比例不到2%（轻度侵染），而另一些则高达70%（重度侵染）。同一棵树上年复一年地保持着相似的侵染水平。每棵树上潜叶蛾幼虫的密度与任何可能解释潜叶蛾对某些树木偏好的死亡因素之间，均不存在显著的负相关。与通过叶片氮含量或寄主叶片的总氨基酸或单个氨基酸浓度衡量的寄主叶片质量之间，也没有正相关关系。卵转移实验表明，转移到轻度侵染树木上的卵所孵化出的幼虫，比转移到重度侵染树木上并在其上发育的幼虫，更有可能因叶片脱落而死亡。这首次证明，叶片脱落率的差异可能是导致固着性昆虫在同种寄主植物间观察到的分布模式的一个重要原因。
