ABSTRACT Larvae of Leptus hringuri parasitizing families (adult female + offspring) of the treehopper Alchisme grossa on two host-plants, Brugmansia suaveolens (BS) and Solanum ursinum (SU), were studied. The effect of microenvironmental abiotic conditions (luminosity, temperature and relative humidity) and biotic conditions (distance from the soil to a treehopper host and host-plant phenological stage) on this tritrophic interaction was examined. Overall, the results suggest i) intensity of mite infestation (mean number of mites per infested female or family) of treehoppers (insect hosts) was twice on SU than on BS, ii) a preference of L. hringuri larvae for places with more luminosity (on both host-plants) and relative humidity (on SU), iii) a negative correlation between larval infestation and distance of the host colony to the ground, and iv) that larvae of L. hringuri could detect cues (i.e. chemical) emitted by their insect hosts or the host-plant of the insect host. Results indicate that luminosity, humidity and distance to the ground of the insect-host microenvironment affect both parasitization and prevalence of Leptus larvae mites; however, further research will be needed to understand the ecological mechanisms and consequences of these interactions and to test the hypotheses proposed herein under a chemical ecology perspective.

中文翻译：

---

Leptus hringuri Haitlinger, 2000 幼虫 (Trombidiformes: Erythraeidae) 对来自玻利维亚的树蝉 (Hemiptera: Membracidae) 对两种寄主植物物种的选定生态参数的响应

摘要 研究了寄生于两种寄主植物 Brugmansia suaveolens (BS) 和 Solanum ursinum (SU) 上的树蝉 Alchismegrossa 家族（成年雌性 + 后代）的 Leptus hringuri 幼虫。检查了微环境非生物条件（光度、温度和相对湿度）和生物条件（从土壤到树蝉宿主和宿主-植物物候阶段的距离）对这种三营养相互作用的影响。总体而言，结果表明 i) SU 上的树蝉（昆虫寄主）的螨虫侵染强度（每个受感染雌性或家庭的平均螨虫数量）是 BS 上的两倍，ii）L. hringuri 幼虫偏爱亮度更高的地方（在两种寄主植物上）和相对湿度（在 SU 上），iii) 幼虫侵染与寄主群体到地面的距离之间呈负相关，iv) L. hringuri 的幼虫可以检测到它们的昆虫宿主或昆虫宿主的宿主植物发出的线索（即化学物质）。结果表明，昆虫宿主微环境的光度、湿度和距地面的距离会影响 Leptus 幼虫螨的寄生和流行；然而，需要进一步研究以了解这些相互作用的生态机制和后果，并在化学生态学的角度测试本文提出的假设。