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.