Interactions Among Three Trophic Levels and Diversity of Parasitoids: A Case of Top-Down Processes in Mexican Tropical Dry Forest

摘要: The objective of this study was to analyze the relationship between plant hosts, galling insects, and their parasitoids in a tropical dry forest at Chamela-Cuixmala Biosphere Reserve western Mexico. In 120 transects 30 by 5 m (60 deciduous 60 riparian habitats), 29 insects species were found represented following order: Diptera (Cecidomyiidae, which induced greatest abundance galls with 22 species; 76%), Homoptera (Psylloidea, 6.9%; Psyllidae, Triozidae, 3.4%), Hymenoptera (Tanaostigmatidae, 3.4%; rare), one unidentified morphospecies (3.4%). all cases, there great specificity insect host associated specific species. contrast, no parasitoid Only 11 families: Torymidae (18.2%), Eurytomidae Eulophidae Eupelmidae (9.1%), Pteromalidae family Braconidae Platygastridae (9.1%). Most parasitized several gall (Torymus sp.: 51.1%, Eurytoma 49.7%, Torymoides 46.9%). Therefore, effects variation defenses do not extend third trophic level, because few can determine community structure composition plants, instead, top-down processes seem be regulating interactions communities.