Tuesday, December 12, 2006

Herbivore insects associated with fruits of Schoepfia schreberi J.F. Gmel (Olacaceae) and their natural enemies

Maurilio Lopez, maulopez@uv.mx1, Francisco Diaz-Fleischer, fradiaz@uv.mx1, and Julio C. Rojas, jrojas@tap-ecosur.edu.mx2. (1) Universidad Veracruzana, Laboratorio de Biotecnologia y Ecologia Aplicada (LABIOTECA) Circuito los lagos s/n, Campus para la Cultura las Artes y el Deporte, Xalapa, Veracruz, Mexico, (2) ECOSUR, El Colegio de la Frontera Sur, Carretera Antiguo Aeropuerto Km. 2.5 Apdo. Postal 36, Tapachula, Chiapas, Mexico

A guild of insects associated with the fruits of Schoepfia schreberi were investigated in Veracruz, Mexico. A number of interactions of up to three levels between intraspecific and interspecific predators, parasitoids and competitors have been observed. The found herbivores were Anastrepha spatulata Stone (Diptera: Tephritidae), Ramosiana insignis (Blanchard) (Hemiptera: Pentatomidae), an unidentified species of moth (Lepidóptera) and Atta mexicana (F. Smith) (Hymenoptera: Formicidae). The immature stages of the three first species are fed on the fruits. Separate mention is the fact that A. mexicana harvest great amounts of fruit of S. schreberi with probable consequences for the other populations of insects. Anastrepha Spatulata and moth use the fruits to lay eggs respectively when these weigh between 0.0254-0.0637 g and 0.0583-0.0637 g. R. insignis is fed on the fruits when these weigh between 0.0583-0.0951 g. 1680 fruits were collected to determine % of infestation and to gain access the insects emerged from these fruits, of a 51% (n=864) of the total of the infested fruits the 86,34% (n=746) of the emerged insects pertained to individuals of A. spatulata, whereas the rest the 13,66% (n=118) of the emerged insects were moths. The natural enemies for A. spatulata were 3 species of parasitoids, for moth 2 species of parasitoids, all pertaining to the hymenoptera order and for R. insignis a species of parasitoid of the diptera order. Amount the predators we found two species of spiders of the family salticidae.

Species 1: Diptera Tephritidae Anastrepha spatulata (fruit fly)
Species 2: Hemiptera Pentatomidae Ramosiana insignis
Species 3: Hymenoptera Braconidae Doryctobracon areolatus (Parasitic wasp)