Structure of tortricid-parasitoid community in blueberry crop of Buenos Aires, Argentina.

ROCCA M.; GRECO, N.

Pucón

Simposio; 4th International Symposium on Biological Control of Arthropods.; 2013

Pontificia Universidad de Chile

The species of tortricids more abundant in blueberries are exophytic leaf and flower feedings, (including leaf-rollers) and is expected to find greater richness of parasitoids koinobionts. As a newly introduced crop in Argentina, is probable that food webs in this crop have low complexity. We described the composition of parasitoid guilds and obtained the tortricid-parasitoid food web metrics. Sixty samples were taken monthly during three years in four blueberry fields of Buenos Aires. Parasitoid guilds were recognized following the classification made by Mills (1992). Four species of tortricids and five species of parasitoids were identified. Three parasitoid species were larval koinobiont endoparasitoids, two pupal idiobiont endoparasitoids, and one gregarious ectoparasitoid. Four guilds were registered: larval, early larval?prepupa, mid larval ectoparasitoid, pupal endoparasitoid. Early larval?prepupa guild caused the highest percentage of parasitism. The rate of species in the food web showed a trend in favor of the parasitoids, there are 2 species of parasitoids for each species of tortricid. The connectance was 0.086, the density of joints was 0.78, the number of real joints was 7, and the Berger-Parker index was 0.73 for tortricids and 0.59 for parasitoids. The richness of koinobionts was similar to that of idiobionts and mostly parasitoids were endoparasitoids. The values of food web metrics suggest that these communities have low complexity and would be susceptible to climatic and anthropogenic perturbations arising from crop management.