Spiders in different agro-ecosystems in Argentina: Past, Present and Future?.

GONZÁLEZ, A.; CORRONCA, J. A.; ARGAÑARÁS, M. F.; OLIVO VERÓNICA,; GONZÁLEZ REYES, ANDREA XIMENA; ARMENDANO, A.

San Pedro Brasil

Simposio; XVII International Arachnological Congress; 2007

ISA

In the last decades the interest to study the spiders in agroecosystem increased, and in Argentina the first studies began in the middle of the ´90. Spiders as a generalist predator are important as natural enemies of pest insects in different crops. Several studies to prove it was carried out worldwide. In our country, the first study on this topic was made in cotton (Chaco Province). The last years, these studies have been made in: cotton (La Rioja province); in soybean, alfalfa and wheat crop (Buenos Aires) and in soybean, strawberry, pea and fruit trees orchards (tuna, citrus, fig and peach tree) (Tucuman-Salta provinces). Different collecting methods were used to collect spiders (beating net; pitfall trapping, G-vac, etc.) in crops and plots with different management (conventional vs. transgenic; few vs. high pesticides applications; conventional vs. non-tillage system); size of the plots (1-2ha, 3-5ha, 30-60-120ha) and different adjacent habitat (hedgerow, windscreen, natural forest patch, etc.). More than 35.000 spiders were collected of 125 species/morphospecies. The relationship of the spider diversity and guild composition on each crop are given in a comparative manner in the studied situations of management and size plot for the same crop and the importance of the adjacent habitat as a refuge for the spiders and the colonization/re-colonization is showing in different size plots and with different adjacent habitat heterogeneity, too. All the studies showed the spider diversity was high in the crop plots and guild composition was different according with the crop and the geographic area of the country. The spider community changed during crop phenology, applications of pesticides and where high heterogeneous surrounding habitats were present near the crop plots. The future for these studies in Argentina is promissory. New students and researchers are beginning studies to deep the actually known results and to investigate the spider role as natural enemies of key pests; diet and feed preferences, effect of the adjacent habitat heterogeneity and behavioural topics. All of them to improve their use into Integrated Pest Management programs in our country.