Diversidad de Araneae en cultivos de Citrus sinensis (Rutaceae) de la provincia de Corrientes, Argentina

Abstract

El manejo integrado de plagas (MIP) es un método ecológico que tiene como objetivo

reducir o eliminar el uso de pesticidas y mini- mizar el impacto al medio ambiente (SAGPyA

2011). El MIP incluye como alternativa al con- trol biológico, mediante el cual no se tiende a

la erradicación de las plagas, sino a reducir la

densidad de las mismas para impedir que cau- sen daño económico. Es sabido que el éxito de

estos programas dependerá de estudios prelimi- nares sobre la biología y ecología del complejo

de enemigos naturales presentes en el cultivo (Bale et al. 2008).Spiders are predators that reduce insect pest populations in agroecosystems. In spite that the presence of spider assemblages has been described in different crop plants, no reports have been done for Citrus species in Argentina. We studied the spider community associated with cultures of Citrus sinensis in the province of Corrientes, Argentina, in two plots (AM1 irrigated and AM2 unirrigated) of 0.82 hectares each. Spiders were collected monthly by using pitfall traps, hand capture, agitation of foliage and sieving of soil litter. A total of 7174 specimens were collected (33 families, 44 genera and 200 species/morphospecies). The AM1 recorded

3811 individuals (33 families, 179 species/morphospecies) and AM2 3363 individuals (31 families, 174 spe- cies/morphospecies). November, December and January showed the highest abundance in both plots. A total of

70% of collected spiders were juveniles. Eight families were the most abundant and represented 75% of spiders collected in both plots, the largest being Lycosidae. We identified eight guilds in both plots, for which the ground runners resulted the most abundant (AM1 n=1341, s=39, n=999 AM2, s=33), followed by orb weavers

(AM1 n=637, s=36; AM2 n=552, s=33), the stalkers (AM1 n=471, s=43, AM2 n=453, s=47) and the space web- builders (AM1 n=446, s=23; AM2 n=342, s=25). The analysis of alpha diversity in both plots (AM1H’=4.161,

J’=0.802; AM2 H’=4.184, J’=0.811) showed no significant differences (t=1.083 p=0.279). The linear depen- dences model was the one with the best fit results, where the species observed were more than estimated. Clench

model estimated 90.9% of the spiders observed in the unit with irrigation and 90.6% in the unit without irriga- tion. Rev. Biol. Trop. 61 (3): 1243-1260. Epub 2013 September 01.