Composition of entomophagous arthropods associated to different genotypes of grain sorghum in the cerrado of Southeast Brazil

In the present work we studied the abundance of entomophagous arthropods in panicles of sorghum genotypes in Selvíria, MS. Three experiments were conducted under field conditions and the genotypes were sowed in March/1988, October/1988 and February/1989, respectively. For subsequent counts of entomophagous arthropods, 560 panicles were marked per genotype in the beginning of the flowering. In the sequence, 40 panicles per genotype were collected daily for the next 14 days and placed in 10-litre bags. These bags were taken to the Laboratory of Entomology of FEIS/UNESP, for separation, counting and identification of the collected arthropods. Larger numbers of entomophagous arthropods were collected in sorghum sowed in the dry season than in that sowed in the wet season. Among the entomophagous arthropods collected, the spiders represented the larger number of species and these included the orb weaver Alpaida veniliae (Keys.), the nocturnal running spider Cheiracanthium inclusum (Blackwall), and the ambusher Misumenops pallidus (Keys.) as the most abundant species; the sorghum genotype IPA-201 was the most attractive to Orius sp. and Doru lineare (Eschs.), while IAC-83/75-5-1-6 presented medium attractiveness to D. lineare; spiders were collected in larger numbers in the genotypes BR-300 and SART.

Insecta; Araneae; biological control; extrinsic resistance