Feeding Efficacy of Spiders on Sucking Complex of Okra, Abelmoschus Esculentus L.

Abstract:

The experiment was conducted to check the population of sucking insect pests such as; jassid, A. bigutella bigutella (Ishida) whitefly, B. tabacci (G), thrips, T. tabaci (S.) and mites, T. cinnabarinus (Boisd.) in a field condition of okra crop. Homogenous seeds of okra were drilled in rows 75cm apart from each other on well prepared seed bed on February 15, 2011. Where as, the feeding potential of predatory spiders on these pests were evaluated in a laboratory condition. Four prominent predatory spider species such as; Hippasa agelenoides, Cheiracanthium danieli, Argyrodes argentatus and Drassodes sp. were recorded throughout the data collection. Thus, there feeding potential was observed under the laboratory conditions at 25±2^oC and the pests were provided. The overall consumption by these two spider species; C. danieli and H. agelenoides consumed maximum (12.30±1.23) and (10.10±1.07) where as, the minimum (9.65±1.39) and (8.35±2.09) pest population by A, argentatus and Drassodes sp. The correlation of all predatory spiders was highly significant with jassid (r²=0.84**), whitefly (r²=0.94**), thrips (r²=0.88**) and mites (r²=0.94**). But the temperature had the low positive correlation with the population among predatory spiders (r²=0.45^ns), jassid (r²=0.38^ns), whitefly (r²=0.46^ns), thrips (r²=0.45^ns) and mites (r²=0.53^ns). In the behavior of relative humidity had also low positive correlation with the population of predatory spiders (r²=0.31^ns), jassid (r²=0.14^ns), whitefly (r²=0.25ns), thrips (r²=0.34^ns) and mites (r²=0.22^ns). However, predatory spiders were found abundantly with their carnivorous habits among the population that showed synchronization with the sucking insect pests in okra crop.