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R. PRASANNA LAKSHMI, K. MANJULA* AND T. MURALIKRISHNA
Department of Entomology, S.V. Agricultural College, Tirupati-517 502, Andhra Pradesh, India
A field trial in RBD was conducted at S.V. Agricultural College, Tirupati to study the Positive influence of intercrops on coccinellid and spider fauna in groundnut during kharif 2011. The systems studied were groundnut + red gram, groundnut + castor (at 7 : 1 ratio), groundnut + cowpea, groundnut + field bean (at 6:1 ratio) and sole groundnut. Coccinellids and spiders were predominant during crop growth period. Various species of coccinellid predators were considered as a group, and their presence was recorded in all the cropping systems. All the spiders, irrespective of the family to which they belonged, were recorded together as one unit. Among the coccinellids, Chelomenes sexmaculata was the predominant predator which accounted for 70 per cent of the population. Spiders belonging to Lycosidae family were predominant. Population of coccinellids and spiders were increased up to 60 – 70 DAS and declined later. This may be due to availability of sufficient prey like aphids, jassids etc during vegetative stage of the crop. Change in microclimate due to shredded/shrinked foliage at later stages of the crop also may not favor the natural enemy fauna. The data showed that coccinellid population was comparatively high in groundnut + cowpea system (2.44 per plant). Aphids that prefer cowpea might have attracted the grubs and adults of coccinellids towards the crop, as coccinellids are the major predators of aphids. In the remaining intercrop systems also, significantly higher lady bird beetle population was observed. Spider population was comparatively higher in groundnut + field bean system (1.66 per plant) followed by groundnut + cowpea system (1.32 per plant). Other systems had 0.8-1.3 spiders per plant.
Coccinellids, Groundnut, Intercrop, Spiders, Sole crop.