Pala Ram ¹, R. K. Saini ¹

Affiliations
1 Department of Entomology, CCS Haryana Agricultural University, Hisar 125 004, Haryana, IN

Abstract

Observations on field incidence of solenopsis mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) attacking cotton and the predators and parasitoids associated with it were recorded in the cotton growing belt of Haryana state by conducting monthly surveys during 2008 and 2009. To assess the impact of primary and secondary parasitoids on the population of the solenopsis mealybug, parameters like severity of pest incidence, abundance of predators and parasitoids and parasitism/hyperparasitism by various parasitoids were taken into consideration. One primary parasitoid, Aenasius bambawalei Hayat, and four hyperparasitoids were recovered. The most abundant and dominant hyperparasitoid was Myiocnema comperei Ashmead, while the other three were of lesser importance. Similarly, out of six predators recovered from mealybug colonies, Brumoides suturalis (Fabricius) and Nephus regularis Sicard were more abundant. During 2008, in the absence of the primary parasitoid, A. bambawalei, mealybug incidence was quite high on cotton. However, during 2009, as the activity of the primary parasitoid increased, the pest population reduced significantly and its incidence was confined to only 18% of the fields and 1.6% of the plants by August. During mid-season (July-August), A. bambawalei was attacked by several species of hyperparasitoids, particularly M. comperei, which caused considerable reduction in its population during August. This resulted in the resurgence of solenopsis mealybug, though on a lower scale, during September-October.

Keywords

Aenasius bambawalei, Cotton, Parasitoids, Predators, Phenacoccus solenopsis, Myiocnema comperei, Biological Control.

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G. Kavitha ¹, P. Ram ¹, R. K. Saini ¹

Affiliations
1 Department of Entomology, CCS Haryana Agricultural University Hisar 125004, Haryana, IN

Abstract

Three strip crops, namely, maize, sorghum and cowpea were evaluated for their role in the enhancement of arthropod predators and reduction in pest populations in cotton and were compared with a control (cotton alone). Populations of arthropod predators such as spiders, coccinellids, green lacewing and rove beetles as well as insect-pests such as leafhopper, whitefly and aphid were recorded on cotton. Boll infestation due to spotted bollworm and pink bollworm was determined in opened cotton bolls at harvest. Among different strip crops, maize supported the highest number of predators (16.06 per 10 plants) as compared to control (10.73). Cotton strip cropped with sorghum (16.74) and maize (14.68) recorded the higher number of predators per 10 plants over control (10.23). Leafhopper population was significantly low in all the treatments as compared to control. Pink bollworm incidence was significantly low in cotton stripcropped with maize (17.4%) as compared to control (27.23%). However, different treatments bad no significant effect on aphid, whitefly and spotted bollworm incidence.

Keywords

Arthropod Predators, Cotton, Insect-Pests, Strip Crops.

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