Distribution of Empoasca devastans and its egg parasites in the Indian Union

Abstract

The cotton jassid Empoasca devastans Distant has been reported as a major pest from all the cotton growing areas of the Indian Union. Its outbreaks have always been a difficult problem for the growers of cotton in the Punjab, and it has often resulted in the complete failure of this crop (Lal, 1941). This jassid also attacks other crops and ornamental plants (Sohi, 1964). A systematic survey of various stages of this jassid was undertaken in the Indian Union by collecting the natural parasites and predators during the period May 1964 to September 1966. We have restricted the survey to the following crops: okra (Abelmoschus esculentus), castor (Ricinus communis), eggplant (Solanum melongena), cotton (Gossypium spp.) and cowpea (Vigna catjang). Five mymarid and one trichogrammatid parasites and four predators were found and recorded (Subba Rao et al., 1965; Subba Rao, 1966), and a new species of egg parasite was described. The material collected from different areas of the survey (Fig. 1) was kept in the laboratory in 15 × 20 cm jars. Any parasites hatching from the material were preserved in 70% alcohol. In addition an assessment of the % parasitism of the eggs of this jassid at Delhi was made for one year from August 1965 to July 1966 on the two seasonal crops, okra and eggplant, and on castor which is available throughout the year. Leaves gathered on the fields of the Institute were dissected in search of the jassid eggs. The visibly parasitised eggs were sorted out and counted.