Abstract:
The black headed hairy caterpillar, Pericallia ricini Fab., is a polyphagour pest feeding on a wide variety of crops such as castor, cotton, banana, cucurbits, sunflower, field beans, and gingelly. The occurrence of a granulosis in this insect was recorded in 1972, but no detailed studies have so far been made on this disease. A through knowledge of the disease including the host pathogen relationships and the physico-chemical properties of the pathogen is essential to judge its suitability in practical pest management programmes. With a view to collect these information the present studies were taken up.
Studies were made in the laboratory and in field cages. Larvas of P. ricini reared in the laboratory on castor leaves were used. Third instar larvas were used in all studies except those on symptamatology and larval susceptibility. A purified suspension of granules derived from 300 dead larvae in 3 litres of distilled water formed the inoculam. All the experiment were conducted at room temperature and humidity.
