Division of Entomology, Indian Agricultural Research Institute, New Delhi-110 012 (India).
During kharif 1999, a serious outbreak of Pyrilla perpusilla Walker was observed on sorghum. The population of Pyrilla varied from 50 to 200 adults/nymphs on 5th leaf of the plant. The population was brought down by the natural enemy, Epiricania melanoleuca Fletcher, appreciably. In all, 68 sorghum genotypes were observed for distribution of cocoons of E. melanoleuca. Number of cocoons varied from 2 to 83 on different genotypes. Twelve genotypes showed 0–10 cocoons on 5th Ieaf/plant. They were DPS-13, PS-309, PS-339, PG-31, DPS-29, DFS-1-1, DFS-12, DFS-10, DFS4, DST-3, PS-301 and PG-14. The range of cocoons on 5th leaf/plant varied greatly on different sorghum genotypes, viz, forty-one showed 11–30 cocoons, twelve exhibited 31–50 cocoons, two genotypes (PG-85, PS-306) showed 51–70 cocoons and only one genotype (PS 304) had 83 cocoons. It seems that the sorghum genotypes directly influenced the activity of natural enemies.
