Indian Journal of Plant Protection
  • Year: 1988
  • Volume: 16
  • Issue: 2

Population Fluctuation of Earias Vittella (Fab. on Okra in Relation to Abiotic Factors

  • Author:
  • K. K. Kumar1, K. C. Devaraj Urs
  • Total Page Count: 6
  • Page Number: 137 to 142

Department of Entomology, University of Agricultural. Sciences, Bangalore, 560 065, Karnataka.

* A part of the Ph.D. thesis submitted by the first author to the University of Agricultural Sciences, Bangalore.

Abstract

Studies on the seasonal incidence of Earias vittella (Fab.) revealed that the infestation on okra shoots and fruits started in the second and sixth week after germination respectively. All the monthly sown crops recorded infestation on shoots from 3rd to 5tQ week during both the years of study. The infestation level on fruits varied from 8.4 to 53.8 and 9.2 to 73.2% in different weeks during 1983 - 84 and 1984 - 85 respectively. The pooled data showed the infestation level of the pest varying from 12.6 to 32.6 and 13.6 to 46.7% under different monthly sown crops in both the years respectively. The 10th week of 1983 - 84 and 11th week of 1984 - 85 sowings suffered heavily. The infestation was more severe in warmer months sowings as compared to rainy or cooler months sowings. There was a positive and significant correlation between the incidence and prevailing temperatures during respective weeks and months under observations. Relative humidity was found to be negatively correlated with the incidence, where as rainfall did not show any correlation.