Biocontrol Laboratory Department of Entomology, G.B. Pant University of Agriculture and Technology, Pantnagar - 263 145, Uttarakhand, India.
* Corresponding author's address: Flat No. 14/1, Ellora Apratments, 2 Gariahat Road (S), Dhakuria, Kolkata (WB) – 700 068; E-mail: kulverma@rediffmail.com
The important naturally occurring egg parasitoids of Scirpophaga incertulas in Pantnagar region were Telenomus sp. and Tetrastichus sp. The mean percent parasitization was low in the early stages (15.38%), which increased progressively and remained constant in the middle of the season but increased during end of the season (73.56%). Egg parasitization by Telenomus sp. varied from 14.94 to 45.63% while, the egg parasitization by Tetrastichus sp. was in the range of 15.32 to 71.66%. In the early phases of crop growth, Telenomus sp. was more abundant and in the later period Tetrastichus sp. was dominant. The sex ratio of Telenomus sp. was in the range of 1:0.76 to 1:1.54, and that of Tetrastichus sp. varied from 1:0.75 to 1:1.35. The sex ratio of both the parasitoids was variable throughout the season.
