The study was conducted to explore the biology of host Sitotrogacerealella Oliver (Lepidoptera: Gelechiidae) and its egg parasitoid Trichogrammaevanescens (Hymenoptera: Trichogrammatidae); effects of ecological factors especially temperature and relative humidity on both host and parasitoid as well as to explore the parasitization performance of the egg parasitoid reared on the eggs of S. cerealella.The experiment was conducted in the laboratory of the Department of Entomology at Sher-e-Bangla Agricultural University during the period from July 2010 to January 2011.The study was conducted using Complete Randomized Design (CRD) with various replications for various parameters.
Maintenance of Sitotrogacerealella stock culture
The anguimous grain moths/rice moths (S. cerealella) were reared on unhusked wheat grains in the metallic rearing cage (specially made for rearing of rice moth) egg parasitoid T. evanescens.
Biology study of Sitotrogacerealella
The eggs of S. cerealella from the stock culture were used to rear in the wheat grains. The experiment was replicated 5 times for each parameter during each month of the study period.
Viability test of the Sitotroga eggs
Viability test of the eggs laid by S. cerealella were tested considering the variable ages of eggs after laid.
Maintenance of Trichogrammaevanescens stock culture
The inoculum of egg parasitoid Trichogrammaevanescens were collected from the Safe Agro-Bio Tech Ltd, Mirpur, Dhaka, Bangladesh.
Biology study of Trichogrammaevanescens
The eggs of S. cerealella from the stock culture were kept in glass vial in the laboratory at ambient room conditions.
Parasitizing performance of T. evanescens
The pre-designed number such as 40, 35, 30, 25 and 20 of Trichogramma parasitized host eggs were released for each 100 Sitotroga eggs separately kept in the glass vials.
Variations of parasitization performance during study period
The definite number (20) of Trichogramma parasitized host eggs were released for each 100 Sitotroga eggs separately kept in the glass vials. This study was continued upto January 2011 starting from September 2010.
Data recorded on weather factors
During the experimental period from August 2010 to January 2011, the weather data such as temperature and relative humidity of the ambient room condition of the laboratory were recorded for each day of the months.
Statistical analysis
The data obtained for different parameters were statistically analyzed to find out the significant difference.