Protozoology Laboratory, Department of Zoology, University of Kalyani, Kalayani, West Bengal, (India).
*Correspondence: Senior Scientist, Division of Parasitology, Indian Veterinary Research Institute, Izatnagar - 243 122, Uttar Pradesh, (India)
The effect of ingestion of Nosema sp. spores on growth, weight and mortality of Sitophilus oryzae was measured. At the dose of 4 × 108 spores/larva, 85.3% mortality was recorded after 288 h of infection. The LD50 value was determined as 2.8 × 105 spores/larvae at 288 h. At the highest dose a significant degree of weight loss was observed in larvae, pupae and adults. Nosema sp. spores also reduced the growth rate of larvae. Of the various doses ministered, 4.0 × 108 spores/individual proved to be effective. This dose produced a mean spore concentration of 9.72 ± 0.1 × 108 spores/larva.
