The Effect of Temperature, Concentration and Time on Efficiency of Entomopathogenic Nematode Steinernema feltiae Against Flour Beetle, Tribolium confusum Under Laboratory Conditions
Currently, chemical pesticides and radioactive rays are widely used for control of stored product pests. Fumigation plays a major role in insect pest elimination in stored products. Phosphine and methyl bromide are the two common fumigants used for stored-product protection world over. Insect resistance to phosphine is a global issue now and control failures have been reported in field situations in some countries. Methyl bromide, a broad-spectrum fumigant, has been declared an ozone-depleting substance and, therefore, is being phased out completely. In view of the problems with the current fumigants, there is a global interest in alternative strategies including development of biological control. An experiment was performed to determine the effectiveness of Steinernema feltiae on adults of flour beetle (Tribolium confusum Duval) under laboratory conditions. The activity of entomopathogenic nematode was evaluated at five different concentrations (0, 25, 50, 100 and 200 infective juveniles per insect) in four different temperatures (25, 27.5, 30 and 32.5 ºC ±0.5). Insects were placed on filter paper impregnated with 1 ml of suspension in 9 cm petri dishes, and dead insects were counted every 24 h. The Maximum mortality of the adults observed in 200 IJs/insect, after 72 hours of exposure at 27.5ºC was 67.5%.