Integration of Pyrethroid Insecticides Combined With Host Plant Resistance in the Management of the Larger Grain Borer, Prostephanus Truncatus (Horn) (Coleoptera: Bostrichidae), OnStored Maize, Zea Mays L.

Abstract

Eight maize varieties from International Institute for Tropical Agriculture (IITA) Ibadan and two from local market were analyzed for their chemical and physical compositions. Thereafter, They were evaluated in no-choice test at 29-36 o C and 51-85% R.H against four populations of adult Prostepanus. truncatus originating from three geographical locations in Nigeria and one from Ghana. The varieties exhibited varying degrees of susceptibility and loss to P. truncatus attack with Yellow Mangu Jos recording the largest insect population (12.78+1.2) and suffered highest weight loss (8.73+3.1%) and damage (17.58+3.1%). The maize varieties differed in their chemical and physical parameters and their responses to P. truncatus attack were significantly different (P < 0.05). There were positive and significant correlations between total adult population and carbohydrate level (r =0.506, P< 0.05), weight loss and carbohydrate (r = 0.503, P< 0.05). Results obtained from the treatment of susceptible varieties with the pyrethroid demonstrate the attractive potentials of Bifenthrin and Deltamethrin against the larger grain borer.