Performance of P. Truncatus Strains on maize varieties in choice and no-choice tests
EN Nwankwo, NJ Okonkwo, RI Egwuatu, Adibe FU, Ukonze CB, Obiefule IE, Asogwa JN
The larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) is the most damaging insect pest of maize, an important staple food crop for people living in sub-Saharan Africa. A laboratory assessment was conducted to evaluate the performance of P. truncatus originating from three geographical locations in Nigeria and one from Ghana on ten maize varieties in no-choice and choice test. Performance assessment of the strain in no-choice test was based on adult mortality, F1 adults, population density, body weight and size of F1 adults, developmental period, weight loss and damage. These parameters were significantly correlated with each other using Analysis of variance (ANOVA). Adult survival and subsequent damage was poorer on some varieties of maize. The extent of damage, loss and dust produced were significantly different (P<0.05) among the maize varieties. The order of the weight loss recorded for these varieties was Yellow Mangu Jos > Acr.91-SUWAN-1SRC1 > Western yellow > Oba Super I > Oba Super II > Yellow Popcorn > TZESR-W> Acr.89-DMR-ESR-W and Acr.97-TZL > BR 9928-DWR-SR-Y. P. truncatus from different geographical locations differed in some ways and their overall responses and performance on the different maize varieties were different although not significant (P> 0.05) in both choice and no-choice test. The developmental period of the Ibadan strain on the highly susceptible Yellow Mangu Jos was lowest (40.0+0.6 days) followed closely by the Enugu strain (40.7+0.7 days). P. truncatus from Benue and Ghana had longer mean developmental periods on the same variety, 45.3+0.3 and 47.0+0.0 days respectively.