No abstract

Problems associated with synthetic pesticides have necessitated the search for an alternative pest control method. The effect of six coloured polyethylene films on Tribolium castaneum infestation on stored chips was studied in the Laboratory, from February to May, 2012. Three Musa spp (Agbagba, Obino'l ewai and cooking banana) were used. Dried chips (20 g) of each Musa spp were weighed into six different coloured perforated polyethylene bags (blue, red, yellow, green, black, and transparent) after further drying to constant moisture content in the oven. Ten adult beetles, comprising 5 males and 5 females were introduced into each bag tightly closed using rubber band. The experiment was a 6 × 3 factorial (6 colours polyethylene films by 3 Musa spp) laid out in a completely randomized design (CRD) with three replications. Results showed that there were significant differences amongst the three Musa species on the survival, progeny production and damage caused by T. castaneum. Survival counts of adult T. castaneum on chips stored in various coloured polyethylene bags within the period of 21 days did not differ significantly from one another. Generally all the coloured films reduced the abundance of T. castaneum on chips more than the colourless (transparent) films. Red coloured polybags significantly reduced beetles infestations and retained the highest weight of chips up to three months after infestation. Damage on chips stored in red coloured bags was significantly lower than those of yellow, green and transparent colours but did not differ with those of blue and black. Chips stored in transparent bags had the highest number of beetles and sustained the highest damage than other coloured polybags. Keywords

Musa spp are highly perishable crops with serious storage problems. Transformation to chips and flour has been identified as the only means of keeping them for a relatively longer period of time. This transformation, however, exposes them to attack by many storage pests including Tribolium castaneum Herbst. To get protection from these pests, in the past, synthetic pesticides were used with some measure of success. However, residue accumulation, toxicity to man and pest resistance caused by arbitrary use of synthetic pesticides have inspired this research into a healthy and less toxic alternative control measures for stored produce pests of chips. . The experiment was laid out as 8 × 3 factorial (8 levels of protectants by 3 levels of chips) in completely randomised design (CRD) with three replications. Results revealed that actellic (Primiphos methyl) had significantly (p < 0.05) higher mortality effect on adult T. castaneum than the other protectants. Chips treated with 2g cloves had significantly (p < 0.05) lower percentage loss and lower rate of damage than all the protectants but its effects was similar to that of actellic. 2g cloves therefore compared favourably with the synthetic pesticides against T. castaneum in chips storage.