Suppression of Seed Beetle (<i>Callosobruchus maculatus</i>) Population with Root Bark Powder of <i>Zanthoxylum Zanthoxyloides</i> (Lam.) Waterm. (Rutaceae) on Cowpea (<i>Vigna unguiculata</i> (L.) Walp

Abstract

In view of the recently increased interest in developing botanical pesticides as an alternative to synthetic pesticides, this investigation was carried out to examine the insecticidal potentials of the Zanthoxylum Zanthoxyloides (Lam.) Waterm. (Rutaceae) Root Bark Powder against Seed Beetle, Callosobruchus 0 maculatus (F.). The experiment was carried out at ambient temperature of 28±3 C and relative humidity of 68±3% in the laboratory. Population suppression activities of Z. zanthoxyloides Root Bark Powder against Seed Beetle was recorded at 5, 7 and 10 g/150 g cowpea grains laid out in completely randomized design replicated four times including the untreated control. Plant products applied at rates greater than 20% of the grain weight would not be economically viable in suppressing the population of insect pests. The root bark powder was applied to assess contact adult mortality, adult emergence, percentage weight loss and percentage grains damaged. Application rates of Z. zanthoxyloides were found to possess insecticidal activity against adult seed beetle. Topical application of the root bark powder caused significant (P<0.05) increase in adult mortality, reduced adult emergence, reduced weight loss of the grains and offered protection of cowpea grains against damage in small scale storage. Highest rate of treatment significantly increased adult mortality of C. maculatus compared to lower rates at 2 DAT. From the results, it could be concluded that the adults of C. maculatus were susceptible to Z. zanthoxyloides root bark powder. On the whole application of the plant material was better than no treatment at all. Such findings would be helpful in promoting research aimed at the development of new agents for C. maculatus control. The plant powder could also, be incorporated in Integrated Pest Management approach against C. maculatus in storage.

Suppression of damaging effects of <i>Callosobruchus maculatus</i> (F.) (Coleoptera: Chrysomelidae) by plant powders

“…The results of this study agree with the findings of Idoko and Adesina (2012) who reported that P. guineense caused the mortality of C. maculatus adults and eventual suppression of progeny emergence due to contact toxicity of the powder. Previous investigation showed that mortality of C. maculatus increased with increase in the rate of plant part powder applied with higher rate assumed to be having higher active ingredients against the insect (Musa, 2012). The adult mortality recorded might be attributed to the leaf powders that may have caused abrasion of the insect cuticle.…”

Influence of selected legume seeds on emergence of <i>Callosobruchus maculatus</i> (F.) and its susceptability to <i>Azadirachta indica </i> (A. Juss) aqueous leaf extracts

“…It can however also infest several other types of stored legume grains such as chickpea, bambara nut, mung bean, groundnut and soybean (Ekeh et al, 2013) to varying degrees. When C. maculatus attacks stored legume seeds, they deface them with eggs and holes and invariably cause a reduction in their market and nutritional value (Musa, 2012).…”

Peel and leaf powders of three fruits and a vegetable as promising botanicals against Callosobruchus maculatus (F.)

“…Insect pests constitute the most visible and important constraint to cowpea production, infesting mature pods and accounting for post-harvest reduction of grains (Musa, 2012). Cowpea is infested by bean beetle, Callosobruchus maculatus (F.) between harvest and storage leading to quantitative and qualitative losses of grains.…”