Controlling bruchid pests of stored cowpea seeds with dried leaves of Artemisia annua and two other common botanicals

Abstract

Insecticidal activities of dried Artemisia annua L. leaves were evaluated against bruchid (Callosobruchus maculatus F.) pests in comparison with those of Azadirachta indica, Ocimum gratissimum and a conventional grain storage insecticide, Actellic® 2% dust. Each treatment was added to a mixture of 250 g cowpea seeds and 25 adult bruchids and laid out in a completely randomized design with four replicates. Irrespective of the concentration tested, all three plant materials significantly (P < 0.05) increased mortality rate of adult insects earlier than the control. Higher concentrations of the botanical pesticides equally resulted in an increased reduction in the number of surviving bruchids and reduction to seed damage through a lower number of eggs laid and weevil perforation index (WPI) after 90 days. Comparatively, A. annua was more effective than the other plant materials at all levels evaluated though it was not as effective as Actellic 2% dust. Moreover, differences amongst the efficiency rates and interactions between A. annua and A. indica in three treatment combinations produced a significant (P < 0.05) effect on two of the parameters evaluated. Taken together, all plant materials evaluated here were seen to have significant insecticidal properties and could therefore, be used as environmentally friendly products for controlling bruchid pests during storage of cowpeas with no adverse effects on eventual mammalian consumers as observed during an animal feeding trial in this study.

The Efficacy of Ocimum gratissimum Leaf Powder and Ethanol Extract on Adult Periplanata americana under Laboratory Condition

“…However, no significant difference exists between V. amygdalina and A. indica leaf powder and between V. amygdalina leaf powder and the control. In contrast to the findings of Brisibe et al, [51] who reported that, of the three botanical pesticides (A. annua; A. indica and Open Access Library Journal O. gratissimum) tested, the highest adult insect mortality rate was recorded in the treatment with the highest concentration (20 g/250g cowpea seeds) of dried and pulverized leaves respectively. They reported that at the concentration of 5 g of the tested botanicals, no significant difference existed among them but in the present study, the treatment with the highest concentration of 5 g of the leaf powders of A. indica on 30 g of cowpea seeds caused a significant difference in the mortality of C. maculatus.…”

Insecticidal Actions of Some Botanicals to Storage Bruchid, Callosobruchus Maculatus (F.) on Stored Cowpea (<i>Vigna unguiculata</i> L. WALP.) Ogbaji Moses and Osuman Dorathy

“…The pungent and offensive odour of these plant materials may have caused an unconducive environment for the insects to reproduce. The results of this study are in total conformity with results obtained by Ebiamadon et al, 2011. Ebiamodon et al, 2011 why controlling bruchid pests of stored cowpea seeds using dried leaves of bitter leaf reported that the insecticidal activity of bitter leaf (vernonia amygdalina) was because it contained fairly high levels of bioactive constituents with fumigant activity which made it to have potent insecticidal properties. Also, Schmuhener and Ascher (1984), while working on another botanical, reported that the insecticidal activities of neem (Azadirachta indica) was a result of the presence of highly oxidized tetrapenoids, azadirachtin, salanin and other active products that posses repellant, antifeedant and growth disruptive properties against various insect species particularly C. maculatus.…”

Efficacy of Azadirachta indica Leaf Powder and Ethanol Extract on Adult Periplanata americana under Laboratory Condition

“…Moses and Dorathy [43] reported that bitter leaf gave the best protection against cowpea weevil when compared with garlic and ginger. They also reported that the significant difference (P < 0.05) obtained in the mortality of C. maculatus by comparing the efficacy of A. indica leaf powder with the control is an indication that A. indica leaf powder has some insecticide properties capable of controlling pests of stored Brisibe et al [45] reported that, of the three botanical pesticides (A. annua; A. indica and O. gratissimum) tested, the highest adult insect mortality rate was recorded in the treatment with the highest concentration (20 g/250g cowpea seeds) of dried and pulverized leaves respectively. They reported that at the concentration of 5 g of the tested botanicals, no significant difference existed among them but in the present study, the treatment with the highest concentration of 5 g of the leaf powders of A. indica on 30 g of cowpea seeds caused a significant difference in the mortality of C. maculatus.…”