Biopesticide activity of crude extracts and fractions of <i>Calotropis procera Ait</i>. towards the groundnut seed-beetle <i>Caryedon serratus</i> Ol. (Coleoptera, Bruchidae)

Abstract

In preparation for designing a strategy of integrated management associated with post-harvest products in Senegal, the bioactivity of crude and extracts of Calotropis procera Ait. on the survival of eggs and adults Caryedon serratus (Ol.) pest of groundnut, Arachis hypogaea L., was studied under controlled conditions. The crude extracts (ether and methanol) and fractions of extract (hexane, ethyl acetate and methanol) were applied through contact with C. serratus at different concentrations C 1 (0.1 g of dry residue / ml of solvent dilution), C 2 (0.01 g/ml) and C 3 (0.001 g/ml). The action of each biocid extract of C. procera on the survival of treated is dependent on the concentration and varies with the polarity of the extract. All concentrations induce high mortality of C. serratus eggs and adults regardless of the sample in use. The most important (86.14 ± 4.21%) adulticidal action was noted in 10 days of treatment with the methanol fraction. The adulticidal effect of crude methanol extract on C. serratus was in the range of 74.10 ± 2.82%. The biological activity of extracts of C. procera on the insect is also expressed by an imbalance of sex-ratio in favor of males, an extension or a reduction in the duration of the phases of development, reduced fecundity and fertility limited. The fecundity averages, less important, were obtained with the hexane fraction (44.83 ± 3.01 eggs) and high concentrations of ethyl acetate fraction (35 ± 0.71 eggs) or a respective rate of reduction of spawning 52.93% and 63.25% compared to the control. After characterization of reactions, it is clear from this study that the bioactivity of extracts of C. procera is likely related to suspected active compounds (alkaloids, flavonoids, tannins, anthracene derivatives, saponins, sterols and terpenes) as revealed from staining or precipitation using specific reagents.

Biocidal Effect of Leaves of &lt;i&gt;Crataeva religiosa&lt;/i&gt; Forst on a Resistant Strain of Groundnut Bean &lt;i&gt;Caryedon serratus&lt;/i&gt; (Olivier)

“…Thiaw and Sembene [18] which showed the effect of extracts of C. procera on the insect C. serratus expressing a sex ratio in favor of the males which causes a decrease of the increase of the population.…”

Experimental study of the effects of an aqueous solution of Eucalyptus alba leaves on the development of Callosobruchus maculatus, a pest of bean (Cowpea) stocks in Senegal (West Africa)

“…Like aqueous solutions of leaves and stems of Anogeissus leiocarpus and Mitragyna inermis which attenuated the peak proliferation of caterpillars, potential pests of cotton fields, at D49 compared to the control, with concentrations of 0.208 kg/ l and 0.104 kg/l [8] , the Eucalyptus alba leaf solution of 0.2 g per milliliter also retards the development of Callosobruchus maculatus by being able to lengthen the average development cycle of Callosobruchus maculatus at 26 days compared to normality (23 to 24 days). The use of the aqueous solution of this plant with a view to limiting the destruction of bean stocks is therefore effective, especially judicious in a context where the products intended for the chemical fight against crop pests are toxic to humans, pets, fish or game [14] .…”

Comparative biocidal effect of BioArt and Crataeva religiosa extracts against the groundnut seed pest Caryedon serratus (OL.) in Senegal

“…It is also one of the crops that makes the greatest contribution to meeting the nutritional needs (particularly protein and calories) of the people of West Africa. However, it is attacked by a number of insects, the most dreaded of which is Caryedon serratus (Olivier), responsible for quantitative losses of up to 83% after a storage period of 4 months [1,2]. The holes left by the larvae of C. serratus facilitate the attack of other insects which reduce the nutritional quality of the groundnut and encourage the development of a mould, Aspergillus flavus, which produces aflatoxin, which is highly carcinogenic.…”