Influence of temperature and humidity on populations of Callosobruchus maculatus (Coleoptera: Bruchidae) and its parasitoid Dinarmus basalis (Pteromalidae) in two climatic zones of Burkina Faso

Abstract

Callosobruchus maculatus (Fabricius) develops in the seeds of Vigna unguiculata in the Sahel region of Africa. The reproductive activity of this species and the development of its offspring were studied during the dry season at Ouagadougou and Bobo Dioulasso (Burkina Faso), two zones with different climatic conditions. The length of imaginal life of the females and the developmental time varied with changes in climatic conditions, the lowest values for both parameters being found at the end of the dry season when temperature and humidity increased. In the two zones, variations in the density of the bruchid populations have been studied in experimental stores. The density of the bruchid population was low at the beginning of the study and increased when temperature and humidity rose. The introduction of Dinarmus basalis (Rondani) adults to the stores caused a significant reduction in the numbers of C, maculatus adults. The density of the D. basalis populations was low from December to February and increased when temperatures and then humidity became higher. The increase of the D. basalis population and the rate of parasitism were greater at Bobo Dioulasso than at Ouagadougou. Laboratory studies have demonstrated that fecundity, duration of adult life and developmental times depend on humidity. This study has shown the importance of local climatic conditions on parasitoid reproduction and development and also in the control of bruchid populations in stores.

Competition in the Parasitization of Callosobruchus maculatus between Dinarmus basalis and Choetospila elegans on Vigna unguiculata (Walp.) Seeds

“…The time of introduction of the parasitoid wasps was very crucial in arresting the vulnerable stages of the bruchids which are the larval, the pre-pupa and the pupal stages. The introduction of parasitoids from three to six days (when the eggs are presumed hatched (Ouedraogo et al, 1996) to 20 days after the grains were infested apparently allowed for the proper life stage (early and late instar larvae) to be present for parasitization, and gave the parasitoid population a boost compared to the growth rate of the pest population. This study has also showed that the presence of more than one parasitoid in mixture gave more efficient control of the bruchids in the local bin than when one parasitoid species was present.…”

“…According to IITA (1989) C. maculatus consumes 50-90% of cowpea in storage annually throughout tropical Africa. The bruchid infestation also affects seed quality, market value and can reduce cowpea seed viability to 2% after three months of storage (Ofuya & Credland, 1995;Ukeh et al, 2011 Ouedraogo et al (1996) the life cycle of C. maculatus takes about 4-5 weeks and about 6-7 generations are quite common in many countries. A female lays about 90-100 eggs in her lifetime.…”

“…The adult insect lives for about 4-5 weeks. Species of natural enemies are associated with stored-product insects (Brower et al, 1996) and their potential as biological agents for these pests have been widely studied (Ouedraogo et al, 1996;Donnelly & and Philips, 2001;Amevoin et al, 2007;Iloba et al, 2007). In West Africa (Niger, Burkina Faso, Benin) the solitary ectoparasitoid Dinarmus basalis Rendani (Hymenoptera: Ptermalidae) and its sympatric species Eupelmus vuilleti Crawford and E. orientalis Crawford (Hymenoptera: Eupelmidae) parasitize the larvae and pupae of C. maculatus (F.) and Bruchidius atrolineatus (Pic) (Coleoptera: Bruchidae) which develop inside the seeds of V. unguiculata (Danielle Rojas-Rousse, 2010).…”

Evaluation of the insecticidal effects of <i>Hyptis suaveolens</i> (L.) for the management of <i>Callosobruchus maculatus</i> (F.) on two varieties of cowpea, <i>Vigna unguiculata</i> walp

“…It is a field -to-store pest as its infestation of cowpea often begins in the field as the mature pods dry (Huignard et al, 1985;Sathyaseelan et al, 2008) and when such seeds are harvested and stored, the pest population increases rapidly and results in total destruction within a short duration of 3-4 months (Rahman and Talukder, 2006). It multiplies very rapidly in storage and has caused 8.5% loss in pulses during postharvest handling and storage in India (Ouedraogo et al, 1996). Insect infestation is a major contributor of quality deterioration of durables (cereals, pulses, and tubers) stored in warm and humid climates.…”

Effect of rearing season, host plants and their interaction on economical traits of tropical tasar silkworm, Antheraea mylitta Drury- an overview

“…of a particular place, which is governed by different geographical parameters (Murthy et al, 1996). Studies have shown the importance of seasonal variations in biology and development of insect (Odum, 1983;Ouedraogo et al, 1996). Insects are cold-blooded (Poikilothermic) organisms, so their body temperature is more or less same as that of their surrounding microenvironment.…”