The effects of copulation duration in the bruchid beetle Callosobruchus maculatus

Control over copulation duration is a potentially importantgenerator of sexual conflict that has received little empiricalattention. The copulatory behavior of the bruchid beetle Callosobruchusmaculatus may reflect a sexual conflict over copulation duration.Males have spines on their intromittent organs that puncturethe female reproductive tract, and females kick their matesduring copulation. If females are prevented from kicking, copulationslast longer and the injuries females sustain are more severe.Males supposedly use the spines as anchors to prolong copulationduration, and females kick to terminate copulations. We manipulatedcopulation duration experimentally and quantified its effectson male and female fitness components to test whether or notthere is a conflict over copulation duration in C. maculatus.Females did not suffer from long copulations but instead experiencedincreased lifetime fecundity. Ejaculate size increased withcopulation duration, and females apparently derive materialbenefits from the ejaculates. Males that mated first and hadlong copulations were relatively unsuccessful when competingwith sperm from other males. However, there was a trend forfemale remating propensity to decrease with long copulationdurations, and first males may therefore also benefit from longcopulations. The copulation duration of the second male to matedid not have a significant effect on sperm precedence. We concludethat even though it seems likely that the male spines have evolvedto act as an anchor during copulation, there seems to be littleconflict over copulation duration per se in C. maculatus.     

Intraspecific variation in sperm precedence in the bruchid beetle Callosobruchus maculatus

Abstract.

• 1 By examining potential sources of intraspecific variation in sperm precedence, the underlying mechanisms of sperm competition in Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) were investigated.
• 2 The extent of sperm precedence was not related to either copulatory behaviour or body size (male and female).
• 3 The extent of sperm precedence increased during the egg-laying period, suggesting that the stratification of sperm within the spermatheca is not the mechanism of sperm precedence.
• 4 Direct removal of sperm from the female's reproductive tract was not observed.
• 5 Four other mechanisms (not mutually exclusive) are proposed to account for last-male sperm precedence in this species.

     

Influence of cowpea pod maturity on the oviposition choices and larval survival of a bruchid beetle Callosobruchus maculatus

The active or dispersing morph of Callosobruchus maculatus, a pest of stored cowpeas, is presumed to infest cowpea plants in the field prior to harvest. In oviposition choice tests, both normal and active females preferred pods that were full-size but still green over younger, smaller pods or older, mature pods. Exposed seeds were usually preferred over intact pods of all stages, although females laid more eggs on green pods than on the rough-coated seeds of one cowpea variety. Egg-to-adult survivorship was highest for eggs laid directly on seeds. On both green and mature pods high mortality occurred because newly hatched larvae failed to penetrate a seed after they drilled through the pod wall. However, since 20–50% of eggs laid on green pods do develop into adults, cowpea plants are susceptible to C. maculatus well before pods dehisce to expose the seeds. The oviposition preferences of C. maculatus may be strongly influenced by the surface texture of potential oviposition sites.

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Résumé La forme active de Callosobruchus maculatus, ennemi de Vigna unguiculata stocké, est suspectée d'infester les gousses dans les champs avant la récolte. Lors d'essais sur le choix du lieu de ponte, toutes les femelles, normales et actives, ont préféré les gousses encore vertes mais ayant atteint leur taille définitive aux gousses plus jeunes ou aux gousses plus âgées (jaunes) ou mûres. Les graines étaient presque toujours préférées aux gousses à tous les stades, mais quand les graines étaient rugueuses, elles pondaient de préférence sur les gousses vertes.Le pourcentage le plus élevé d'adultes a été obtenu à partir des oeufs pondus sur les graines. Avec les pontes sur gousses vertes ou mûres, la mortalité élevée se produisait lors de la pénétration dans la gousse. Néanmoins, comme 20 à 50% des oeufs pondus sur des gousses vertes donnent des adultes, V. unguiculata est susceptible d'être attaqué par C. maculatus bien avant la déhiscence des gousses et l'exposition des graines. L'évolution temporelle des propriétés physiques des gousses paraît à l'origine de la relation complexe entre l'âge et l'attractivité des gousses.

     

Genetic architecture of population differences in oviposition behaviour of the seed beetle Callosobruchus maculatus

Few studies have examined the genetic architecture of population differences in behaviour and its implications for population differentiation and adaptation. Even fewer have examined whether differences in genetic architecture depend on the environment in which organisms are reared or tested. We examined the genetic basis of differences in oviposition preference and egg dispersion between Asian (SI) and African (BF) populations of the seed beetle, Callosobruchus maculatus. We reared and tested females on each of two host legumes (cowpea and mung bean). The two populations differed in mean oviposition preference (BF females preferred cowpea seeds more strongly than did SI females) and egg dispersion (SI females distributed eggs more uniformly among seeds than did BF females). Observations of hybrid and backcross individuals indicated that only the population difference in oviposition preference could be explained by complete additivity, whereas substantial dominance and epistasis contributed to the differences in egg dispersion. Both rearing host and test host affected the relative magnitude of population differences in egg dispersion and the composite genetic effects. Our results thus demonstrate that the relative influence of epistasis and dominance on the behaviour of hybrids depends on the behaviour measured and that different aspects of insect oviposition are under different genetic control. In addition, the observed effect of rearing host and oviposition host on the relative importance of dominance and epistasis indicates that the genetic basis of population differences depends on the environment in which genes are expressed.     

Copulating with multiple mates enhances female fecundity but not egg-to-adult survival in the bruchid beetle Callosobruchus maculatus

Postcopulatory sexual selection theory has come a long way since the evolutionary implications of sperm competition were first spelled out by Parker (1970). However, one of the most enduring questions remains: why do females copulate with multiple males? Here we show that females copulating with multiple males lay more eggs than those copulating repeatedly with the same male. We also show egg‐to‐adult survival to be more variable when females copulate multiply with different males and less variable when they copulate multiply with the same male. This supports the notion that egg‐to‐adult survival may depend on the genetic compatibility of males and females. However, pre‐adult survival was highest when females copulated repeatedly with the same male rather than with different males. Thus, it would appear that polyandry in this species does not function to reduce the risk of embryo failure resulting from fertilization by genetically incompatible sperm.     

The function of multiple mating in oviposition and egg maturation in the seed beetle Callosobruchus maculatus

Abstract.  To comprehend the significance of multiple mating in female Callosobruchus maculatus , the material-benefits hypothesis is tested, as well as the potential function and mechanism of additional mating for females. The results show that longevity and lifetime fecundity are significantly higher in doubly-mated females, whereas females subject to an interrupted second copulation (which transfers no ejaculate) show resemblance with singly-mated females in lifetime fecundity and daily fecundity, supporting the material-benefits hypothesis. Female lifetime fecundity increases with ejaculate size in doubly-, but not singly-mated females. Doubly-mated females exhibit an immediate increase in fecundity on the day of remating. Moreover, dissection of ovaries after remating shows that the number of unlaid eggs is lower in doubly-mated females in comparison with singly-mated females, whereas the total number of unlaid and laid eggs shows no significant difference. This suggests that the second mating increases the oviposition rate, but not the egg maturation rate in female C. maculatus . Thus, ejaculate serves as a stimulus for oviposition, at least on the remating day. However, because doubly-mated females lay more eggs in total than singly-mated females, doubly-mated females appear to mature more eggs than the singly-mated counterparts. This is attributed to the 'indirect-driven' hypothesis, which states that the reduction in the number of mature eggs in the oviducts brought about by oviposition stimulates the maturation of oocytes in ovarioles to replenish the number of mature eggs.     

Resistance of legume seeds to the bruchid, Callosobruchus maculatus: metabolites relationship

A study was initiated to categorize the seeds of various wild and cultivar legume varieties on the basis of their relative resistance to the bruchid, C. maculatus, and to correlate the important primary and secondary metabolites (non-protein anti-metabolites) in these seeds to the developmental parameters of the bruchid. In general, the wild seed varities showed greater amount of resistance to the bruchid attack when compared to that of the cultivar varieties. All the cultivar varieties studied showed higher amounts of primary metabolites, namely, proteins, carbohydrates, lipids and free amino acids thus showing a positive correlation between the primary metabolites content and the infestation rate. The wild varieties, however, showed significantly lower amounts of these primary metabolites and consequently a lower level of infestation. The non-protein anti-metabolites such as total phenols, ortho- dihydroxy phenols and tannis were significantly lower in the cultivars. The wild varieties, in contrast, revealed higher amounts of these secondary metabolites showing a negative correlation between these secondary metabolites content and the infestation rate. The study revealed that these non-protein anti-metabolites are important in conferring resistance to the seeds.     

Dynamics of genomic change during evolutionary rescue in the seed beetle Callosobruchus maculatus

Rapid adaptation can prevent extinction when populations are exposed to extremely marginal or stressful environments. Factors that affect the likelihood of evolutionary rescue from extinction have been identified, but much less is known about the evolutionary dynamics (e.g., rates and patterns of allele frequency change) and genomic basis of successful rescue, particularly in multicellular organisms. We conducted an evolve‐and‐resequence experiment to investigate the dynamics of evolutionary rescue at the genetic level in the cowpea seed beetle, Callosobruchus maculatus, when it is experimentally shifted to a stressful host plant, lentil. Low survival (~1%) at the onset of the experiment caused population decline. But adaptive evolution quickly rescued the population, with survival rates climbing to 69% by the F5 generation and 90% by the F10 generation. Population genomic data showed that rescue likely was caused by rapid evolutionary change at multiple loci, with many alleles fixing or nearly fixing within five generations of selection on lentil. Selection on these loci was only moderately consistent in time, but parallel evolutionary changes were evident in sublines formed after the lentil line had passed through a bottleneck. By comparing estimates of selection and genomic change on lentil across five independent C. maculatus lines (the new lentil‐adapted line, three long‐established lines and one case of failed evolutionary rescue), we found that adaptation on lentil occurred via somewhat idiosyncratic evolutionary changes. Overall, our results suggest that evolutionary rescue in this system can be caused by very strong selection on multiple loci driving rapid and pronounced genomic change.     

Vibrations mediate prudent resource exploitation by competing larvae of the bruchid bean weevil Callosobruchus maculatus

Larvae of the bean weevil C. maculatus feeding in a single bean apparently respond to vibrations from each other's chewing: one larva feeds normally, the other is inhibited. If the burrows of the larvae intersect, the inhibited larva dies. If the dominant larva pupates or dies without the burrows intersecting, the inhibited larvae then feeds and matures if enough food remains. Since females add second eggs to the largest beans after most beans carry a single egg, competition is most common in the largest available beans, precisely where inhibited larvae can benefit from avoiding a contest.

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Résumé Lors de la compétition, les larves réagissent l'une par rapport à l'autre, même lorsque leurs galeries sont séparées. L'une est inhibée, tandis que l'autre se comporte comme si elle était seule. Le signal provoquant ces réactions, qui peut traverser du papier métallique, est dû vraisemblablement aux vibrations de mastication des larves; ces dernières perçoivent ces signaux tout au long de leur vie active. La larve la plus âgée ne l'emporte pas obligatoirement, ce qui signifie que le signal indique plus que l'âge.Les conditions expérimentales peuvent inverser les réponses des unes et des autres, bien que la larve la plus âgée puisse souvent mourir de ces conditions anormales de compétition. L'avantage potentiel associé à l'inhibition du futur perdant est mis en évidence en collant ensemble des graines. Quand la larve dominante se nymphose, la larve inhibée recommence à s'alimenter et achève son développement. En ayant eu son alimentation interrompue et en restant dans une galerie superficielle, la larve inhibée évite les affrontements et peut se développer lorsque la larve dominante meurt ou se nymphose, puisque la galerie de la larve inhibée n'avait pas été sectionnée.La stratégie de ponte réduit la fréquence de la compétition en uniformisant la distribution des oeufs; elle augmente les chances de survie des larves vaincues avec l'addition des oeufs sur les graines les plus grosses quand les disponibilités sont limitées. L'étude de l'évolution de ces adaptations a été possible puisque, comme on le sait, C. maculatus est génétiquement polymorphe pour les caractères déterminant le comportement de ponte des femelles et la compétition larvaire.

     

Effects of search experience in a resource-heterogeneous environment on the oviposition decisions of the seed beetle, Callosobruchus maculatus (F.)

Abstract.  1. This study investigates how female seed beetles, Callosobruchus maculatus , distribute their eggs on various-sized seeds when the size of seed was varied during the egg-laying period.
2. Beetles were allowed to lay eggs on one of three arrays of 64 adzuki beans ( Vigna angularis ). Each array contained four size classes of seed, ranging from small (5.0–5.5 mm diameter) to large (6.5–7.0 mm), but differed in how they were distributed within the environment. In the most heterogeneous condition (the 64-patch design), the four sizes were interspersed, while in the least heterogeneous condition (the four-patch design) they were grouped into four separate blocks. Thus, a beetle exploring the 64-patch design would frequently encounter all four seed sizes, whereas a beetle exploring the four-patch design would only rarely encounter a change in bean size.
3. Beetles experiencing greater seed size heterogeneity were more likely to lay eggs on larger seeds, whereas those in the blocked condition were more likely to oviposit on small seeds. Beetle responses to seed size heterogeneity suggest that the degree of preference for large seeds depends on a female's recent experience.
4. Female beetles exhibited size discrimination throughout their egg-laying process; however, there was a trade-off between seed size and egg discrimination (i.e. avoiding those seeds already containing developing eggs) in response to the change in fitness gained from either laying on larger seeds or lower egg-load seeds during the egg-laying process.
5. Our model provides the first evidence that evolving seed size discrimination ability is adaptive for the seed beetle with egg-discrimination ability.     

Effect of seed moisture content and d‐limonene on oviposition decisions of the seed beetle Callosobruchus maculatus

Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae) is a cosmopolitan pest of stored pulses and legumes. Under legume storage conditions neither adults nor larvae drink, with larvae obtaining their hydration from metabolic water. However, lack of water limits female fecundity and longevity, thus females might be expected to preferentially oviposit on seeds with high moisture content so as to minimize water stress on their offspring. This was tested by offering females a choice of seeds that differed in relation to their level of water content. After controlling for differences in seed size, females were found to preferentially oviposit on the driest seeds. Offspring size and larval survival were equivalent on seeds that differed in moisture content, which in combination with the preference to lay on the driest seeds would indicate that the egg laying decisions of C. maculatus females do not function to minimize larval water stress. Analysis of the chemical volatiles released by seeds that differed in their moisture content revealed a greater level of d ‐limonene in the environment surrounding high moisture seeds. d ‐limonene has known anti‐herbivory properties, thus we suggest the observed female preference for dry seeds may be related to the observed difference in the level of d ‐limonene in the immediate vicinity of beans that differ with respect to their moisture content.     

Sex allocation and interactions between relatives in the bean beetle, Callosobruchus maculatus

When a small number of females contribute offspring to a discrete mating group, sex allocation (Local Mate Competition: LMC) theory predicts that females should bias their offspring sex ratio towards daughters, which avoids the fitness costs of their sons competing with each other. Conversely, when a large number of females contribute offspring to a patch, they are expected to invest equally in sons and daughters. Furthermore, sex ratios of species that regularly experience variable foundress numbers are closer to those predicted by LMC theory than species that encounter less variable foundress number scenarios. Due to their patterns of resource use, female Callosobruchus maculatus are likely to experience a broad range of foundress number scenarios. We carried out three experiments to test whether female C. maculatus adjust their sex ratios in response to foundress number and two other indicators of LMC: ovipositing on pre-parasitised patches and ovipositing with sisters. We did not find any evidence of the predicted sex ratio adjustment, but we did find evidence of kin biased behaviour.     

Larval competition within seeds: From the behaviour process to the ecological outcome in the seed beetle Callosobruchus maculatus

Abstract Environmental conditions experienced by organisms during development can have profound impacts on adult fitness and behaviour. Internally feeding larvae unable to leave the seed selected by their mother face limitations of resource suitability and competition. The host seed may guide the larval behaviour within the seed leading to differential intensity of competition and determining its process and outcome, which varies in strains of the legume seed beetle Callosobruchus maculatus (Coleoptera: Bruchidae). However, the intensity, process and outcome of larval competition in different hosts have yet to be simultaneously considered, the objective of the present study. Here we assessed the intensity, process and outcome of intrastrain larval competition as related to host type, and how they are interrelated. Larval competition was faced with two distinct strategies – scramble and contest competition depending on the insect strain and host seed species. The intensity of competition did not show any straight link with the process and outcome of competition. Only a single strain showed a contest competition process with likely interference between larvae, while the four other strains studied showed the process of scramble competition. The process of scramble competition, however, led to variable outcomes in mung beans based on larval competition curves. Such differences were not apparent on cowpea seeds and either the plateau or the peak expected on the larval fitness curves were not reached preventing the distinction of the competition outcome, a likely consequence of the egg laying behaviour of these strains limiting the maximum number of eggs laid per seed. Seed host species rather than seed size are the likely cause of the differences observed from the initial expectation. The strain showing the process of contest competition increased larval fitness with density of larvae emerged per seed regardless of the host species, an unexpected outcome based on theoretical models. In this case the egg laying behaviour of the adult female is probably the main fitness determinant of its progeny.     

Oviposition substrate affects adult mortality, independent of reproduction, in the seed beetle Callosobruchus maculatus

Abstract.

• 1 Seed beetles (Coleoptera: Bruchidae) are commonly used to study the influence of reproduction on life-span and senescence. To study the physiological trade-off between reproduction and mortality, many experiments rely on manipulating access to oviposition substrates to manipulate the reproductive rate of females.
• 2 The presence of host seeds, independent of reproduction, results in increased mortality of female Cullosobruchus muculutus. This influence on mortality varies between two host seed species, suggesting a role of either allelochemicals or energetic costs associated with behaviour on hosts.
• 3 The influence of host seeds on survivorship, independent of reproduction, confounds the interpretation of cost-of-reproduction studies with seed beetles. This complication must thus be considered in the design and interpretation of life-history studies of seed beetles and other insects.

     

Differences in midgut serine proteinases from larvae of the bruchid beetles Callosobruchus maculatus and Zabrotes subfasciatus

Proteinase activities in the larval midguts of the bruchids Callosobruchus maculatus and Zabrotes subfasciatus were investigated. Both midgut homogenates showed a slightly acidic to neutral pH optima for the hydrolysis of fluorogenic substrates. Proteolysis of epsilon-aminocaproil-Leu-Cys(SBzl)-MCA was totally inhibited by the cysteine proteinase inhibitors E-64 and leupeptin, and was activated by 1.5 mM DTT in both insects, while hydrolysis of the substrate Z-ArgArg-MCA was inhibited by aprotinin and E-64, which suggests that it is being hydrolysed by serine and cysteine proteinases. Gel assays showed that the proteolytic activity in larval midgut of C. maculatus was due to five major cysteine proteinases. However, based on the pattern of E-64 and aprotinin inhibition, proteolytic activity in larval midgut of Z. subfasciatus was not due only to cysteine proteinases. Fractionation of the larval midgut homogenates of both bruchids through ion-exchange chromatography (DEAE-Sepharose) revealed two peaks of activity against Z-ArgArg-MCA for both bruchid species. The fractions from C. maculatus have characteristics of cysteine proteinases, while Z. subfasciatus has one non-retained peak of activity containing cysteine proteinases and another eluted in a gradient of 250-350 mM NaCl. The proteolytic activity of the retained peak is higher at pH 8.8 than at pH 6.0 and corresponds with a single peak that is active against N-p-tosyl-GlyGlyArg-MCA, and sensitive to 250 microM aprotinin (90% inhibition). The peak contains a serine proteinase which hydrolyzes alpha-amylase inhibitor 1 from the common bean (Phaseolus vulgaris). Arch.     

Environment-dependent reversal of a life history trade-off in the seed beetle Callosobruchus maculatus

Environmental manipulations have consistently demonstrated a cost of reproduction in the capital-breeding seed beetle, Callosobruchus maculatus, as females deprived of seeds or mates lay fewer eggs and thereby increase their longevity. Yet fecundity and longevity tend to be positively correlated within populations, perhaps as a consequence of individual differences in resource acquisition. We conducted a split-brood experiment that combined a manipulation of seed availability (seeds present or absent) with a quantitative-genetic analysis of fecundity and lifespan in each environment. Each trait was significantly heritable in each environment. Seed availability not only altered mean fecundity and longevity between environments, but also modified how the traits were correlated within environments. The signs of both the phenotypic and genetic correlations switched from positive when seeds were present to negative when seeds were absent. This reversal persisted even after the effect of body mass (a potential indicator of resource acquisition) was statistically controlled. Cross-environment genetic correlations were positive but significantly less than one for each trait. We suggest that the reversal of the fecundity-longevity relationship depends on a shift in the relative importance of resource-acquisition and resource-allocation loci between environments. In particular, a cost of reproduction may be apparent at the individual level only when seeds are scarce or absent because differences in reproductive effort become large enough to overwhelm differences in resource acquisition. Despite their common dependence on resources acquired during larval stages, fecundity and lifespan in C. maculatus do not appear to be tightly coupled in a physiological or genetic sense.     

The fecundity and oviposition behavior of a South Indian strain of Callosobruchus maculatus

The fecundity of the South India strain of Callosobruchus maculatus (Fab.) (Bruchidae: Coleoptera) is 73 eggs for females developing in 31 days and increases to 94 eggs for females emerging after 41 days. Fed females lay 45–55 more eggs which is the egg-equivalent of the reserves unfed females had to sacrifice for activity. Competition as a larva did not reduce a female's fecundity. Oviposition is inhibited when females are given 25 or fewer beans for oviposition and it is reversed if females find fresh beans. Oviposition is generally released by beans carrying a below average number of eggs, thus, the eggs are almost uniformly distributed over the beans. Eggs are preferentially placed on the largest egg-free beans as expected if oviposition is released when a beetle goes from a smaller to a larger bean. The cues resulating host preferences, cowpea > mung pigeonpea chickpea, are secondary to the cues producing hyperdispersion and the selection of larger beans. We present a model for the oviposition behavior that accounts for the observed responses to species, size, and egg load of oviposition sites.

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Résumé La fécondité de femelles isolées avec un mâle, sans aliment ni eau, et laissées sans perturbation avec 50 graines au moins sert de fécondité standard. Elle augmente avec le temps de développement de l'uf à l'adulte de 73 ufs (32 j) à 94 ufs (44 j). La fécondité potentielle, obtenue avec des femelles alimentées sur sucre est de 125 ufs. Des femelles maintenues avec moins de 25 graines réduisent leur fécondité.Plus de la moitié des femelles distribuent leurs ufs uniformément jusqu'à une densité de 1,5 uf. L'uniformité peut provenir de l'induction de réactions de ponte par les graines portant moins d'ufs que l'effectif moyen. L'hyperdistribution au dessus des densités de 3 ufs/graine révèle l'aptitude à distinguer les graines avec 3 ufs des graines avec 4 ufs. Il y a moins d'écarts par rapport à l'uniformité (erreurs) avec des graines à surface rugueuse. Des femelles avec 10 graines font moins d'erreurs que des femelles avec 50 ou 100 graines.Les ufs sont ajoutés aux plus grosses graines sans ufs; ainsi, plus il y a de graines qui portent des ufs, plus le poids des graines avec ufs diminue. Un tel schéma est prévisible si la ponte est induite par des graines plus grosses que les graines rencontrées précédemment. Les femelles présentent un ordre de préférence clair quand elles sont en rapport avec leurs hôtes classiques: Vigna unguiculata > V. radiata > Cajanus cajan > Cicer arietinum Les caractères spécifiques de l'hôte, plutôt que la taille ou la texture de la surface servent à la distinction entre les graines d'un même hôte.Ces résultats expérimentaux peuvent être utilisés pour la modélisation du comportement de ponte d'une femelle.

     

Evaluation of different botanical for the management of cowpea bruchid (Callosobruchus maculatus) in north-eastern Ethiopia

The pesticide efficacy of locally available seven botanicals “Gime” (Chenopodium ambrosioides), “Ayderke” (Jatropha curcas), Neem (Azadirachta indica), Melia (Melia azadirach), “Chobe” (Cisus rotonifolia), “Kelewa” (Maesa lanceolata) and “Antharfa” at a rate of 4% weight by weight was evaluated for the control of cowpea bruchid using 200?g cowpea seeds in 500?cm³ volume jar in 2010 and 2011 under laboratory condition at Sirinka Agricultural Research Centre. The combined analysis showed that “Gime” (both leaf and seed) had high speed of pesticide effect as it showed significantly higher per cent of parent adult mortality (84 and 71%, respectively) as to the standard check Malathion 5% dust (100%) in the first day of adult mortality count. “Antharfa” and “Ayderke” also have shown significantly higher per cent of parent adult mortality as to Malathion in the third and fifth day of adult mortality count, respectively. In the seventh day, all botanicals showed significantly higher per cent of adult mortality as compared to untreated check. “Gime” leaf and seed powder, “Ayderke” seed, Neem seed and “Antharfa” leaf powders significantly reduced the number of progeny emergence per day as compared to all other treatments. Moreover, these botanicals were effective in reducing per cent seed damage (0.00, 0.00, 0.57, 5.86 and 10.86%, respectively) and storage loss (0.00, 0.00, 0.073, 1.02 and 2.27%, respectively). Gime (both leaf and seed powder), “Ayderke” seed and Neem seed are locally available, simple for preparation and environmentally friendly. Therefore, these three botanicals can be recommended to satisfy the demand for organic food and save the seed damage and yield loss of cowpea caused by Callosobruchus maculates and bean bruchid (Zabrotes subfasciatus) which has similar biology with Callosobruchus maculatus.