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Simple Summary: This research reveals the efficacy of five plant extracts (Nicotiana tabacum, Nicotiana rustica, Azadirachta indica, Thuja orientalis, and Melia azedarach) against Callosobruchus maculatus. The extracts were tested at six different concentrations with four replications. Phytochemical analysis revealed varying amounts of alkaloids, flavonoids, saponins, diterpenes, phytosterols, and phenols. Among the plants, A. indica showed the highest effectiveness, with the lowest infestation rate (16.65%), seed weight loss (7.85%), mean oviposition (84.54), and adult emergence (58.40%). Conversely, T. orientalis was the least effective. Toxicity analysis using probit analysis indicated that N. tabacum, N. rustica, and A. indica had the highest toxicity, as demonstrated by the lowest LC50 and LC90 values. Repellency tests showed that A. indica exhibited 100.00% highest repellency at a 3% concentration after 48 h against C. maculatus. This study suggests incorporating these plant extracts, especially N. rustica, N. tabacum, A. indica, and M. azedarach, into integrated pest management programs, to manage C. maculatus. An estimated 2000 plant species have been employed for pest control worldwide. The use of these botanical derivatives is thought to be one of the most cost-effective and sustainable options for pest management in stored grain. The present study was designed to assess the efficacy of five plant extracts viz; Nicotiana tabacum L., Nicotiana rustica L., Azadirachta indica A. Juss., Thuja orientalis L., and Melia azedarach L. against Callosobruchus maculatus L. Plant species extracts were applied at six different concentrations, i.e., 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0% in four replications. The phytochemical analyses of ethanolic extracts of five plant species showed variable amounts of phytochemicals i.e., alkaloids, flavonoids, saponins, diterpenes, phytosterol, and phenols. Total phenolic and flavonoid compounds were also observed. The efficacy of A. indica was highest, characterized by the lowest infestation rate (16.65%), host seed weight loss (7.85%), mean oviposition (84.54), and adult emergence (58.40%). In contrast, T. orientalis was found to be the least effective against C. maculatus, with the highest infestation rate of 25.60%, host seed weight loss of 26.73%, mean oviposition of 117.17, and adult emergence rate of 82.01%. Probit analysis was performed by estimating LC50 and LC90. The toxicity percentages of N. tabacum (LC50 = 0.69%, LC90 = 14.59%), N. rustica (LC50 = 0.98%, LC90 = 22.06%), and A. indica (LC50 = 1.09%, LC90 = 68.52%) were notable in terms of the lower LC50 and LC90 values after the 96-h exposure period against C. maculatus. Repellency was assessed by using the area preference and filter paper method. The repellency of C. maculatus on plant extracts increased with the increasing dose and time, such that it was the highest after 48 h. Likewise, at a 3% concentration, A. indica demonstrated 100.00% (Class-V) repellency followed by N. tabacum (96.00%, Class-V), N. rustica (74%, Class-IV), M. azedarach (70.00%, Class-IV), and T. orientalis (68.00%, Class-IV). Based on the findings of this study, we recommend integrating N. rustica, N. tabacum, A. indica, and M. azedarach for effective management of C. maculatus and highlight the potential of these plant species in the formulation of new biocidal agents. [ABSTRACT FROM AUTHOR]

An estimated 2000 plant species have been employed for pest control worldwide. The use of these botanical derivatives is thought to be one of the most cost-effective and sustainable options for pest management in stored grain. The present study was designed to assess the efficacy of five plant extracts viz; Nicotiana tabacum L., Nicotiana rustica L., Azadirachta indica A. Juss., Thuja orientalis L., and Melia azedarach L. against Callosobruchus maculatus L. Plant species extracts were applied at six different concentrations, i.e., 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0% in four replications. The phytochemical analyses of ethanolic extracts of five plant species showed variable amounts of phytochemicals i.e., alkaloids, flavonoids, saponins, diterpenes, phytosterol, and phenols. Total phenolic and flavonoid compounds were also observed. The efficacy of A. indica was highest, characterized by the lowest infestation rate (16.65%), host seed weight loss (7.85%), mean oviposition (84.54), and adult emergence (58.40%). In contrast, T. orientalis was found to be the least effective against C. maculatus, with the highest infestation rate of 25.60%, host seed weight loss of 26.73%, mean oviposition of 117.17, and adult emergence rate of 82.01%. Probit analysis was performed by estimating LC50 and LC90. The toxicity percentages of N. tabacum (LC50 = 0.69%, LC90 = 14.59%), N. rustica (LC50 = 0.98%, LC90 = 22.06%), and A. indica (LC50 = 1.09%, LC90 = 68.52%) were notable in terms of the lower LC50 and LC90 values after the 96-h exposure period against C. maculatus. Repellency was assessed by using the area preference and filter paper method. The repellency of C. maculatus on plant extracts increased with the increasing dose and time, such that it was the highest after 48 h. Likewise, at a 3% concentration, A. indica demonstrated 100.00% (Class-V) repellency followed by N. tabacum (96.00%, Class-V), N. rustica (74%, Class-IV), M. azedarach (70.00%, Class-IV), and T. orientalis (68.00%, Class-IV). Based on the findings of this study, we recommend integrating N. rustica, N. tabacum, A. indica, and M. azedarach for effective management of C. maculatus and highlight the potential of these plant species in the formulation of new biocidal agents.

The broad bean weevil, Bruchus rufimanus Boh. (Coleoptera: Chrysomelidae), also called bruchid beetle, is a major pest of Vicia faba L. (Fabaceae) given that larvae develop inside the seeds causing direct quality losses in agricultural products. Recurrent chemical applications are inappropriate because they represent a serious threat to pollinators in general. In addition, biological control approaches that have been attempted so far showed limited effectiveness, which makes studies of methods to control bruchid populations extremely important. Breeding resistant cultivars is the most adequate approach to achieve efficient levels of pest resistance and promote sustainable agriculture. To explore the mechanisms underlying bruchid resistance, we explored B. rufimanus behavior at different life stages and preference in plant feeding, oviposition, and larval survival into adulthood on a range of susceptible and resistant broad bean cultivars (genotypes), both in greenhouse experiments and in the field. Our greenhouse results showed that females, compared to males, prefer flowers from some genotypes over others, although the choices made did not correspond with egg‐laying preference. Egg‐laying preference was also affected by cultivars. This attraction for egg‐laying was associated with the number of seeds per pod produced by the genotypes. In the field flowering date influenced bruchid infestation. Also the survival of larvae into adulthood was greater in certain genotypes over others. The results of our study lay the groundwork for further analyses to finely dissect V. faba resistance towards bruchids and pave the way for the development of methods to predict potential resistant genotypes in research and breeding programs. [ABSTRACT FROM AUTHOR]

The dried bean beetle, Acanthoscelides obtectus, is an economically important, worldwide pest of legume crops including dry beans, Phaseolus vulgaris. Assessment of A. obtectus infestation levels in pre-harvest field crops and post-harvest granaries is difficult to achieve because there is no effective monitoring tool for early detection so that interventions can be deployed as needed. Because A. obtectus is a generic pollen and nectar feeder, we adopted an electrophysiological (EAG) screening approach, using the antennae of female A. obtectus to identify physiologically active, volatile phytochemicals, which could then be investigated for their attractiveness to A. obtectus in laboratory behavioral assays and preliminary field tests. Of the 27 compounds tested in EAG screening, 5 compounds, i.e., methyl anthranilate, methyl eugenol, benzyl alcohol, (RS)-lavandulol, and 2-phenylethanol, elicited stronger EAG responses than the standard (1-phenylethanol). In 4-arm olfactometer bioassays, female A. obtectus preferred the olfactometer arm containing the odor of either methyl anthranilate or benzyl alcohol compared to the solvent control. In preliminary field tests using these 2 compounds as a binary mixture, at least 5 times as many beetles were caught on baited traps compared to non-baited traps. The field data also suggested that benzyl alcohol was primarily responsible for the field activity of the blend. We hypothesize that the attraction of A. obtectus to the combined benzyl alcohol/methyl anthranilate and the single benzyl alcohol baits is connected to the species' nectar- and pollen-feeding behaviour and not to its intraspecific communication. To our knowledge, this is the first evidence that A. obtectus behavior in the field can be modified by the deployment of plant-derived semiochemicals. [ABSTRACT FROM AUTHOR]

Plant based insecticides are considered among the most economic and ecofriendly chemicals for the protection of plants and stored grains. The cowpea weevil (Callosbruchus maculatus) causes more than 90% damage to sored grains in three to six months. The current study investigates insecticidal potentials of five selected botanicals: Melia azedarach, Nicotiana rustica, Azadirachta indica, Nicotiana tabacum and Thuja orientalis. They are explored at six different concentrations (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0%) against C. maculatus and compared to effects of distilled water which is used as a control. Toxicities of 3%(V/V) extracts of N. tabacum, N. rustica, A. indica and T. orientalis against C. maculatus were 100%, 86.11%, 80.56% and 72.22%, respectively. Maximum mortality was caused by N. tabacum and N. rustica (100%), followed by A. indica (82%), whereas minimum mortality was observed in T. orientalis (64%) at 2.5%. Several phytochemicals, alkaloids, saponins, diterphenes, phytosterol, flavonoids and phenols were identified in N. tabacum and N. rustica, while few were present in A. indica. Phytosterol was present in greatest abundance. Saponins were only detected in aqueous extracts of N. rustica and N. tabacum. Taken together, these results indicate the utility of N. tabacum, N. rustica and A. indica as potential botanicals to control pest beetle and cowpea weevil.

Purple prairie clover (Dalea purpurea Vent.) is a perennial legume native to prairies throughout the central USA and Canada. Seed set in natural populations can be very low, and the reasons are not well known. Our objectives were: 1) describe the reproductive morphology in natural populations of purple prairie clover, 2) identify seed predators and parasitoids associated with natural populations, and 3) determine seed set in natural and cultivated populations of purple prairie clover in eastern SD. Inflorescences were collected from natural and cultivated populations on the South Dakota State University Oak Lake Field Station (OLFS), a cultivated population near Aurora, SD, and from a cultivated population in McCrory Gardens at Brookings, SD. In natural populations at OLFS, normal seed set was ca. 10%, frequency of unfertilized ovules was ca. 20%, and seed predation was ca. 15%. The most easily verifiable seed predator was Acanthoscelides seminulum (Horn). However, the most common insects on the spikes were adults of Kissingeria capitone (Kissinger) and larvae of an unidentified gall midge of genus Contarinia (Cecidomyiidae). The overwhelmingly most common seed predators in the cultivated populations were K. capitone and Contarinia sp. The most common parasitoid reared from beetle larvae was Eurydinoteloides incerta (Ashmead). The chalcidoid wasps Baryscapus sp. and Aprostocetus marylandensis (Girault) parasitized gall midge larvae, with Baryscapus sp. the most abundant by far. In addition, a few individuals of Bracon sp. and Inostemma sp., hosts unknown, were collected from immature inflorescences. Normal seed set in the McCrory Gardens population was 55% compared with <15% in the other cultivated populations. This study identified a previously unknown guild of insects associated with inflorescences in purple prairie clover and revealed probable reasons for a paucity of viable seed production in natural and cultivated populations. [ABSTRACT FROM AUTHOR]

Groundplum milk-vetch (Astragalus crassicarpus Nutt.) is a native legume found on gravelly to sandy prairie uplands throughout central North America. The large and fleshy fruits, or pods, of this species were consumed by indigenous people and European settlers, and are cached by rodents. Our previous research on native legumes of the northern Great Plains indicated seed predation by insects, notably bruchid beetles belonging to the genus Acanthoscelides Schilsky, was a dominant factor determining viable seed production in natural and artificial plant assemblages. However, although we have studied the reproductive biology of several species of Astragalus L., none had fleshy pods. Therefore, the objective of this study was to quantify the factors influencing viable seed production in natural populations of GPMV in South Dakota. Mature pods were collected from two natural populations on the South Dakota State University Oak Lake Field Station during July 2000 and from one natural population on the Grand River National Grassland near Lodgepole, SD, in July 2003. Pods were dissected and number of ovules that: 1) produced viable seed, 2) were unfertilized, 3) produced aborted seed, and 4) produced seeds that were predated by larvae of the bruchid beetle Acanthoscelides fraterculus (Horn) (Coleoptera: Chrysomelidae: Bruchinae) were recorded for each of the two valves of individual pods. Our results indicated average seed set, i.e., percent of ovules that produced viable seed not predated, was about 55%, averaged across populations. Unfertilized ovules were 42% of the total. Predation by the bruchid beetle occurred in about 2% of the developed seeds, with aborted seed making up the rest of the ovule total. About 35% of pods infested contained larvae, or adults that were immured within the pod while attempting to exit, presumably due to the thick and leathery layers of the ovary wall. Predispersal seed predation was a relatively minor factor in the reduction of viable seed set in GPMV in South Dakota. [ABSTRACT FROM AUTHOR]

During storage groundnut is attacked by number of stored grain pest and management of these insect pests particularly bruchid beetle, Caryedon serratus (Oliver) is of prime importance as they directly damage the pod and kernels. Hence, some essential oils were tested for their insecticidal and fungicidal properties. Highest total bruchid mortality was recorded with the application of neem oil and pongamia oil at 10% (v/w) concentration and lowest in eucalyptus oil at 5% (v/w). Number of eggs laid was recorded 2.3 in neem oil 10% (v/w) which was lowest and significantly superior over untreated control and was at par with castor oil 10% (v/w) which recorded 2.5 eggs per 100 g of groundnut pods. There was no adult emergence in the groundnut pods treated with castor oil, eucalyptus oil, neem oil and pongamia oil at 10% (v/w) concentration. Groundnut pods treated with castor oil, eucalyptus oil, neem oil and pongamia oil at 10% (v/w) and neem oil at 5% (v/w) concentrations recorded no damage to pods and kernels and also zero per cent weight loss. These oils effectively influenced groundnut bruchid establishment and reduce damage besides reduction in aflatoxin contamination. [ABSTRACT FROM AUTHOR]

Plant based insecticides are considered among the most economic and ecofriendly chemicals for the protection of plants and stored grains. The cowpea weevil ( Callosbruchus maculatus ) causes more than 90% damage to sored grains in three to six months. The current study investigates insecticidal potentials of five selected botanicals: Melia azedarach, Nicotiana rustica, Azadirachta indica , Nicotiana tabacum and Thuja orientalis. They are explored at six different concentrations (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0%) against C. maculatus and compared to effects of distilled water which is used as a control. Toxicities of 3%(V/V) extracts of N. tabacum, N. rustica, A. indica and T. orientalis against C. maculatus were 100%, 86.11%, 80.56% and 72.22%, respectively. Maximum mortality was caused by N. tabacum and N. rustica (100%), followed by A. indica (82%), whereas minimum mortality was observed in T. orientalis (64%) at 2.5%. Several phytochemicals, alkaloids, saponins, diterphenes, phytosterol, flavonoids and phenols were identified in N. tabacum and N. rustica, while few were present in A. indica. Phytosterol was present in greatest abundance. Saponins were only detected in aqueous extracts of N. rustica and N. tabacum. Taken together, these results indicate the utility of N. tabacum , N. rustica and A. indica as potential botanicals to control pest beetle and cowpea weevil.

Despite the often dramatic negative effects of inbreeding on offspring fitness, matings between closely related individuals sometimes occur. This may be because females cannot reliably recognize related males before mating with them. As an alternative to precopulatory choice, polyandrous females may avoid inbreeding through postcopulatory mechanisms if they can assess mate relatedness during or after copulation. These mechanisms include increasing remating propensity and decreasing rate of offspring production in response to incestuous matings. Stored product pests, such as the bruchid beetle Callosobruchus maculatus, have an ecology that is likely to expose them to frequent risks of inbreeding when a small number of females found a new population on a previously uninfested store of beans. Using this species, we show that inbreeding has negative effects on offspring viability but that females do not appear to discriminate between brothers and unrelated males prior to mating. Furthermore, females that first mated with brothers did not increase their remating propensity or decrease their rate of offspring production relative to females that first mated with unrelated males. Our findings suggest that the costs of inbreeding have not been sufficient to drive the evolution of mating behaviour as a mechanism of inbreeding avoidance in C. maculatus. [Copyright &y& Elsevier]

Because male uncertainty over parentage limits the value of paternal investment in offspring, mate attraction and facilitation of ejaculate transfer are thought to be important functions of nuptial gifts. However, these are unlikely functions for valuable resources in ejaculates delivered inside the female. Instead, ejaculates containing costly nuptial gifts may be maintained because females alter their mating behaviour in response to the trade-off between the costs and benefits of mating. The value of receiving an additional gift should decrease with improved female physiological condition. Providing a female with a substantial gift will therefore make it less profitable for her to remate and reduce the risk of future sperm competition. Females of the bruchid beetle Callosobruchus maculatus are harmed by the spiny male genitalia during copulation but also appear to derive material benefits from the large ejaculates. I kept female C. maculatus with access to water and other females without access to water. All females were given the opportunity to mate with a new male every day. Females without access to water mated more frequently than females with access to water. I suggest that female C. maculatus mate more frequently to obtain water when dehydrated and that this may select for ejaculates containing large amounts of water in males. By providing their mates with a large amount of water, males can delay female remating and reduce the risk of future sperm competition. [Copyright &y& Elsevier]