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Copyright of Research in Agricultural Sciences is the property of Ataturk University Coordinatorship of Scientific Journals and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Morphological plasticity may be induced by altering host plants and commonly it is sex‐specific in phytophagous insects. It is hypothesized that stress in insects caused by a host shift leads to morphological changes and developmental destabilization, which may be identified by fluctuating asymmetry. We performed reciprocal transplant experiments in eight replicated populations of the seed beetle Acanthoscelides obtectus (Say) (Coleoptera: Chrysomelidae, Bruchinae) adapted to common bean (Phaseolus vulgaris L., Fabaceae) as its ancestral host and chickpea (Cicer arietinum L., Fabaceae) as a suboptimal host. Using methods of geometric morphometrics we assessed the effects of the short‐ and long‐term host shift on size and shape variation of beetles of both sexes. We also tested the hypothesis that fluctuating asymmetry is lower when the beetles develop within seeds of the ancestral host. Our results showed that females respond more plastically related to their body size and shape of the abdomen, particularly during a short‐term host shift, suggesting that females have a greater importance in maintaining the population on a new host. The level of fluctuating asymmetry is lowest in males that have evolved for generations on bean indicating that they have the most canalized development, so we suggested that symmetry in A. obtectus is maintained by sexual selection. Even if the beetles are adapted to a suboptimal host over many generations, they stabilize their development after returning to the ancestral host. Our work indicates that host shifts may change morphological aspects of the beetles in a sex‐specific manner and consequently influence their developmental trajectories. [ABSTRACT FROM AUTHOR]

One method of crop protection is the application of a widely used group of pesticides—pyrethroids. As xenobiotics, sub-lethal doses of insecticides cause stress in pests, resulting in a change in the shape and size of their organs or bodies. The stress caused by pesticides may lead to acute destabilization of development, but also to transgenerational canalization through the process of genetic assimilation. Fluctuating asymmetry (FA), small random deviations between the right and left sides of bilaterally symmetrical traits, is an outcome of developmental instability and is a measurable indicator of phenotypic response to stress. We exposed four populations of the seed beetle Acanthoscelides obtectus to sub-lethal doses of cypermethrin for ten generations in a laboratory evolution experiment. Using geometric morphometrics, we analyzed size and shape changes and the level of fluctuating asymmetry in untreated beetles and in samples from the fifth and tenth generation. Exposure over ten generations led to an increase in the body size of the beetles, shortening of their pronotum and elongation of their thorax and abdomen. After ten generations of exposure to cypermethrin, FA levels decreased, indicating a canalization of development. This study provides new insights into the phenotypic markers of environmental pollution from agricultural activities. [ABSTRACT FROM AUTHOR]

Bu çalışmanın amacı depolanmış ürün zararlısı olan Acanthoscelides obtectus Say (Coleoptera: Chrysomelidae) ile mücadelede kimyasal kullanımının azaltılmasına alternatif olarak 3A, 4A ve 5A zeolitleri kullanarak zararlı popülasyonunu ekonomik zarar eşiğinin altına düşürmektir. Ülkemizde ve dünyada depo zararlılarıyla mücadelede kalıntı bırakmayan uygulamaların geliştirilmesi ve özellikle baklagillerin muhafaza edilmesinde kullanılan zeolit minerallerini de içeren inert tozların kullanımı önem arz etmektedir. İnert tozlar içinde yer alan zeolit, depolanmış tahıllarda ürüne karıştırılarak zararlılara karşı uzun süreli koruma sağlamaktadır. Sentetik zeolitlerin adsorplama, katalizör olma ve iyon değiştirici özelliklerine göre kullanım alanları oldukça geniştir. Bu amaçla A. obtectus’a karşı 3A, 4A ve 5A zeolitler 27 ± 2°C, %65 ± 5 bağıl nem sabit koşulları altında ısıtmalı/soğutmalı inkübatör içerisinde beş farklı dozda (25mg, 50 mg, 75 mg, 100 mg ve 125 mg) test edilmiştir. Uygulama beş tekerrürlü ve her tekerrürde 20 adet ergin olacak şekilde yapılmıştır. Yüzde ölüm oranlarını hesaplamak amacıyla 1, 3, 6, 12, 24, 48, 72, 96, 120 ve 144. saat aralıklarla kontroller yapılmış, canlı ve ölü ergin sayıları kaydedilmiştir. Uygulama öncesi ve sonrası ağırlık kayıpları da değerlendirilmiştir. Çalışma sonucunda, zeolitlerin hepsinin kontrole göre etkili sonuçlar verdiği, ancak ayrı ayrı incelendiğinde 3A ve 5A zeolitlerin 4A zeolite kıyasla A. obtectus’a karşı daha etkili oldukları belirlenmiştir. 3A ve 5A zeolitler için istatistiki olarak en yüksek ölüm oranının 125 mg dozda 72. saatte, 4A zeolit için 125 mg dozda 96. saatte olduğu kaydedilmiştir. Tüm dozlar için %100 ölümler 96-144. saatlerde tamamlanmıştır. 3A, 4A ve 5A zeolit dozlarının ve maruz kalma sürelerinin artması A. obtectus’un ölüm oranını arttırmış, yumurta sayısını düşürmüş ve dolayısıyla F1 nesli üretiminde azalmaya sebep olmuştur. Elde edilen sonuçlara göre 3A, 4A ve 5A zeolitlerin A. obtectus’un mücadelesi için umut verici olduğu sonucuna varılmıştır.

One method of crop protection is the application of a widely used group of pesticides—pyrethroids. As xenobiotics, sub-lethal doses of insecticides cause stress in pests, resulting in a change in the shape and size of their organs or bodies. The stress caused by pesticides may lead to acute destabilization of development, but also to transgenerational canalization through the process of genetic assimilation. Fluctuating asymmetry (FA), small random deviations between the right and left sides of bilaterally symmetrical traits, is an outcome of developmental instability and is a measurable indicator of phenotypic response to stress. We exposed four populations of the seed beetle Acanthoscelides obtectus to sub-lethal doses of cypermethrin for ten generations in a laboratory evolution experiment. Using geometric morphometrics, we analyzed size and shape changes and the level of fluctuating asymmetry in untreated beetles and in samples from the fifth and tenth generation. Exposure over ten generations led to an increase in the body size of the beetles, shortening of their pronotum and elongation of their thorax and abdomen. After ten generations of exposure to cypermethrin, FA levels decreased, indicating a canalization of development. This study provides new insights into the phenotypic markers of environmental pollution from agricultural activities.

Copyright of Harran Journal of Agricultural & Food Science is the property of Harran University, Faculty of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT The common bean weevil (Acanthoscellides obtectus [Say]) is a major post‐harvest pest of common bean (Phaseolus vulgaris L.) in tropical regions. Developing and using weevil‐resistant varieties is the most environmentally and cost‐effective means of mitigating the losses caused by the common bean weevil. The arcelin–phytohemagglutinin–alpha‐amylase (APA) locus, originally from tepary bean (Phaseolus acutifolius A. Gray), provides effective resistance against the common bean weevil. The APA locus is currently deployed in very limited market classes, and knowledge of the stability of its resistance across different market classes of common bean is limited. The objectives of this study were to (i) introgress the APA locus into selected market classes of Andean gene pool of common bean and (ii) determine the stability of APA‐based resistance to A. obtectus (AO) in multiple market classes of common bean. A total of 571 F5:7 breeding lines derived from crossing the weevil‐resistant breeding line AO‐1012‐29‐3‐3A (AO‐3A) possessing the APA locus with seven Andean genotypes belonging to five market classes were evaluated for resistance to AO. Of the 571 breeding lines screened, 16 were resistant, representing a low weevil resistance recovery rate of 2.8%. These lines are across diverse market classes, including those preferred in African countries. Of the 16 newly developed resistant breeding lines, six were more resistant to AO (scores ranging from 1–1.3) than AO‐3A (score of 2), and these can be used for further genetic enhancement of common bean resistance to AO.

During storage, Acanthoscelides obtectus causes deterioration of bean seeds and offers favorable conditions for fungi development. To prevent losses, the application of chemical pesticides is the most effective method, but it can cause both health and environmental problems. Therefore, researchers have developed Plant-based products that could serve as potential alternatives. This study assessed the efficiency of essential oil from Mondia whitei roots (MWEO) in the preservation of bean seeds. This oil was extracted from the roots by hydro-distillation with a yield of 1.5%. Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography-Mass Spectrometry (GC-MS) analysis revealed that MWEO was rich in 2-hydroxy-4-methoxy-benzaldehyde accounting for 81%. The activity of this oil as an insecticide was evaluated both through contact and fumigation toxicity tests. Furthermore, the impact of the tested oil on germination of bean seeds and the inhibition of F1 progeny production of insects were investigated. MWEO exhibited excellent toxicity against adult A. obtectus with Lethal Dose 50 (LD50) of 0.15 µl/cm3 and 0.80 µl/g by fumigation and contact bioassay respectively. Compared to the control, MWEO significantly reduced F1 adult emergence and grain weight loss. However, it shows adverse effects on germination capability of seeds 3 months after treatment. The antifungal activity was assessed on some fungi strains previously isolated on bean seeds. Amongst the fungi tested, Aspergillus niger was the most susceptible with Minimum Inhibitory Concentration of 0.06 mg/ml. Our findings suggest that MWEO has a promising antifungal and insecticidal activities, and can therefore be used as a natural alternative and/or complementary to chemical pesticides. [ABSTRACT FROM AUTHOR]

Expansion of the host range in phytophagous insects, followed by the specialisation on novel hosts, encompasses changes in many aspects of insects' behaviour, physiology, and the interaction between their life‐history features.Here, we analyse the roles of insects' developmental plasticity in the process of host shift. Using laboratory populations of the seed beetle (Acanthoscelides obtectus), which have evolved on both optimal (common beans) and suboptimal (chickpea) plant hosts for more than 35 years, we experimentally replicated the process of host shift and analysed the patterns of short‐term and long‐term life‐history responses to host variation.In order to test whether selection for increased plasticity has an effect on host shifting processes, we used existing bean and chickpea adapted populations to establish new populations in which the host plant offered for insect development was changed each generation (for 13 generations). To test the potential for a short‐term plastic response, beetles from each laboratory population were raised on both hosts for one generation.Results showed that, in contrast to the populations that evolved on beans, which maintained high levels of developmental plasticity, long‐term host switching to chickpeas was accompanied with specialisation of pre‐adult viability with a simultaneous increase in fecundity. Populations evolved on alternate plant hosts that revealed similar plasticity patterns as their ancestral populations.These results suggest that short‐term plastic responses could determine the paths of long‐term evolution of life‐history plasticity. However, more time could be needed for plasticity to evolve differently from the initial responses. [ABSTRACT FROM AUTHOR]

Abstract Background Common bean (Phaseolus vulgaris L.) is an important agricultural product with large nutritional value, and the insect pest Acanthoscelides obtectus (Say) seriously affects its product quality and commodity quality during storage. Few researches on genes of bruchid resistance have investigated in common bean cultivars. Results In this study, a bruchid-resistant cultivar black kidney bean and a highly susceptible accession Longyundou3 from different gene banks were crossed to construct a recombinant inbred line population. The genetic analysis indicated a quantitative inheritance of the bruchid resistance trait controlled by polygenes. A high-density genetic map of a total map distance of 1283.68 cM with an average interval of 0.61 cM between each marker was constructed using an F6 population of 157 recombinant inbred lines. The map has 3106 bin markers, containing 2,234,769 SNPs. Using the high-density genetic map, a new quantitative trait locus for the resistance to Acanthoscelides obtectus was identified on chromosome 6. New molecular markers based on the candidate region were developed, and this locus was further delimited to an interval of 122.3 kb between SSR markers I6–4 and I6–16 using an F2 population. This region comprised five genes. Phvul.006G003700, which encodes a bifunctional inhibitor, may be a potential candidate gene for bruchid resistance. Sequencing analysis of candidate gene identified a 5 bp insertion-deletion in promoter of gene Phvul.006G003700 between two parents. Expression analysis of candidate gene revealed that the expression level of Phvul.006G003700 in bruchid-resistant parent was markedly higher than that in bruchid-susceptible parent both in dry seeds and leaves. Conclusions A high-density genetic linkage map was constructed utilizing whole-genome resequencing and one new QTL for bruchid resistance was identified on chromosome 6 in common bean cultivar. Phvul.006G003700 (encoding a bifunctional inhibitor) may be a potential candidate gene. These results may form the basis for further research to reveal the bruchid resistance molecular mechanism of common bean.

Simple Summary: Acanthoscelides obtectus is an insect pest that attacks wild and cultivated common beans (Phaseolus vulgaris L). Four Trichoderma strains, T. arundinaceum IBT 40837, Ta37-17.139 (=Δtri17), and Ta37-23.74 (=Δtri23), and T. brevicompactum IBT 40841 were assessed to establish their direct effect on insect attacks and their indirect effect on the plants grown from the beans treated with those fungal strains and exposed to insect attacks. Treatments of bean seeds with different Trichoderma strains led to different survival rates in the insects. Insect cadavers (in contact with Δtri23) showed growth of this strain. The emergence of insects was reduced in the beans treated with the Ta37, Tb41, and Δtri17 strains. The undamaged beans (treated with Ta37 and Δtri23) provided a high capacity of germination, whereas the Δtri17 and Tb41 treatments increased the capacity of germination in the damaged beans. The undamaged beans treated with Δtri23 obtained the greatest dry weights of the aerial part and root system in the plants. More studies on the mechanisms of insect control, plant growth promotion, and volatile compound production by Δtri23 and Tb41 should be explored in order to commercialize these fungal species on a massive scale. Acanthoscelides obtectus is an insect pest that attacks wild and cultivated common beans (Phaseolus vulgaris L). Four Trichoderma strains, the T. arundinaceum IBT 40837 wild-type strain (=Ta37), a producer of trichothecene harzianum A (HA), two transformants of T. arundinaceum strain, Ta37-17.139 (=Δtri17) and Ta37-23.74 (=Δtri23), and the T. brevicompactum IBT 40841 wild-type strain (=Tb41), which produces the trichothecene trichodermin, were assessed to establish their direct effect on insect attacks and their indirect effect on the plants grown from the beans treated with those fungal strains and exposed to insect attacks. Treatments of bean seeds with different Trichoderma strains led to different survival rates in the insects, and the Tb41 strain caused the lowest survival rate of all. An 86.10% of the insect cadavers (in contact with Δtri23) showed growth of this strain. This was the treatment that attracted the greatest number of insects. The daily emergence was reduced in beans treated with the Ta37, Tb41, and Δtri17 strains. The undamaged beans treated with Ta37 and Δtri23 showed a high capacity of germination (80.00% and 75.00%, respectively), whereas the Δtri17 and Tb41 treatments increased the capacity of germination in the damaged beans (66.67%). The undamaged beans treated with Δtri23 had the greatest dry weights for the aerial part (4.22 g) and root system in the plants (0.62 g). More studies on the mechanisms of insect control, plant growth promotion, and trichodermol and trichodermin production by Δtri23 and Tb41, respectively, should be explored in order to commercialize these fungal species on a large scale. [ABSTRACT FROM AUTHOR]

This study aimed to verify the level of repellent and mortality effect of two chemical substances (DEET and 2-undecanone) and seven essential oils (EOs), Allium sativum, Artemisia annua, Ocimum basilicum, Lavandula angustifolia, Eucalyptus globulus, Pinus sylvestris, and Curcuma longa. The storage pests Tribolium confusum, Tenebrio molitor, and Acanthoscelides obtectus were exposed to various concentrations in an olfactometer-and-mortality test. The effects were recorded 24–48–72 h after the treatments were applied. A. sativum, E. globulus, and L. augustifolia were found to have significant repellence effects. A substantial lethal effect was observed for A. sativum, E. globulus, and O. basilicum. We also found that even if the most efficient EOs were diluted to low concentrations, they still produced repellent and mortality effects. The presented results indicate that A. sativum and O. basilicum were the most effective against T. confusum and T. molitor; simultaneously, L. angustifolia and C. longa showed high activity against A. obtectus. All of these efficient EOs could be applied as effective bio-control agents in various stored conditions. [ABSTRACT FROM AUTHOR]

Acanthoscelides obtectus is one of the most notorious pests of stored kidney beans (Phaseolus vulgaris) worldwide. Kidney beans are an important source of food for these insects. α-Amylase is the main carbohydrate-digesting enzyme in animals including insects. In the current study, the biochemical analysis revealed higher α-amylase activity (U/ml) in 3rd and 4th larval instars but decreased gradually in subsequent developmental stages. However, the specific activity (U/mg) interestingly was highest in 1st instar and decreased in further developmental stages. During qualitative analysis of α-amylase using starch-agar and native PAGE, the maximum zone of starch lysis and a prominent band on the gel was observed in 3rd and 4th larval stages. The molecular mass of the native enzyme was also estimated and found to be 30.34 kDa. The crude α-amylase was further purified by ammonium sulfate precipitation, gel filtration on a Sephadex G-75, and ion exchange chromatography on the DEAE cellulose column. The purified amylase was found to be a monomer with a molecular mass of 15 kDa. The specific activity of the purified enzyme increased from 1.74 U/mg in the crude sample to 166.35 U/mg in the final purification step resulting in 95-fold purification with a yield of 11.14%. Further characterization of purified α-amylase revealed a pH optimum of 7.0 and a temperature optimum of 35 °C. Lineweaver-Burk plot analysis revealed K m and V max to be 0.09% and 3.3 U/mL, respectively. Oxalic acid, tannic acid, and HgCl 2 significantly inhibited the enzyme, while the Na+, Ca++, and Mg++ ions acted as activators. In conclusion, the study revealed, the highest α-amylase activity in 3rd and 4th larval stages of Acanthoscelides obtectus followed by native and SDS PAGE resulting in molecular mass of 30.34 and 15 kDa respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

Acanthoscelides obtectus, which is a pest of stored products, completes its larval development in legumes. It is among economically important species in our country since it reduces the germination value and nutritional value of seeds. As a result of understanding the effects of entomopathogenic fungi on pests in recent years, researchers have also focused on fungi in fighting pests. These fungi, which are sold as bioinsecticides in the market, are generally preferred by producers who want to engage in organic or environmentally sensitive agriculture. Although there are a large number of sources in literature on the mortality rates of Beauveria bassiana's A. obtectus, studies on the effects on the biology of the pest, the number of eggs it lays and the number of adults emerging from beans after the application are limited. In this study, the effects of different concentrations of Beauveria bassiana (Nostalgist BL®) on the mortality rates of A. obtectus adults, the number of eggs they lay and the number and percentages of adults emerging from bean seeds were evaluated with dipping and spraying method. It was found that as the concentration of B. bassiana, which was applied at concentrations of 0.1%, 0.2% and 0.4% increased, the mortality rates on the adults of the pest increased and the number of eggs they laid and the number of adults emerging from bean seeds decreased. It can be said that different doses of B. bassiana are quite effective on the mortality rates of A. obtectus adults, the number of eggs they lay, and especially the number of adults emerged from beans. [ABSTRACT FROM AUTHOR]

Background: Common bean (Phaseolus vulgaris L.) is an important agricultural product with large nutritional value, and the insect pest Acanthoscelides obtectus (Say) seriously affects its product quality and commodity quality during storage. Few researches on genes of bruchid resistance have investigated in common bean cultivars. Results: In this study, a bruchid-resistant cultivar black kidney bean and a highly susceptible accession Longyundou3 from different gene banks were crossed to construct a recombinant inbred line population. The genetic analysis indicated a quantitative inheritance of the bruchid resistance trait controlled by polygenes. A high-density genetic map of a total map distance of 1283.68 cM with an average interval of 0.61 cM between each marker was constructed using an F6 population of 157 recombinant inbred lines. The map has 3106 bin markers, containing 2,234,769 SNPs. Using the high-density genetic map, a new quantitative trait locus for the resistance to Acanthoscelides obtectus was identified on chromosome 6. New molecular markers based on the candidate region were developed, and this locus was further delimited to an interval of 122.3 kb between SSR markers I6–4 and I6–16 using an F2 population. This region comprised five genes. Phvul.006G003700, which encodes a bifunctional inhibitor, may be a potential candidate gene for bruchid resistance. Sequencing analysis of candidate gene identified a 5 bp insertion-deletion in promoter of gene Phvul.006G003700 between two parents. Expression analysis of candidate gene revealed that the expression level of Phvul.006G003700 in bruchid-resistant parent was markedly higher than that in bruchid-susceptible parent both in dry seeds and leaves. Conclusions: A high-density genetic linkage map was constructed utilizing whole-genome resequencing and one new QTL for bruchid resistance was identified on chromosome 6 in common bean cultivar. Phvul.006G003700 (encoding a bifunctional inhibitor) may be a potential candidate gene. These results may form the basis for further research to reveal the bruchid resistance molecular mechanism of common bean. [ABSTRACT FROM AUTHOR]

A review of the literature on the ecology, biology, distribution of bean bruchid (Acanthoscelides obtectus) and its main food plant Phaseolus vulgaris in North and South America, Europe, Africa, Asia, and Australia and in more detail in Russia is presented. The review also considers the influence of abiotic, biotic, and anthropogenic factors on the invasive process and phytosanitary condition of common bean crops in Russia. Some aspects of the management of the invader are shown. The main stages and areas of cultivation of common bean and invasion of bean bruchid from their primary range in South America and in the south of North America are traced; the vectors and reasons causing them are considered. In Russia, the economic importance of bean bruchid has increased since the mid-1980s, which coincided with the climate warming; there was an expansion of its distribution in the eastern and northwestern directions. In the last decades of the 20th century, it penetrated into Smolensk and into the south part of Tver and the Tomsk Regions. With the increase in production of beans in Russia, the lack of systemic protection from bean bruchid and further increase in climate warming will contribute to the extension of its range to the north in the European part of Russia and the Urals to 57°–58° N, where the conditions of the summer period are favorable for development of common bean and bean bruchid. To the east, it may spread to Tyva, Buryatia, Zabaykalsky Territory, Amur Region, the Jewish Autonomous Region, and the southern part of Khabarovsk Territory. With the introduction of strict internal quarantine and a system of protection of common bean from this pest which prevents the spread of infected dry bean, on the contrary, it is possible to reduce the range of distribution of the bean bruchid, with its disappearance in the Siberian and Ural districts and Bashkortostan and Tatarstan. [ABSTRACT FROM AUTHOR]

Acanthoscelides obtectus Say (Coleoptera: Chrysomelidae: Bruchinae), is one of the most important pests of the common bean Phaseolus vulgaris L. Without appropriate management it may cause significant seed loss in storages. In search for means of environmentally safe and effective protection of beans we assessed biological activity of thymol, an oxygenated monoterpene present in essential oils of many aromatic plants. We studied contact toxicity of thymol on bean seeds and its effects on adult longevity and emergence in F1 generation. Furthermore, we determined acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT), mixed-function oxidase (MFO), carboxylesterases (CarE) and glutathione S-transferase (GST) activities in response to 24 h exposure of beetles to sublethal and lethal thymol concentrations. Our results showed that thymol decreased adult survival, longevity and percentage of adult emergence. Higher median lethal concentration (LC50) was recorded in females indicating their higher tolerance comparing to males. Overall, activities of SOD, CAT and CarE increased at sublethal and MFO increased at both sublethal and lethal thymol concentrations. On the other hand, GST and AChE activities decreased along with the increase in thymol concentrations from sublethal (1/5 of LC50, 1/2 of LC50) to lethal (LC50). Enzyme responses to the presence of thymol on bean seed were sex-specific. In the control group females had lower CarE and higher SOD, CAT and GST activity than males. In treatment groups, females had much higher CAT activity and much lower CarE activity than males. Our results contribute to deeper understanding of physiological mechanisms underlying thymol toxicity and tolerance which should be taken into account in future formulation of a thymol-based insecticide. [ABSTRACT FROM AUTHOR]

The bean bruchid, Acanthoscelides obtectus (Say) (Coleoptera: Chrysomelidae), a serious pest of kidney beans, Phaseolus vulgaris L., worldwide. In Rwanda, management of this pest in stored beans is generally based on conventional chemical insecticide applications with high residues. In this study, a pyrethrum-based product (Agrothrin®), a natural extract from the African pyrethrums with no side effects, was evaluated under laboratory and warehouse conditions. In both laboratory and warehouse assays, the product was tested at seven different doses ranging from 0.9 kg/ton to 2.1 kg/ton and compared with an untreated control and a conventional chemical insecticide control (malathion). The results showed that the insecticidal activity of Agrothrin® was low and not quick at lower doses and shorter exposure times, and higher doses ≥ 1.5 kg/ton and longer exposures > 2 weeks were needed to obtain an adult mortality more than 80%. In warehouse assays, the product gave effective bean seed protection against A. obtectus. The pest was predominantly present in positive (mean no. of living and dead beetles: 1.33 and 0.83/5 kg seed) and negative (mean no. of living and dead beetles: 2.50 and 3.33/5 kg seed) controls, but absent or in low number (mean no. of living and dead beetles: generally lower than 0.50/5 kg seed) in bean seeds treated with the product. Overall results suggest that Agrothrin® may be a very effective alternative to the existing conventional chemical insecticides in stored bean protection at doses equal to or higher than 1.7 kg/ton of seeds. [ABSTRACT FROM AUTHOR]

Acanthoscelides obtectus Say (Coleoptera: Chrysomelidae: Bruchinae), is one of the most important pests of the common bean Phaseolus vulgaris L. Without appropriate management it may cause significant seed loss in storages. In search for means of environmentally safe and effective protection of beans we assessed biological activity of thymol, an oxygenated monoterpene present in essential oils of many aromatic plants. We studied contact toxicity of thymol on bean seeds and its effects on adult longevity and emergence in F1 generation. Furthermore, we determined acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT), mixed-function oxidase (MFO), carboxylesterases (CarE) and glutathione S-transferase (GST) activities in response to 24 h exposure of beetles to sublethal and lethal thymol concentrations. Our results showed that thymol decreased adult survival, longevity and percentage of adult emergence. Higher median lethal concentration (LC50) was recorded in females indicating their higher tolerance comparing to males. Overall, activities of SOD, CAT and CarE increased at sublethal and MFO increased at both sublethal and lethal thymol concentrations. On the other hand, GST and AChE activities decreased along with the increase in thymol concentrations from sublethal (1/5 of LC50, 1/2 of LC50) to lethal (LC50). Enzyme responses to the presence of thymol on bean seed were sex-specific. In the control group females had lower CarE and higher SOD, CAT and GST activity than males. In treatment groups, females had much higher CAT activity and much lower CarE activity than males. Our results contribute to deeper understanding of physiological mechanisms underlying thymol toxicity and tolerance which should be taken into account in future formulation of a thymol-based insecticide.

Although increasing focus is being given to the control of insect pests with natural products, the study of volatile mediated microbe-insect interactions has been largely neglected so far. Currently, no standardized method is available for the in vitro evaluation of the effects produced on insects by Volatile Organic Compounds (VOCs) directly emitted by actively growing microbial strains. This manuscript presents a reliable protocol using VOC Chambers (Álvarez-García et al., 2021) to assess these effects and specifically those exerted on dry grain insect pests. The methodology also serves to evaluate the impact of these volatile interactions on the grain damage produced by the insects. It allows to vary the level of gas exchange with the environment, thus providing different experimental conditions to emulate diverse natural ones in which these interactions may occur.Our method adapts the use of VOC Chambers for the evaluation of microbe-insect volatile interactions and the in vitro screening of microbial strains that produce potentially bioactive VOCs against insects.It allows assessing the effects of these volatile interactions on the damage produced by insect pests on stored dry grains.Sealed and unsealed setups can be used to determine the impact of ventilation and gas exchange on these interactions.

Acanthoscelides obtectus is an insect pest that attacks wild and cultivated common beans (Phaseolus vulgaris L). Four Trichoderma strains, the T. arundinaceum IBT 40837 wild-type strain (=Ta37), a producer of trichothecene harzianum A (HA), two transformants of T. arundinaceum strain, Ta37-17.139 (=Δtri17) and Ta37-23.74 (=Δtri23), and the T. brevicompactum IBT 40841 wild-type strain (=Tb41), which produces the trichothecene trichodermin, were assessed to establish their direct effect on insect attacks and their indirect effect on the plants grown from the beans treated with those fungal strains and exposed to insect attacks. Treatments of bean seeds with different Trichoderma strains led to different survival rates in the insects, and the Tb41 strain caused the lowest survival rate of all. An 86.10% of the insect cadavers (in contact with Δtri23) showed growth of this strain. This was the treatment that attracted the greatest number of insects. The daily emergence was reduced in beans treated with the Ta37, Tb41, and Δtri17 strains. The undamaged beans treated with Ta37 and Δtri23 showed a high capacity of germination (80.00% and 75.00%, respectively), whereas the Δtri17 and Tb41 treatments increased the capacity of germination in the damaged beans (66.67%). The undamaged beans treated with Δtri23 had the greatest dry weights for the aerial part (4.22 g) and root system in the plants (0.62 g). More studies on the mechanisms of insect control, plant growth promotion, and trichodermol and trichodermin production by Δtri23 and Tb41, respectively, should be explored in order to commercialize these fungal species on a large scale.

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The bean weevil Acanthoscelides obtectus is one of the major storage pests of dry bean. Tepary bean (Phaseolus acutifolius) is a great source of resistance against A. obtectus to improve dry bean production. We developed two F2 populations of Phaseolus spp. by crossing bean genotypes resistant to A. obtectus × susceptible, to (1) search for metabolites related to bean weevil resistance using an untargeted metabolomics approach and (2) understand the genetics of resistance to A. obtectus attack using the number of adults emerged from seeds as resistance criteria. The segregation of the number of adults emerged from seeds showed that the genetics of resistance (0 emerged adults = resistant, 1 or more emerged adults = susceptible) was controlled by a single dominant gene in two (resistant × susceptible) F2 populations. From nine metabolites detected, pipecolic acid concentration was significantly higher in the testa of resistant individuals than in the testa of susceptible individuals. From a breeding point of view, (P. Saltillo × T. amarillo) F2 is of special interest because it is derived from a cultivated tepary × cultivated common bean cross and showed 3:1 resistant vs susceptible segregation. Therefore, this F2 is a suitable base material for breeding programmes to obtain new bean lines with good agronomic performance, seed quality and resistance to insect attack. Pipecolic acid plays a role in resistance against A. obtectus. [ABSTRACT FROM AUTHOR]

In this study, insecticidal effects of the essential oils obtained from plants Ocimum basilicum L., Rosmarinus officinalis L. and Artemisia dracunculus L. on confused flour beetle (Tribolium confusum du Val., 1863 (Coleoptera: Tenebrionidae)) and bean weevil (Acanthoscelides obtectus (Say), 1831 (Coleoptera: Bruchidae)) adults were tested in laboratory conditions. In this context, T. confusum and A. obtectus adults were exposed to essential oils at 10 and 20 μL/petri doses for 24, 48, 72 and 96 h. All of the essential oils used in the study caused mortalities at different rates in two application doses but end of the 96 h all mortality rates were obtained similar (O. basilicum 98.3%, R. officinalis 98.3%, A. dracunculus 93.3% against T. confusum adults; O. basilicum 100%, R. officinalis 100%, A. dracunculus 100% against A. obtectus adults). It was determined that the effects of essential oils on A. obtectus adults were greater than T. confusum adults. Especially when the dosage was 20 μL, the death rate increased up to over 95% after 96 h for all types. The mortality rates increased with increasing exposure period at the 48, 72 and 96 h. in all applications. The results of the study suggest that essential oils from O.basilicum and R.officinalis could have a potential as control agents against A. obtectus and T.confusum adults under storage conditions. [ABSTRACT FROM AUTHOR]

The bean weevil, Acanthoscelides obtectus (Say (Coleoptera: Chrysomelidae) is pest species which damages especially beans, and chickpea, coriander and cowpea. Acanthoscelides obtectus causes serious problems both in the field and the storage due to its multiple generations. Its causes the decreasing of legumes nutrient value, germination and quality problems and weight loss, addition to making dirty because of its rotting food and feces. It reduces the market value of legumes in the internal and external trades. For these reasons, the manegement of A. obtectus must be carefully carried out in the storage and the field. The control of A. obtectus was primarily regarded to apply the cultural measurement. For this aim, the certified seed and late planting should be applied in the damaged areas because of the pest. The harvesting should not be delayed, and then the lost harvest should be deeply buried or burned. Plant extracts (the extract of eucalyptus oil extract and rosemary tree etc.) should be primarily used as the chemical control. The applications were done for the control of pest as considering the presence of beneficial insects in the leguminous fields. [ABSTRACT FROM AUTHOR]

Sexual dimorphism and specific patterns of development contribute in a great manner to the direction and degree of the sexual differences in body size and shape in many insects. Using a landmark-based geometric morpohometrics approach, we investigated sex-specific morphological size and shape variation in the seed beetle, Acanthoscelides obtectus. We also tested the functional hypothesis of the two morphological modules—thorax and abdomen in both sexes. Female-biased sexual dimorphism in size was shown, while differences in shape were reflected in the wider thorax and abdomen and shorter abdomen in females in comparison to males. The functional hypothesis of a two-module body was confirmed only in females before correction for size, and in both sexes after the allometry correction. Our results indicate that reproductive function has the central role in forming the patterns of modularity. We hypothesize that high morphological integration of the abdomen in females results from intense stabilizing selection, while the more relaxed integration in males is driven by the higher intensity of sexual selection.

Acanthoscelides Schilsky is the large genus of Neotropical bruchid beetles, in which most species show host plant specialization. The species of A. obtectus Say specialized on Phaseolus beans and therefore considered pests. Six legume grain species (Dried common bean, green common bean, lentil, cowpea, broad bean, and soybean) were selected to study the biology of this insect pest on these different legumes under the prevailing environmental conditions of 25 ± 2°C and 60 ± 10% RH. The results showed that an average number of eggs per mated female (fecundity) was recorded in common bean dried and green (26.33 and 22.66 eggs). While the fecundity decreased significantly to 10.00, 9.66 and 4.00 eggs/ female at Soybean, Broad bean and Lentil, respectively. The results also showed that there was a significant difference (p<0.05) in the percentage of emerged adults among the different legume hosts, namely dried common bean and Cowpea the highest value (88.00 and 76.65%) and lowest percentage (17.97%) of emerged adults in green common bean respectively, while no adults emerged in Soybean, Broad bean and Lentil hosts and the developmental periods of A. obtectus on different legume hosts and mean periods varies depending upon the different hosts. [ABSTRACT FROM AUTHOR]

The present study was carried out to know the grain producer perception of the problem of warehouse pests. A semi-structured questionnaire was applied to grain producers in Guanabacoa Municipality, Havana, Cuba. The main grains produced were beans, corn and, to a lesser extent, soybean, sorghum and millet. The lack of specialized facilities for grain storage was significant. It is carried out by artisan methods, standing out the use of plastic containers of different types and size. To this scarce specialization in the conservation of grains, it is added the limited knowledge about sampling methods in warehouses. Only 30 % of the interviewed producers recognized having received training on management of warehouse pests. It implies the need to structure a training program to improve this situation [ABSTRACT FROM AUTHOR]

BACKGROUND: Legumes have been genetically engineered to express α‐amylase inhibitor 1 (αAI‐1) from common bean in their seeds. Whereas the genetically modified (GM) seeds are immune to multiple bruchid pest species, the cosmopolitan bruchid Acanthoscelides obtectus is tolerant to αAI‐1 and their larvae develop normally inside the seeds. Hymenopteran bruchid parasitoids, the most important natural enemies of bruchids, might thus be exposed to αAI‐1 when attacking A. obtectus larvae developing inside GM seeds. Exposure might reduce parasitoid fitness, resulting in a decline in the natural control of A. obtectus, and thus promote the spread of this pest. We investigated the impact of the presence of αAI‐1 in legume seeds on parasitoid fitness in tritrophic experiments with αAI‐1 GM or non‐GM chickpea seeds, A. obtectus, and three parasitoid species. Additionally, we investigated the exposure of parasitoids to αAI‐1 using a fourth, highly sensitive parasitoid species. RESULTS: Parasitoid fitness was not affected when A. obtectus was used in GM chickpea seeds as hosts, and this lack of effects was probably attributable to the fact that exposure of the parasitoids to αAI‐1 was negligible. CONCLUSION: We conclude that the release of GM chickpeas containing αAI‐1 should not harm this important group of non‐target insects. © 2018 Society of Chemical Industry Bruchid parasitoids (in the picture: Heterospilus prosopidis) are not adversely affected by transgenic chickpeas producing the α‐amylase inhibitor αAI‐1 from the common bean for bruchid resistance. [ABSTRACT FROM AUTHOR]

Bean weevil [Acanthoscelides obtectus Say (Coleoptera: Bruchidae)] is considered the main storage pest of the bean crop. Its control is performed mainly by chemical treatment, which has potential to cause resistance in pests, as well as environmental contamination. This study aimed at evaluating the insecticidal and repellent effect of Salvia officinalis L. essential oil against bean weevil. The doses used for the insecticidal test were: 0 L t-1, 0.5 L t-1, 1.0 L t-1, 1.5 L t-1, 2.5 L t-1 and 5.0 L t-1 of bean grains. For the mortality test, the experimental design was completely randomized, in a 6 × 7 (dose × time) factorial scheme, with five replications. The number of dead insects was counted at 2, 6, 12, 24, 48, 72 and 96 h after the insect introduction. The repellency test was conducted in arenas, under a completely randomized design, using the same doses applied to evaluate the insecticidal effect. Counts were performed 24 h after the introduction of insects. The insecticidal effect of the S. officinalis essential oil on A. obtectus resulted in mortality rates higher than 95 %, after 6 h of insect introduction, for all doses tested. Repellency effect was also detected for all doses tested.

The bean weevil Acanthoscelides obtectus Say (Coleoptera: Chrysomelidae: Bruchinae) can cause significant losses in production of its primary host common bean Phaseolus vulgaris L. To avoid bean protection with environmentally risky chemical insecticides and provide sustainable and safe production of food, new pest management methods based on natural compounds are investigated. In the present study, we evaluated protective potential of the essential oil (EO) from the common thyme Thymus vulgaris L. applied on bean seeds. We assessed residual contact toxicity of thyme EO and its effects on A. obtectus longevity, oviposition and adult emergence. Furthermore, to elucidate the role of oxidative stress in thyme EO toxicity, we estimated the levels of oxidatively damaged proteins and lipids, as well as the level of thiols which have important role for antioxidant capacity. We found that thyme oil significantly reduced adult survival and longevity, induced oxidative damage to lipids and proteins and depleted protein and non-protein thiols in a concentration-dependent manner. Females appeared to be more tolerant to thyme oil treatment than males. Sublethal EO concentrations affected oxidative stress indices, deterred oviposition and strongly inhibited adult emergence. The results suggest that thyme oil has the potential to be used as an ecofriendly insecticide for A. obtectus control.

BACKGROUND: The response of virgin females of the legume pest Acanthoscelides obtectus (Coleoptera: Bruchidae) to headspace extracts of volatiles collected from flowers of a nectar plant, Daucus carota, was investigated using behaviour (four‐arm olfactometry) and coupled gas chromatography–electroantennography (GC‐EAG). RESULTS: Odours from inflorescences were significantly more attractive to virgin female beetles than clean air. Similarly, a sample of volatile organic compounds (VOCs) collected by air entrainment (dynamic headspace collection) was more attractive to beetles than a solvent control. In coupled GC‐EAG experiments with beetle antennae and the VOC extract, six components showed EAG activity. Using coupled GC–mass spectrometry (GC–MS) and GC peak enhancement with authentic standards, the components were identified as α‐pinene (S:R 16:1), sabinene, myrcene, limonene (S:R 1:3), terpinolene and (S)‐bornyl acetate. Females preferred the synthetic blend of D. carota EAG‐active volatiles to the solvent control in bioassays. When compared directly, odours of D. carota inflorescences elicited stronger positive behaviour than the synthetic blend. CONCLUSION: This is the first report of behaviourally active volatiles linked to pollen location for A. obtectus, and development of the six‐component blend is being pursued, which could underpin the design of semiochemical‐based field management approaches against this major pest of stored products. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

We studied the insecticidal activity of different concentrations of very high quality natural zeolites (zeolitic rock containing 92 wt% clinoptilolite) applied on dry beans. The test species was adult bean weevils Acanthoscelides obtectus (Say; Coleoptera: Bruchidae), and the variables included different temperatures and humidity regimes. At certain natural zeolite concentrations the adult mortality approached 100% within the first day of exposure. The lethal natural zeolite concentration for 50% adult mortality (LD50) was 1.1 g/kg dry beans 1 d after exposure. The temperature had no significant effects on the insecticidal potential of the tested natural zeolite formulations. The lethal time (LT) for 50% adult mortality (LT50), at a concentration of 0.5 g/kg dry beans was 106.429, 101.951, and 90.084 min at 15, 20, and 25°C, respectively. It did not differ significantly. In contrast, relative humidity (RH) and exposure time as well as their interactions had a significant effect on natural zeolite formulation and insecticidal potential. At a constant concentration of 0.5 g/kg dry beans and 25°C at 23%, 34%, 53%, and 88% RH the LT50 ranged from 61.6 to 75.9 min; at 72% RH the LT50 was 110.6 min. The results indicate that natural zeolite at low concentrations is promising for the control of the bean weevil under different temperatures and RH regimes. [ABSTRACT FROM AUTHOR]

Currently, as a result of anthropogenic activities such as uncontrolled deforestation, industrialization, water pollution, soil, major climate change takes place. Agricultural production will certainly be one of the most affected industries over the next decade. Bean culture is a relatively easy product, versatile, an important source of protein, carbohydrates, some vitamins and micronutrients. In view of these beneficial effects and the high economic value (occupying the third place after soybeans and peanuts for oilseeds), contemporary research sought methods of integrated pest control against bean crops, most notably the bean beetle, Acanthoscelides obtectus. This paper is a review of integrated pest management methods for bean culture in the context of climate change. [ABSTRACT FROM AUTHOR]

Food losses caused by insects during postharvest storage are of paramount economic importance worldwide, especially in Africa. Laboratory bioassays were conducted in stored grains to determine the toxicity of powders of Eugenia aromatica and Moringa oleifera alone or combined with enhanced diatomaceous earth (Probe-A® DE, 89.0% SiO2 and 5% silica aerogel) to adult Sitophilus granarius, Tribolium castaneum and Acanthoscelides obtectus. Adult mortality was observed up to 7 days, while progeny production was recorded at 6–10 weeks. LD50 and LT50 values for adult test insects exposed to plant powders and DE, showed that A. obtectus was the most susceptible towards the botanicals (LD50 0.179% and 0.088% wt/wt for E. aromatica and M. oleifera, respectively), followed by S. granarius. Tribolium castaneum was most tolerant (LD50 1.42% wt/wt and 1.40% wt/wt for E. aromatica and M. oleifera, respectively). The combined mixture of plant powders and DE controlled the beetles faster compared to the plant powders alone. LT50 ranged from 55.7 h to 62.5 h for T. castaneum exposed to 1.0% M. oleifera and 1.0% DE, and 0.5% E. aromatica and 1.0% DE, respectively. Botanicals caused significant reduction of F1 adults compared to the control. Combined action of botanical insecticides with DE as a grain protectant in an integrated pest management approach is discussed. [ABSTRACT FROM AUTHOR]

Effective pest management strategies for a targeted pest species must rely on accurate, reliable and reproducible estimates of population dynamics. Importance of such approaches is even more conspicuous when assessing pest’s potential to utilize other stored products. Using an experimental evolution approach, we have focused our attention on a common bean pest, the seed beetle (Acanthoscelides obtectus). We looked into the potential to invade and sustain population growth on two suboptimal host plants (chickpeas and mung beans). Such an approach simulates steps of the host-shift process in storages. By analyzing population dynamics during initial encountering with a new host plant, we detected a population drop for both novel hosts. However, transgenerational development in a novel environment resulted in a constant population growth in chickpeas, but not in mung bean populations. Reversal of chickpea selected populations to original host plant has led to a severe decrease in population parameters due to low viability of immatures, while the opposite trend was detected in mung bean populations. This paper highlights the importance of good practice in estimating population dynamics for economically important species. With special emphasis on storage pest species, we discuss how this approach can be useful for estimating invading potential of pest insects.

Acanthoscelides obtectus is a common species of the subfamily Bruchinae and a worldwide-distributed seed-feeding beetle. The complete mitochondrial genome of A. obtectus is 16,130 bp in length with an A + T content of 76.4%. It contains a positive AT skew and a negative GC skew. The mitogenome of A. obtectus contains 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes and a non-coding region (D-loop). All PCGs start with an ATN codon, and seven ( ND3, ATP6, COIII, ND3, ND4L, ND6, and Cytb) of them terminate with TAA, while the remaining five ( COI, COII, ND1, ND4, and ND5) terminate with a single T, ATP8 terminates with TGA. Except tRNA , the secondary structures of 21 tRNAs that can be folded into a typical clover-leaf structure were identified. The secondary structures of lrRNA and srRNA were also predicted in this study. There are six domains with 48 helices in lrRNA and three domains with 32 helices in srRNA. The control region of A. obtectus is 1354 bp in size with the highest A + T content (83.5%) in a mitochondrial gene. Thirteen PCGs in 19 species have been used to infer their phylogenetic relationships. Our results show that A. obtectus belongs to the family Chrysomelidae (subfamily-Bruchinae). This is the first study on phylogenetic analyses involving the mitochondrial genes of A. obtectus and could provide basic data for future studies of mitochondrial genome diversities and the evolution of related insect lineages. [ABSTRACT FROM AUTHOR]

Acanthoscelides obtectus (Coleoptera: Bruchidae) is one of the most important post-harvest pests of dry bean Phaseolus vulgaris L. Tepary bean ( Phaseolus acutifolius ) could be a novel source of resistance against A. obtectus to improve dry bean. We studied the resistance of tepary bean varieties to A. obtectus . We focused on three categories of defense: antixenosis, antibiosis, and tolerance. Tepary pinto amarillo (T-amarillo) and Tepary pinto negro (T-negro) beans show high antixenosis to adults, increased numbers paralyzed per hour and per day, and increased duration of development in winter; reduced oviposition, number of emerged adults and adult weight. Due to the small number of emerged adults, there was very little grain weight loss. Volatile compounds were discarded as the cause of paralysis in adults. Adults in T-amarillo and T-negro were paralyzed until day 10 and 14 and then, they die at an exponentially increasing rate. In addition T-negro and T-amarillo produced the highest mortality in larvae before entering the seeds. T-amarillo and T-negro showed antixenoxis, resistance and tolerance to A. obtectus infestation and they can be used as sources of resistance for P. vulgaris breeding. The compound that causes the antixenosis and paralysis in adults is in the testa of the resistant varieties and is not likely to be a volatile compound, whereas the mortality and antixenosis in larvae is caused more probably by a volatile compound present in the testa. [ABSTRACT FROM AUTHOR]