Callosobruchus Chinensis Research Articles

Insecticidal potency of mixtures of plant powders and Actellic SuperTM (Pirimiphos-methyl + Permethrin) on Callosobruchus chinensis F. and Sitophilus zeamais Motch

Insect pests still cause substantial quantitative and qualitative grain loss ranging from 20 to 100% in small holder farming systems in tropical countries. Synthetic pesticides are recommended as stop gap measures for the management of stored product insect pests. However, their application has not been fully exploited in small scale farming due to environmental, health, and economic concerns. As a result, new researches have shifted focus to exploiting pesticidal plants as alternatives to synthetic pesticides. Therefore, the current study evaluated mixtures of plant powders and reduced amount of Actellic superTM (pirimiphos-methyl + permethrin) as alternative insecticide formulation against Callosobruchus chinensis and Sitophilus zeamais. Green grams and wheat grains were mixed with a mixture of plant powders in the ratios of 1:1, 1:3 and 1:9 to obtain four rates (0.0, 2.0, 6.0 and 10%w/w). Grains and plant powders were also mixed with reduced amount (10, 25, and 50 %) of recommended rate of Actellic SuperTM to obtain dosages as above. Twenty unsexed adults, 1-5 day old S. zeamais and C. chinensis were introduced into treated grains. The mixture of C. lusitanica: T. vogelii powders in the ratios of 1:1, 1:3 and 1:9 caused mortality in C. chinensis of 55, 95 and 85%, respectively. At the same ratio, E. saligna: L. camara mixture produced mortality in S. zeamais of 77, 82, and 85% respectively. In mixture of C. lusitanica and T. vogelii and reduced amount of Actellic SuperTM by 50% the mortality of C. chinensis was 85 and 80 % respectively. Similarly, E. saligna and L. camara and reduced amount of Actellic SuperTM by 50% caused a mortality of S. zeamais of 48 and 97% respectively. The application of plant powders and reduced amounts of synthetic insecticide has the potential to be applied in stored product pest control

Efficacy of combined treatments of abamectin with three inert dusts for the control of Callosobruchus chinensis on cowpea seeds

The insecticidal efficacy of abamectin (AB) and three inert dusts, diatomaceous earth (DE), zeolite (ZE) and kaolin (KA), was evaluated alone and in binary mixtures as stored cowpea protectants against Callosobruchus chinensis. Inert dusts (DE, ZE and KA) were tested at 100, 500 and 1000 mg/kg (ppm), and abamectin was applied at 0.1, 0.25 and 0.5 mg/kg (ppm). Adult mortality of C. chinensis was evaluated after 3 and 7 days of treatment, while progeny production and cowpea seed weight loss were recorded for all tested treatments after 60 days. The mortality of adults in the binary treatments was higher than the individual treatments of inert dusts or AB. Combined treatments of AB at 0.5 mg/kg with DE, ZE or KA at 500 and 1000 mg/kg led to 100% mortality after 7 days of treatment. Moreover, combined treatments of AB (0.25 mg/kg) with KA (1000 mg/kg), AB (0.25 mg/kg) with ZE (1000 mg/kg) and AB (0.5 mg/kg) with KA (100 mg/kg) caused 100% mortality of adults after 7 days of treatment. After 3 days, the binary mixture of AB (0.5 mg/kg) with KA (1000 mg/kg) was the only treatment inducing 100% adult mortality. All treatments with inert dusts, AB, and their binary mixtures caused significant decrease in progeny production of C. chinensis after 60 days of exposure. In particular, treatments with high concentrations induced strong progeny reduction and led to complete protection of cowpea seeds against weight loss and damage caused by C. chinensis after 60 days. Furthermore, no adverse effect on germination was observed in cowpea seeds treated with the highest application rates of inert dusts, AB, and their mixtures. Our findings demonstrated that binary mixtures of inert dusts with abamectin could be successfully used as potential protectants for cowpea seeds against C. chinensis.

Efficacy of Extracts of <i>Shorea robusta</i> and <i>Oroxylum indicum</i> Against <i>Callosobruchus chinensis</i> (L.)

The present study evaluates the efficacy of methanolic plant extracts of Shorea robusta and Oroxylum indicum against the pulse beetle Callosobruchus chinensis (L.). Various phytoactive compounds like alkaloid, terpenoid, flavonoids, saponins, phytosterols, glycoside, phenols and tannins were found in them. The plant extract of S. robuta shows 90% repellency followed by 81.5% with O. indicum at 12%. It was observed that S. robusta shows a potent effect in controlling C. chinensis with 78.30% mortality at 12% followed by O. indicum with 68.30% mortality at 12% concentration.

English

The current research work was conducted for the evaluation of repellent and growth inhibitory potential of Azadirachta indica, Murraya koenigii, Nicotiana tobacum and Liquorice against Callosobruchus chinensis (L.). Each plant extract was tested with four concentrations viz; 5, 10, 15 & 20 % for bioassay experiments. Repellent potentials of acetone extract of the plants were evaluated by using the area preference method against the pulse beetle. The four dilutions of the extracted plant materials (extract) were used at one half of the filter papers (of each) while remaining halves were solely treated with acetone (used as control experimental unit) for the comparison purposes. Data regarding repellence were taken after 12, 24 and 48 hours of the post treatment. In repellency bioassay, the highest (93.32%) repellence of Callosobruchus chinensis was observed for which against 20% concentration of A. indica extract, whereas lowest repellence (78.87%) was recorded in case of Liquorice. Repellency values of 90.07% and 84.76% were recorded in extracts of M. koenigii and N. tobacum in Faisalabad strain. In case of Lahore strain highest repellence of C. chinensis was observed for which 95.16% at 20% concentration of A. indica extract was whereas relatively lowest value (82.04%) was recorded in case of Liquorice. Repellency values of 87.27% and 91.06% were recorded in extracts of M. koenigii and N. tobacum. The results regarding growth inhibitory effect revealed that highest mean progeny inhibition (78.12%) was noted at 20% dose rate of A. indica extracted plant material after longest exposure time (60 days). Comparatively lowest inhibition (28.21%) was noted after 30 days exposure period at 5% dilution of Liquorice extract in Faisalabad strain. Mean inhibition of progeny was found directly dependent on both time as well as concentration, applied. Results revealed that highest mean progeny inhibition (85.03%) was recorded at 20% concentration of A. indica extract after longest exposure time (60 days). Comparatively, lowest inhibition (35.18%) was recorded at 5% after 30 days of application of Nicotiana tobacum extract in Lahore strain. Hence, use of plant-based materials can be helpful for the ecofriendly management of the stored grains insect pests as a part of IPM program.

Study the germination percentage of chickpea seeds infested by pulse beetle Callosobruchus chinensis under laboratory condition

Effect on germination of seeds of chickpea varieties / genotypes were studied under laboratory conditions in the Department of Entomology, College of Agriculture, JNKVV, Jabalpur (M.P.) during 2018-19. The germination was affected due to damage of Pulse beetle (Callosobruchus chinensis). Among all the varieties / genotypes, the healthy seeds of JG 11 x RVSSG 1 and JAKI 9218 were reported with germination of 71.33% (minimum) and 91.33% (maximum), while in the damaged seeds of the same cultivars, the germination was 24.67% (minimum) and 76.67% (maximum), respectively.

Potency of Dioscorea sansibarensis (Dioscoreaceae) Leaf Eluates on Callosobruchus chinensis, Linnaeus 1758 (Coleoptera: Bruchidae) in the Protection of Phaseolus vulgaris (Fabaceae)

Post-harvest losses of stored Phaseolus vulgaris to the bean weevil Callosobruchus chinensis have reached levels of significant concern. Governments and health organisations propose the discovery of reliable, healthy and biodegradable pesticides with higher selectivity and a broad spectrum. This study presents investigations on the activities of Dioscorea sansibarensis leaf extracts on the mortality of C. chinensis and reduction of their egg-laying ability. Laboratory experiments under Completely Randomized Design (CRD) were carried out to determine the mortality and anti-oviposition activity of the vacuum liquid chromatography (VLC) eluates of n-hexane (HE), chloroform (CE), ethyl acetate (EE), n-butanol (BE) and methanol (BE) at different concentrations. Bioassay data were subjected to nonparametric statistical analysis and a generalized linear model at p = 0.05. Statistical results showed that the VLC eluates had a mortality activity of 88.01% (R2 = 0.8801). Treatment by 0.025 g of HE and 0.075 g of CE had 9.60 and 11.50, respectively at p = 0.181. These mortality records were high as to 0.1 g of ME, 0.05 g of EE and 0.075 g of BE that recorded 8.55, 8.45 and 7.80, respectively. Treatments by 0.05 g of CE, 0.025 g of HE, 0.05 g of EE and the positive control recorded mortality of 10.50, 9.60, 8.45 and 8.35, respectively. The highest mortality was observed in the treatment by 0.075 g of HE and 0.1 g of HE with 12.85 and 13.70, respectively at p = 0.377. The VLC eluates had an anti-oviposition activity of 24.98% (R2 = 0.2498) on the C. chinensis. The generalized linear model reported Wald Chi-Square values of 4.363; p = 0.037, 0.711; p = 0.399, 9.125; p = 0.003, 4.363; p = 0.037 on the treatment by 0.025 g of CE, 0.05 g of EE, 0.075 g of BE and 0.1 g of ME, respectively. At p = 0.051, 0.1 g of CE and the positive control attained oviposition of 89.25 and 96.75 respectively. The study presents the first documentation of the lethal activity of D. sansibarensis on the C. chinensis pulse beetle. This could help in the development of Integrated Pest Management (IPM) and could help in the elimination or suppression of the infestation.
 Keywords: anti-oviposition, Callosobruchus chinensis, Dioscorea sansibarensis leaf, mortality, Phaseolus vulgaris, vacuum liquid chromatography (VLC) eluates.

Gas Chromatography-Mass Spectrometry (GC-MS) based Metabolomics of Promising Chickpea Genotypes against Callosobruchus chinensis (L.)

Background: The pulse beetle, Callosobruchus chinensis L. is one of the main biotic threats to chickpea in both field and storage in the world. The evaluation of chickpea genotypes for pulse beetle resistance has increased motivation for the identification and application of host plant resistance as a critical component of pest management. Methods: In the present study, different chickpea genotypes were evaluated under laboratory conditions to identify the antixenosis, antibiosis and GC-MS based untargeted metabolomics of promising chickpea genotypes to the C. chinensis. Result: Genotype NBeG1004 (36.61 eggs/100 seeds) was less prone to egg laying, while ICCV14872 (180.45 eggs/100 seeds) was the most preferred. However, maximal developmental periods, minimum per cent adult emergence and growth index was observed in ICCV92944 Genotype HC1 showed substantial resistance with maximum phenolic, flavonoid and protease inhibitors content. The results revealed that presence of 9-Octadecenoic acid (Z) in HC1 conferred resistance to C. chinensis. These results show assurance for incorporation into an IPM program against C. chinensis.

English

Chickpea is one of the main annual crops in Ethiopia both in terms of its total cultivated area of pulses and its role in direct human consumption. The major problem to increase pulse production is the loss of seed viability and seeds damage from insect infestation particularly Adzuki bean beetle. Research works conducted on diversity study on chickpea varieties grown under different soil fertility levels were scanty. To fill such information gap, hundred chickpea genotypes that were managed under different soil fertility levels for Adzuki bean beetle resistance were screened under laboratory condition at Holetta and Debre Zeit. Cluster analysis was used to group the genotypes into five clusters with and without application of rhizobium and phosphorus, but into six clusters with the application of both rhizobium and phosphorus. Inter-cluster D2 average values of 11.50 (between clusters C4 and C5) to 62.94 (between clusters C2 and C5), 14.85 (between clusters C1 and C2) to 72.12 (between clusters C3 and C5) and 8.61 (between clusters C2 and C3) to 166.25 (between clusters C2 and C6) were found when genotypes grown under neither rhizobium nor phosphorus, only with rhizobium and with rhizobium and phosphorus conditions, respectively. The more divergent the two genotypes are the more will be the probability of improving through selection and hybridization.  The current study showed presence of moderate level of resistance in chickpea genotypes against Adzuki bean beetle regardless of soil fertility levels. In the future, it would be good approach to take up those moderately resistant genotypes in comprehensive breeding programs as a parent for hybridization. Key words: Adzuki bean beetle, chickpea, cluster, diversity, phosphorus, rhizobium.

Post-harvest Management of Cowpea: A potential Cash Crop for the Western Coastal Ecosystem of Goa

Cowpea, popularly grown as Alsando (Red Bold Variety) or Chowli (the less bold cream colored variety) is a major pulse crop of the state of Goa cultivated in the rice fallows during rabi season under residual soil moisture conditions. Harvest and post harvest losses of Cowpea were estimated by primary and secondary data collected from 50 Cowpea farmers from five villages each in the two districts, North and South of Goa and 9 storage godowns in the year 2012-13. The results showed that in spite of the crop being highly remunerative, it was cultivated in only 40 % of the paddy area. The average losses on field were 10.84 % for harvest, followed by 6.96% for threshing and 4.34 % for storage as calculated from primary data collected on farm. Secondary data showed that the awareness of losses during harvest and post-harvest unit operations was very less as they reported zero losses. The pulse has a high storage insect pest, pulse borer (Callosobruchus maculatus, Callosobruchus chinensis)incidence and hence was stored only for seed purpose in some cases for a year and generally disposed of by the month of May in the godowns and by September at household level. In spite of having high returns, high local demand and nutraceutical value, the crop is not grown in large area due to labour intensive unit operations and high pest incidence. Sensitizing the farmers on good management practices and development of a drudgery free harvesting device can make this remunerative crop popular in the state.

Potential of cold plasma to control Callosobruchus chinensis (Chrysomelidae: Bruchinae) in chickpea cultivars during four year storage

Cold plasma has proven itself as a promising method of food preservation by controlling food spoilage bacteria at very low temperatures. It is showing potential for insect control. Synthetic pesticides are mostly used to control Callosobruchus chinensis L. (Chrysomelidae: Coleoptera) to which it has developed resistance. The prospective potential of cold plasma treatment to control pulse beetle infestation of chickpea in the storage for about four years of plasma treatment was studied. The four chickpea cultivars were treated with cold plasma at different power 40, 50, and 60 W each for 10, 15, 20 min. Plasma treated and untreated chickpeas were stored in an airtight ziplock pouch. At regular intervals, the grains were observed for infestation. It was found most effective in controlling the pulse beetle infestation of treated chickpea samples. While plasma untreated chickpeas were attacked and damaged mostly by pulse beetle within the first quarter of the storage study. To avoid the problems created by the use of pesticides cold plasma treatment is found to be the best alternative in the protection of chickpea invasion by pulse beetle during a longer storage period. The findings in the present research may be used for the preparation of legumes which may also soak and cook faster like quick-cooking legumes and preserved for years without invasion of pulse beetle.

Bioefficacy of Three Indigenous Plant Extracts Against Callosobruchus Chinensis L. (BRUCHIDAE: COLEOPTERA)

Results of the evaluation on bioefficacy of three indigenous plant extracts for toxicity and residual effects against the pulse beetle, Callosobruchus chinensis L. (Bruchidae: Coleoptera) showed that the plant extracts had toxic and residual effects for controlling pulse beetle. Mortality and residual effects were statistically different among the plant extracts and doses applied. Neem extract showed the highest adult mortality (36.78%) whereas eucalyptus extract showed the lowest (22.75%). The order of the toxicity of three plant extracts was found as neem > custard apple > eucalyptus. Mortality was found directly proportional to the hour after treatments which increased with the progress of time. Between two solvents, acetone solvent possessed the highest toxicity (mortality 32.95%) but methanol showed the lowest toxicity (mortality 30.56%). The residual toxicity was evaluated on the basis of egg laid, adult emergence, seed infestation and weight loss caused by the insect. The highest residual toxicity was found in neem extract with acetone while the lowest in eucalyptus extract with acetone. Neem extract with acetone and custard apple extract with methanol solvent were found effective to toxic and residual effects against pulse beetle of three plant extracts applied.
 Asiat. Soc. Bangladesh, Sci. 46(1): 1-12, June 2020

Insecticidal, Oviposition Deterrent and Antifeedant Property of Certain Plant Extracts against Pulse Beetle, Callosobruchus chinensis Linn. (Coleoptera: Bruchidae)

Background: The bruchid Callosobruchus chinensis (L.) is one of the major store grain pest of pulses capable of attacking wide range of legumes viz., green gram, black gram, chick pea and pigeon pea and causes 50 per cent damage during storage within 3 to 4 months. The infestation starts in the field, but heavy damage is done in storage. Hence, the current study was aimed to evaluate the insecticidal, oviposition deterrent and antifeedant activity of certain plant extracts against pulse beetle, C. chinensis under storage condition.Methods: The aquous extracts (10%) of Vitex negundo, Pongamia glabra, Cassia angustifolia and Calotropis gigantea were evaluated against the pulse beetle, Callosobruchus chinensis Linn. were carried out at the Department of Agricultural Entomology, Imayam Institute of Agriculture and Technology, Thuraiyur during 2019-20. The commercial product Azadirachtin was kept as a check and the mortality rate was assessed every 24 Hours after treatment (HAT) for three days.Result: The mortality rate after 72HAT was 85.8-87.5% with V. negundo, followed by C. angustifolia (73.33-80.00%) and P. glabra (70.0-75.0%). Azadirachtin gave 100% mortality of the beetle. The oviposition deterrence percentage for pulse beetle, C. chinensis was found to be highest in Calotropis gigantea (37.66-68.16%) followed by Pongamia glabra (30.91-41.50) and Vitex negundo (7.58-46.75) per cent, respectively. The antifeedant activity for pulse beetle was found to be very high when treated with Azadirachtin where there was no food consumption. This was followed by V. negundo (0.1g) and C. angustifolia (0.2g).

Synthesis and Biological Evaluation of Thymol Functionalized Oxadiazole thiol, Triazole thione and β-lactam Derivatives

In the present study, different derivatives of thymol (1) viz. hydrazide (2), oxadiazole thiol (3), triazole thione (4), hydrazones (5-7), and β-lactams (8-10) were synthesized. All synthesized compounds were identified and characterized using elemental analysis, UV-Visible, <sup>1</sup>H NMR, <sup>13</sup>C NMR, and IR spectroscopic techniques. Synthesized thymol derivatives were evaluated for antifungal potential against phytopathogenic fungi Fusarium moniliforme, Rhizoctonia solani, and Dreschlera maydis of maize in comparison to recommended standards in terms of percent inhibition and ED50 values. Thymol was more effective as compared to its derivatives against all three tested fungi. Hydrazones (5-7) and β-lactams (8-10), having m-NO<sub>2</sub> substituted phenyl ring (6, 9), were less effective as compared to o-NO<sub>2</sub> and p-NO<sub>2</sub> analogs against F. moniliforme and R. solani, however, the reverse trend was observed against D. maydis. Thymol and its derivatives were also tested for insecticidal activity against stored grain (chickpea) insect Callosobruchus chinensis and various parameters viz. egg laying, adult emergence, and grain damage were recorded and compared. Compounds having oxadiazole thiol (3) and triazole thione (4) moiety showed promising effects against insect C. chinensis.

Application of clove and dill oils as an alternative of salphos for chickpea food seed storage

Mycological investigations of 25 samples of stored chickpea food seeds (Cicer arietinum L.) from grocery stores of Gurgaon and Gorakhpur revealed occurrence of seventeen fungal species belonging to genus viz., Alternaria, Aspergillus, Chaetomium, Colletotrichum, Curvularia, Fusarium, Penicillium, Rhizopus, Rhizoctonia, and Sclerotium. In these Aspergillus flavus, A. niger, Fusarium oxysporum had dominance in terms of per cent occurrence. Only one species of Bruchid (Callosobruchus chinensis L.) occurred in all the 25 samples. The biodeterioration of seeds inoculated with fungi: A. flavus, A. niger, F. oxysporum and the insect—C. chinensis, revealed their role in seed deterioration. For chickpea food seed protection essential oils were extracted from edible commodity(clove(Lavang and dill(sowa) leaf). Clove(Lavang) oil registered highest antifungal activity inhibiting (100%) mycelial growth of fungi, viz. species Aspergillus flavus, A. niger, Fusarium oxysporum at 300 ppm but was fungicidal at 400 ppm. Dill (Sowa) oil showed complete inhibition at 400 ppm and was fungicidal at 500 ppm. While mixture of both the oils (clove and dill) showed complete inhibition (100%) and fungicidal action at 400 ppm against the dominant fungi. The oils showed 100% insect repellent activity and were found fungicidal at 0.02 ml dose and also insecticidal. The mixture of oils was cidal at 0.02 ml dose. The mixture of oils showed a broad antifungal spectrum at 500 ppm while only 70–93% inhibitory activity at 300 ppm. The oils' mixture's activity was not affected by temp, storage and autoclaving up to 150 days. Oils physico-chemical properties were studied. GC–MS analysis of clove(Lavang) oil depicted major components: 75.63%eugenol while dill(sowa) leaf oil had 25.14% apiole. Formulation of Mixture of oils was more effective showing complete seed protection i.e.no growth of fungi and insects upto 150 days storage than salphos (150 days). While salphos controlled only maximum three fungi (A. terreus, C. dematium, F. moniliforme). The formulated oils mixture did not have any adverse effect on the chickpea seeds and increased their shelf life.

Management of pulse beetle, Callosobruchus chinensis L. in storage on different mungbean varieties of Bangladesh

Management of pulse beetle, Callosobruchus chinensis L. in storage on different mungbean varieties of Bangladesh

Evaluation of traditional method of stored product protection: Effect of mixing tef (Eragrostis tef) grains with stored chickpea on occurrence of Adzuki bean beetle (Callosobruchus chinensis) and its natural enemies

The effect of a traditional stored chickpea protection method on occurrence of Adzuki bean beetle and its natural enemies was studied using cultivars Natoli and Arerti. Quncho, a white-seed tef, was admixed with chickpea grain on replacement basis at the rate of 0% (10 kg chickpea grain), 5%, 10%, 15%, 20%, 25%, and 30%. Each treatment was replicated three times and arranged in two factors nested design. None of the chickpea–tef mixture treatments did affect the occurrence of Adzuki bean beetle and its natural enemies; while chickpea cultivar significantly affected all studied variables. Thus, there were lower numbers of grains with eggs; eggs per grain; grains with holes; holes per grain; Adzuki bean beetle emergence holes per grain; and natural enemy emergence holes per grain on grains of Arerti than on grains of Natoli. But percentage parasitism was markedly greater on Arerti than Natoli. Anisopteromalus calandrae and Dinarmus basalis were the natural enemies of Adzuki bean beetle found in chickpea–tef mixture and together they caused up to 98% larval parasitism in grains of Arerti and 56% in Natoli.

Application, Reactivity and Synthesis of Isoxazole Derivatives

In this review article, we describe the application, reactivity and synthesis of isoxazole derivatives, more specifically, the application, reactivity, and synthesis of 3,5-disubstituted, 3,4- disubstituted, and 3,4,5-trisubstituted isoxazole using the green method. We review the application of isoxazole in material science, agriculture and pharmaceutical. In material science, isoxazole is used as a photochromic, electrochemical probe for Cu<sup>2+</sup> and, given its optical properties, in dye-sensitized solar cells, high energy material and liquid crystal. In agriculture, isoxazole is used as an insecticide for managing Callosobruchus chinensis, Acaricidal activity against T. cinnabarinus, and herbicidal activities of 2-cyanoacrylates containing isoxazole. In pharmaceutical, isoxazole shows anticancer, antituberculosis, anti-inflammatory, and acetylcholinesterase inhibitors. Further, we describe various reactions of isoxazole such as ring opens, bromination and iodination, thioynol ethers, intramolecular SEAr reaction, arylation, cycloaddition and photocycloaddition, photoisomerization, Domino transformation of isoxazoles to 2,4-dicarbonyl pyrroles and rearrangement. We also describe the synthesis of 3,5-disubstituted, 3,4-disubstituted and 3,4,5-trisubstituted isoxazole using different methods.

Pesticidal efficacy, mode of action and safety limits profile of essential oils based nanoformulation against Callosobruchus chinensis and Aspergillus flavus

The study explores the pesticidal efficacy, mode of action, and safety limit profile of essential oils-based formulation using the combination of Myristica fragrans (M), Bunium persicum (B), and Zanthoxylum alatum (Z) (1:1:1 v/v/v) and their nanoformulation (Ne-MBZ) against the Callosobruchus chinensis, Aspergillus flavus and aflatoxin B1 production. Linalool, γ-terpinene, and cuminaldehyde were identified as the major compounds of the formulation (MBZ) by Gas chromatography-mass spectrometry (GC–MS). Nanoencapsulation of developed formulation (Ne-MBZ) was prepared using chitosan and characterized by scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), and Fourier transform infrared spectroscopy (FTIR). The pesticidal efficacy of nanoformulation (Ne-MBZ) against C. chinensis IC50 (0.14 μl/ml), A. flavus (0.8 μl/ml) and AFB1 (0.8 μl/ml) was significantly higher in both in-vitro and in-situ conditions than the sum of their individual revealing a notable synergistic effect. Besides, the detailed mode of pesticidal action and safety limit profile were explored using biochemical, in-silico and ADMET (absorption, distribution, metabolism, excretion, and toxicity) approaches.

Genetic analysis of seed resistance to Callosobruchus chinensis and Callosobruchus maculatus in cowpea

Callosobruchus chinensis (azuki bean weevil) and Callosobruchus maculatus (cowpea weevil) are the most destructive pests that cause significant losses to cowpea (Vigna unguiculata) seeds during storage. Development of cultivar(s) resistance to bruchids is a major goal in cowpea breeding program. Cowpea accession “TVu 2027” has been identified as moderately resistant to C. maculatus. Genetic studies of the seed resistance in this accession using strains of C. maculatus from Africa and America have demonstrated that the resistance is controlled by one or two recessive genes. However, there is no reports on genetics of the resistance to C. chinensis and to strain(s) of C. maculatus from Asia. Therefore, the objective of this study was to investigate genetics of the resistance to C. chinensis and C. maculatus in TVu 2027. TVu 2027 (P2) and PK2015VTN001 (P1; susceptible cowpea) were used to develop six basic generations (populations), viz. P1, P2, F1 (P1 × P2), F2 (P1 × P2), BC1P1 (P1 × F1) and BC1P2 (P2 × F1). The population were evaluated for percentage of damaged seeds (PDS) and area under the disease progress stairs (AUDPS; indicating infestation severity) by C. chinensis and C. maculatus. The results showed that TVu 2027 was moderately resistant to both bruchid species. Broad-sense heritability for PDS and AUDPS was moderate, being 70% and 73% for C. chinensis, respectively, and 64% and 61% for C. maculatus, respectively. Number of genes controlling C. chinensis resistance and C. maculatus resistance was two genes and one gene, respectively. Generation mean analysis revealed that genes with additive effect and additive × dominance gene interaction are involved in the resistance to both bruchid species. Correlation analysis suggested that the genes controlling resistance to C. chinensis and those conferring resistance to C. maculatus are unlinked.

Film seeds coating with hexane extracts from Illicium verum Hook.f. and Syzygium aromaticum (L.) Merrill & Perry for controlling Callosobruchus maculatus (F.) and Callosobruchus chinensis L.

The application of film seed coating with some plant extracts against stored insect pests was an alternative approach for insect protection instead of using chemical insecticides. The overuse of insecticides has contributed to both human health and environmental problems. The hexane extracts of Illicium verum (HS) and Syzygium aromaticum (HC) were evaluated against bruchid beetles (Callosobruchus maculatus and Callosobruchus chinensis). The insecticidal activities and enhancing seed germination after being coated by various concentrations of extracts, purified fraction (PF) of extracts, standard chemicals of PF, fipronil insecticide (FI), and coating agent groups were evaluated after stored. Both HS and HC at 3% concentrations were more effective against C. maculatus than C. chinensis with LT50 values of 1.60-1.90 and 3.44-3.62 h, respectively. They could also kill those insects with a higher number than that of standards. The HS and HC could inhibit the progeny population of those insects over 95.6% with no significant difference compared to the FI group. The eugenol standard was the most effective and completely inhibited the emergence compared with trans-anethol standard and PFs. The seed that was coated with 1% of HS and stored at 4 °C for 6 months showed no effect on seed germination with no significant difference between FI and control groups. The application of 1% of HS incorporated in the film seed coating against bruchid beetles and did not affect seed germination quality after 6 months. © 2021 Society of Chemical Industry.