Efficacy of Bacillus thuringiensis and Beauveria bassiana in Controlling Helicoverpa armigera

In the conditions of Khoronk settlement of Armavir marz, Armenia, Helicoverpa armigera (syn. Chloridea armigera Hübner) and Spodoptera exigua (syn. Caradrina exigua Hübner) are the chief pests damaging the pepper plants in their larval stage. In crop season 2022, experiments on these pests in pepper fields tested the insecticides that mainly control the insects. The insecticides tested against Helicoverpa armigera and Spodoptera exigua included Eforia, Belt, Decis F-Lux, and Spintor. The Arrivo served as standard, and the experiment also had a control. As a result of the conducted research, the insecticides Belt, Decis F-Lux, and Eforia showed the highest biological and economic efficiency in controlling Helicoverpa armigera and Spodoptera exigua. The study also ran a biochemical analysis of the pepper harvest to know the effects of the applied insecticides on the peppers’ quality indicators.

BackgroundRecently, due to the development of food security strategies, cotton has been planted in inland saline-alkali dry soils or in coastal some saline-alkali soils in China. Under the condition, to comprehensively prevent and control Helicoverpa armigera in cotton fields with saline-alkali soils, it is important to study the larval growth and development of H. armigera and to study adult oviposition selectivity in H. armigera adults that feed on NaCl-stressed cotton plants.ResultsIn this study, Bt cotton GK19 was used for the experimental group and its nontransgenic parent Simian 3 was used for the control to study the effects of biochemical substances in cotton as well as larval growth and development and adult oviposition selectivity of H. armigera. The experiments were performed by growing cotton indoors under NaCl stress at concentrations of 0 mmol·L− 1, 75 mmol·L− 1 and 150 mmol·L− 1, respectively. The results showed that the expression of Bt protein was significantly inhibited for NaCl-stressed Bt cotton. The content of soluble protein and K+ in the leaves of cotton were decreased, while the content of gossypol and Na+ were increased. In addition, the 5th instar H. armigera larvae exhibited shorten the life span in a 13-day trial period. Under enclosure treatments and at different female densities, the adult oviposition of H. armigera decreased on high NaCl-stressed nontransgenic cotton, while the oviposition on Bt cotton tended to first increase but then decrease under low, moderate and high NaCl stress treatments.ConclusionsUnder certain content ranges of NaCl stress treatments, larval of H. armigera growth and development, and adult oviposition were no significant difference in the change for a certain period. However, under high NaCl stress, larval growth, development and adult oviposition were affected, which may provide insights for the prevention and control of H. armigera for Bt cotton in saline-alkali soils.

Pigeon pea (Cajanus cajan) is an important pulse crop in semi-arid tropical and sub-tropical farming systems, providing high quality vegetable protein, animal feed, and firewood. Insect pests feeding on flowers, pods, and seeds are the most important biotic constraint affecting pigeon pea yields. The present study was conducted in the research Agronomy Farm, RCA, Udaipur, Rajasthan on pigeon pea during Kharif, 2021-22 to observe the Pest succession and efficacy of newer insecticides and organic inputs including botanical and bio-pesticides against sucking pest complex of pigeon pea [Cajanus cajan (L) Millsp.]”. Results revealed that pod borer complex pest were observed in pigeon pea i.e. gram pod borer (Helicoverpa armigera Hübner), plume moth (Exelastis atomosa Walsingham) and tur pod fly (MelanAgromyza obtusa Malloch). Incidence of gram pod borer Tur pod fly and plume moth was observed from 35th (vegetative stage) to 52nd SMW (flowering stage) of the crop. Among all the treatment Chlorantraniliprole 18.50% SC, Flubendiamide 39.35% SC, and Bacillus thuringiensis were the most effective for better control Helicoverpa armigera, Exelastis atomosa Melan Agromyza obtusa Hence, these three pesticides can be suggested to the farmers for effective management of gram pod borer, plume moth and tur pod fly on long duration pigeon pea.

Biodegradable insecticides of Azadirachta indica A. Juss (Meliaceae) can be sustainable alternatives for agriculture. The goal of this study was to develop spray-dried microencapsulated extracts from A. indica seeds and to evaluate their effects in vitro on Helicoverpa armigera Hübner. Five polymeric matrices based on different proportions of gum arabic and maltodextrin were produced and characterized by evaluating photostability profile, drying yield, encapsulation efficiency, water activity, and azadirachtin content. In the photostability study, sample 3 showed the lowest loss of azadirachtin at the end of 15 days (62.90%). In the bioassays, the deterrence percentage was 100%. It was observed that in a 15-day period there was 100% mortality among the caterpillars that had a diet containing about 288 to 576 μg.mL−1 of microencapsulated extract. The microencapsulated extract from A. indica seeds presented increased azadirachtin photostability and showed potential as a bioinsecticide in the control of H. armigera.

Corn is one of the important food crops besides rice. The variety of corn that is in great demand by the public is sweet corn (Zea mays saccharata Sturt). The main pest that often attacks sweet corn plants is Helicoverpa armigera Hubner. Pest control can be carried out using botanical insecticides of tuba roots (Derris elliptica benth.). This research aims to obtain a concentration of tuba root flour extract which was effective against Helicoverpa armigera Hubner. The research was conducted at the Plant Pest Laboratory and Organic Chemistry and Natural Material Laboratory, Faculty of Engineering, Riau University. It was started from January to March 2020. This research used a completely randomized design (CRD) with five treatments and four replications so that 20 experimental units were obtained. The treatments given were various concentrations of tuba root flour extract, namely: 0%, 0.25%, 0.50%, 0.75% and 1%. The results showed that the difference in the concentration of tuba root flour extract had a significant effect on killing Helicoverpa armigera larvae. The concentration of 0.75% is effective in controlling Helicoverpa armigera larvae because it has been able to kill Helicoverpa armigera by 85% with the fastest initial death time at 3.75 hours, lethal time 50 at 17.00 hours after application. Keywords: Root tuba, Helicoverpa armigera , Botanical insecticide

The production of beans and green beans in our country takes place in relatively small areas, and it is additionally reduced by the presence of various harmful agents (pests and diseases). Economically significant diseases of beans and green beans are gray rot (Botrytis cinerea), white rot (Sclerotinia sclerotiorum), seedling rot, and seedling blight (Pythium sp.), Fusarium wilt (Fusarium oxysporumf. sp. phaseoli), bean rust (Uromyces phaseoli), anthracnose (Colletotrichum lindemuthianum), gray leaf spot (Mycosphaerella pinodes), brown leaf spot or bacterial blight (Xanthomonas campestris pv. phaseoli), and bean mosaic virus. Five plant protection products (PPPs) based on four active substances have been registered in our country for the control of pathogens in beans and green beans. Signifi cant pests of beans and green beans in our country are black aphid (Aphis fabae), thrips (Kakothrips robustus), plant aphids (family Aphididae), cotton bollworm (Helicoverpa armigera), as well as red spider mite and Atlantic (strawberry) spider mite (Tetranichus urticae and Tetranichus turkestani). Eight PPPs, based on seven active substances, have been registered for the control of pests in the crop of beans and green beans. This paper aimed to present the registered PPPs in the Republic of Serbia for the control of the most economically important pathogens and pests of beans and green beans, classified according to the mode of action.

У статті представлено результати впливу хімічних і біологічних протруйників на кількісний склад мікробіому ризосфери цукрової кукурудзи протягом її вегетації. Показано, що за використання хімічних препаратів у ризосфері рослин на порядок знижується кількість амоніфікаторів та мікроскопічних грибів у першій половині вегетаційного періоду культури. Вплив ксенобіотиків на вміст актиноміцетів, олігонітрофілів та педоторофів є менш токсичним. У порівнянні з контрольним варіантом вміст даних мікроорганізмів знижувався на 50-75 %, при цьому змін зазнає не лише кількісний, а й якісний склад ризосферної мікрофлори. У той же час досліджувані пестициди не впливали на вміст актиноміцетів і оліготрофів. По мірі розвитку рослин негативний вплив хімічних протруйників на мікрофлору ґрунту поступово нівелювався. Відбувалося відновлення складу ризосферної мікробіоти у кожній умовній функціональній групі мікроорганізмів і до завершення вегетації кукурудзи мікробний ценоз повертався до свого первинного кількісного і якісного складу. Застосування мікробіологічних засобів захисту не призводило до змін чисельності чи дисбалансу у складі ґрунтової мікробіоти. Її кількісний та якісний склад відповідав контрольному варіанту.

Identification of odorant receptors of Tribolium confusum in response to limonene repellent activity

During 2019 and 2020, field experiments were performed on sweet pepper crops to determine the efficacy of chemical insecticides (lambda-cyhalothrin, flubendiamide), semi-synthetic (emamectin benzoate), and biological pesticide (azadirachtin) in controlling cotton bollworm (Helicoverpa armigera). The experiments were performed in a randomized complete block design with four replications according to the standard EPPO method at the site of Veliko Gradiste (Serbia). Flubendiamide was applied at a rate of 50 g/ha, lambda-cyhalothrin at a rate of 7.5 g/ha, emamectin benzoate at a rate of 375 g/ha, and azadirachtin at a rate of 0.75 g/ha. The intensity of the 2nd generation cotton bollworm infestation on sweet pepper at this locality was higher during 2020 compared to 2019. After performing two treatments for the 2nd generation, flubendiamide showed the highest efficacy, ranging from 92.42% (3 days after treatment - DAT, 2020) to 95.56% (9DAT, 2019). Lambda-cyhalothrin had a satisfactory efficacy in the range of 81.93% (9DAT, 2020) to 90.63% (3DAT, 2019), and emamectin benzoate showed similar efficacy from 80.72% (9DAT, 2020) to 90.63% (3DAT, 2019). Azadirachtin could gain a significant place as a botanical insecticide in integrated pest management programs for sweet pepper protection from H. armigera. However, it statistically showed a significantly lower efficacy than other insecticides (77.27%: 3DAT, 2020 to 86.67%: 9DAT, 2019).

Fresh fruits and vegetables, being the source of important vitamins, minerals, and other plant chemicals, are of boundless importance these days. Although in agriculture, the green revolution was a milestone, it was accompanied by the intensive utilization of chemical pesticides. However, chemical pesticides have hazardous effects on human health and the environment. Therefore, increasingly stimulating toward more eco-friendly and safer alternatives to prevent postharvest losses and lead to improving the shelf life of fresh fruits and vegetables. Proposed alternatives, natural plant extracts, are very promising due to their high efficacy. The plant-based extract is from a natural source and has no or few health concerns. Many researchers have elaborated on the harmful effects of synthetic chemicals on human life. People are now much more aware of safety and health concerns than ever before. In the present review, we discussed the latest research on natural alternatives for chemical synthetic pesticides. Considering that the use of plant-based extracts from aloe vera, lemongrass, or neem is non-chemical by-products of the fruits and vegetable industry, they are proved safe for human health and may be integrated with economic strategies. Such natural plant extracts can be a good alternative to chemical pesticides and preservatives.

The extensive utilisation of chemical fertilisers and pesticides in agricultural contexts has precipitated substantial environmental degradation, thereby amplifying the repercussions of climate change. Furthermore, this overuse poses a threat to the sustainability and resilience of global food production systems. The utilisation of microalgae-based biostimulants is a novel and sustainable approach that has the potential to enhance crop productivity and resilience, while reducing dependence on chemical pesticides and their negative effects. The present study evaluated the effectiveness of two novel microalgae-based formulations on the performance of processing tomato (Solanum lycopersicum) crops under field conditions in Spain and Portugal. The formulation comprised enzymatically hydrolysed biomass from L. platensis, N. gaditana and A. obliquus, in combination with olive mill wastewater (alpechin) and aromatic plant extracts. The mixture was applied through drip irrigation and foliar spraying. The application of combined foliar and drip treatments resulted in a substantial enhancement in gross yield up to 51.9%. Concurrently, the acceptable raw material yield demonstrated a notable increase up to 44.9%. Furthermore, an increase in average fruit weight by 2–9 g was recorded. A subsequent foliar nutrient analysis revealed elevated concentrations of N, P, K, Ca, Mg, Fe, and Cu in the plants treated with biostimulants, achieving 3.61, 52.94, 5.96, 36.53, 22.28, 60.41 and 71.32% respectively in the plot L4 with foliar treatment. Although the efficacy of pest control measures was slightly lower than that of conventional pesticides, no significant increase in the incidence of diseased was observed. These findings indicated that microalgae-based biostimulants have the potential to function as sustainable agricultural inputs capable of enhancing crop yields and quality while reducing dependence on chemical fertilisers and pesticides. The outcomes of the study demonstrate the efficacy of microalgae-based formulations in enhancing the yield and quality of tomato crops. This is achieved while maintaining optimal plant health and reducing the reliance on synthetic fertilisers and pesticides.

Introduction to the efficacy evaluation of plant protection products

Intensification efforts in farming to increase productivity must consider the pesticide utilization, especially insecticide and herbicide. Several pestisides which are still used include carbofuran and organochlorine, some of them have lipofilic properties and might harm to human health. Therefore, an effort is required to washing off pesticides from farming products is one of the effort which can be performed. Since pesticides has lipofilic properties, therefore cleaning pesticides with water is not sufficient. Surfactant is required to increase washing off ability of water. Wash off ability of several surfactants circulated on the market i . e. SL, ML and A were investigated. The result showed that the wash off ability values of surfactants to DDT residues on fresh apples were 79.18 %, 75.19 % and 67.49 % for SL, A and ML respectively. The wash off effectiveness of surfactant A, SL and ML to -metrine were 85.29 %, 80.48 % and 64.47 % respectively. Key words: pesticide, cleaning efficiency surfactant, DDT, -metrine.

Transgenic Bt cotton, engineered to continuously produce activated delta-endotoxins of the soil bacteria Bacillus thuringiensis, holds great promise in controlling Helicoverpa armigera and other lepidopteran pests. However, it also may impact the invertebrate community, which needs to be clarified. The effects of Bt cotton on two nontarget insects, Aphis gossypii and Orius sauteri, were assessed under semifield and laboratory conditions. Mean total duration of nymphal stages of A. gossypii was shorter (5.9 versus 6.3 d), and rm was higher (0.418 versus 0.394) on conventional Simian 3 (the most frequently planted non-Bt cotton in northern China) than on Bt transgenic NuCOTN 33B (the first Bt cotton commercially planted in China). Mean duration of fourth-instar O. sauteri was significantly longer on transgenic GK-12 (3.7 d) than on NuCOTN 33B (3.2 d), but no different from Simian 3. Mean total mortality was significantly lower on Simian 3 (3.7%) than on GK-12 (14.8%). During the fourth instar, the predator consumed a significantly higher number of prey on Simian 3 (202.3 prey) than on NuCOTN 33B (159.0), whereas the mean total number of A. gossypii prey consumed during the nymphal stage was significantly higher on Simian 3 (336.8 prey) and GK-12 (330.3 prey) than on NuCOTN 33B (275.7). No detrimental effects were detected on development (nymphs, adults, and progeny eggs), fecundity, longevity, and egg viability of O. sauteri on Bt cotton aphids compared with non-Bt cotton aphids. These results suggest that Bt cotton cultivars GK-12 and NuCOTN 33B have no direct effect on nontargets A. gossypii and O. sauteri. Germplasm divergence may account for the negative effects observed on A. gossypii and O. sauteri when reared on NuCOTN 33B or NuCOTN 33B-fed aphids. The biological meanings of the small difference observed between GK-12 and Simian 3 on survival of O. sauteri will require close monitoring over longer time periods.

A robust integrated pest management (IPM) programme is needed to reduce the use of insecticides in controlling Helicoverpa armigera. Therefore, a 2 year field study was conducted to evaluate the use of alternative control measures (biochemical use) for H. armigera relative to exclusively using chemical insecticides. The entomopathogenic fungus Beauveria bassiana, jasmonic acid and the insecticide chlorantraniliprole were each applied twice during the chickpea growing season. All three applied materials (either alone or combined) significantly (P ≤ 0.05) reduced the larval population of H. armigera and pod infestation. Effects increased with time, and the maximum difference was observed 7 days after the second application in each year. The lowest numbers of larvae per plant and pod infestation were in the B. bassiana 3.21 × 106 + chlorantraniliprole treatment in both 2009/2010 and 2010/2011 year. The reduction in the larval population and pod infestation increased chickpea yield and the highest yield in both seasons, and the maximum yield was obtained in the B. bassiana 3.21 × 106 + chlorantraniliprole treatment. The populations of natural enemies were highest in the jasmonic acid treatment. The results suggest that B. bassiana, jasmonic acid and chlorantraniliprole may be useful components for the H. armigera IPM strategy. © 2016 Society of Chemical Industry.