Galleria mellonella, the greater wax moth has always been an important pest against honeybees and has remained a nightmare for beekeeping farmers. Management of G. mellonella in live honeybee colonies is very difficult because most current management practices can destroy whole honeybee colonies. In the present study, experiments were conducted to isolate and characterize Bacillus thuringiensis from infected greater wax moth cadavers and to evaluate their biocontrol ability against G. mellonella. The bioefficacy of these isolates has been evaluated against greater wax moth along with the standard strain HD-1. Among all the strains tested, NBAIR BtGa demonstrated higher efficacy compared to other strains, with an LC50 value of 125.17 µg/ml, whereas HD-1 exhibited a significantly higher LC50 value of 946.61 µg/ml. Considering the economic importance of NBAIR BtGa we performed whole genome sequencing of this strain resulting in the identification of a genome size of 5.96 Mb consisting of 6888 protein-coding genes. Gene ontology analysis categorized these genes into three groups based on their roles, i.e., biological functions (2169 genes), cellular components (1900 genes), and molecular functions (2774 genes). Through insecticidal toxicity-related genes (ITRG) profiling of our strain across the genome by Bt toxin scanner and cry processor resulted in the identification of several Cry proteins namely Cry1Ab11, Cry1Ia44, Cry1Aa2, Cry2Af1, Cry1Da2, Cry1Eb1, Cry1Ab5, Cry1Cb2, Cry1Ac2. Besides Cry proteins, other ITRG genes, viz. Vip3Bb2, Zwittermicin A resistance proteins, Chitinase C, Mpp46Ab1, immune inhibitor A, Bmp1, Vpb4Ca1, and Spp1Aa1 were also reported, which show toxicity against lepidopteran pests. The studies were also conducted to test the biosafety of Bt toxins against honeybee larvae and adults, which showed strain NBAIR BtGa was more than 99
In agriculture crop ecosystems, pollination is the foremost fundamental activity performed by fascinating creatures like bees, butterflies, hoverflies, birds, and bats, ensuring reproductive success in angiosperms. Currently, most pollinators appear in red data books as their population and abundance deplete in the ecosystems. Threats like habitat loss, climate change, urbanization, use of chemical pesticides, pests, and diseases drove their extinction. The decline in the pollinator population may considerably decrease global food production and productivity. Effective and efficient conservation strategies are the key elements to mitigate the threats faced by pollinators in the promotion of pollinator resilience. Here, we explored various conservation strategies that restore the pollinator habitat by following sustainable agricultural practices and some policy interventions. Public awareness and collaborative efforts among governments, NGOs, and the private sector are crucial for successfully implementing and adapting these conservation strategies. By acclimatizing an integrated, collaborative, and convincing approach to pollinator conservation, we can assure and predict ecosystem sustainability and productivity, which eventually supports biodiversity and food security.
Abstract Background Melon fruit fly, Zeugodacus cucurbitae Coquillett (Diptera: Tephritidae), is a devastating polyphagous pest attacking large number of fruits and vegetables causing huge economic yield losses across the world. Management of this notorious pest is very challenging as the larvae feed inside the fruit. Hence, the present research study aimed to screen the indigenous Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) strains causing toxicity to larvae and to identify the insecticidal toxicity-related genes present in respective strains. In the present study, 50 indigenous B. thuringiensis (Bt) strains along with one reference strain were screened against second-instar larvae Z. cucurbitae. All the strains were analyzed for presence of 21 dipteran active cry genes. Results Mortality in Z. cucurbitae larvae due to Bt strains ranged from 16 to 92%. PCR results revealed that each strain tested positive for a minimum of three cry genes to maximum of nine cry genes. Among the cry genes, cry1A, cry2A, cry1C, cry19, cry11 and cry70 were detected in high frequency of 100, 88, 84, 74, 58 and 54%, respectively. Bioassay studies revealed that ten out of fifty strains displayed more than 50% mortality. Hence, these ten strains, along with the reference strain, were further tested for mortality for the calculation of the median lethal concentration (LC50). The LC50 values ranged between 38.48 and 105.18 μg/ml. The lowest LC50 found for the strain NBAIR Bt107 was 38.48 μg/ml and was on par with the reference strain (Bti 4Q1) (31.3 μg/ml). Conclusion Indigenous Bt strains displayed a toxicity against the larvae of Z. cucurbitae. The probable dipteran active cry genes responsible for toxicity were interpreted. Thus, the Cry toxins from Bt can play a very important role in the management of Z. cucurbitae.
Bacillus thuringiensis is the most widely used biopesticide, targets a diversity of insect pests belonging to several orders. However, information regarding the B. thuringiensis strains and toxins targeting Zeugodacus cucurbitae is very limited. Therefore, in the present study, we isolated and identified five indigenous B. thuringiensisstrains toxic to larvae of Z. cucurbitae. However, of five strains NBAIR BtPl displayed the highest mortality (LC50 = 37.3 μg/mL) than reference strain B. thuringiensis var. israelensis (4Q1) (LC50 = 45.41 μg/mL). Therefore, the NBAIR BtPl was considered for whole genome sequencing to identify the cry genes present in it. Whole genome sequencing of our strain revealed genome size of 6.87 Mb with 34.95
Bacillus subtilis is a Gram-positive bacterium known for its antagonistic attributes, particularly through the production of various secondary metabolites, including lipopeptides. In this study, we investigated the antagonistic capabilities of B. subtilis strain NBAIR-BSWG1 with a focus on assessing the efficacy of NBAIR-BSWG1 in combatting Sclerotium rolfsii. Our findings demonstrated substantial inhibitory effects, with 82.73% to 100% reduction in S. rolfsii growth when exposed to NBAIR-BSWG1 at concentrations ranging from 50 to 100 µL/mL in poison food technique. In dual culture assay, NBAIR-BSWG1 exhibited a significant 55.50% inhibition of S. rolfsii. Moreover, pot experiments revealed a promising 26% reduction in disease incidence. This study underscores the significant role of NBAIR-BSWG1 in controlling S. rolfsii, holding substantial potential for developing effective formulations aimed at mitigating the southern blight of tomatoes.
Background Among all the coconut pests, rhinoceros beetle causes acute and serious damage to coconut palm. Management of this pest is very difficult due to its nocturnal activity, and also, it damages the emerging leaf inside the bud. Management of rhinoceros beetle using entomopathogens will be of great importance as it is economical and ecofriendly. Studies were carried out to decipher the biocontrol potential of indigenous entomopathogenic bacterium ( Bacillus thuringiensis ) and entomopathogenic fungi ( Metarhizium robertsii and M. majus ) against Oryctes rhinoceros in the field, individually as well as in combination, by soil drench as well as by topical spray method. Results The study showed that B. thuringiensis strain NBAIR-BTAN4 showed 24.8% mortality at 5th week in soil drench method and 24% mortality in topical spray method. M. robertsii showed 24% mortality at 5th week in soil drench method as well as topical spray method. Similarly, M. majus showed 24% mortality in soil drench method and 23.2% in topical spray method at 5th week. In combination, NBAIR-BTAN4 + M. robertsii showed 40.8 and 44% in soil drench and topical spray method at 5th week, respectively. Combination of NBAIR-BTAN4 + M. majus showed 44.8 and 40.8% in soil drench and topical spray method at 5th week, respectively. Combination of NBAIR-BTAN4 + M. robertsii + M . majus showed 52.8 and 57.6% mortality at 5th week in soil drench and topical spray method, respectively. Conclusion The present study showed application B. thuringiensis in combination with M. robertsii and M . majus is effective in management rhinoceros beetle in coconut orchard. Study also indicated that soil drench method is more promising strategy than topical spray method in managing larval population of the beetles and also confirmed that B. thuringiensis , M. robertsii and M. majus are compatible and they seemed to have a synergistic effect in controlling the pest in coconut orchard.
Aims: The current study was conducted to know the compatibility of natural enemies and botanical for management bhendi fruit borers in the bhendi field. Study Design: Randomized Complete Block Design (RCBD). Place and Duration of Study: Experiment conducted during 2019-20 and 2020-21 at ICAR- National Bureau of Agricultural Insect Resources, Hebbal, Bengaluru, Karnataka, India. Methodology: Two field tests were conducted at the entomological research farm, ICAR-NBAIR Bengaluru, Karnataka, India, to know the compatibility of the natural enemies (Trichogramma chilonis Ishii (Hymenoptera:Trichogrammatidae) , Chelonus blackburni (Cameron) and Bracon brevicornis (Wesmael) (Hymenoptera: Braconidae) and botanical (Neem oil 0.5%) for management of E. vittella and H. armigera on bhendi. Arka Nikita (IIHR) bhendi variety was used for the two trials with different treatments in four replication. The release rates of parasitoids were decided based on the previous parasitic potential studies. Results: In the first trial, among the treatments, a combination of T. chilonis + C. blackburni + B. brevicornis and C. blackburni + B. brevicornis recorded the lowest pooled mean larval population reduction over pre-treatment count of E. vittella and were on par with each other, recording 40.19% and 37.27%, respectively followed by T. chilonis + B. brevicornis (31.28%), C. blackburni (30.90%), B. brevicornis (28.64%), Neem oil 0.5% (27.71%), Neem oil 0.5% + B. brevicornis (25.46%) and T. chilonis (25.32%). A similar trend was also observed in combination of T. chilonis + C. blackburni + B. brevicornis and C. blackburni + B. brevicornis against H. armigera, which accounted for 47.19% and 37.22% of reduction over pre-treatment count in the respective treatment combination of parasitoids. The next best treatments were T. chilonis + B. brevicornis (28.21%), C. blackburni (26.56%), B. brevicornis (22.21%), Neem oil 0.5% (20.37%), T. chilonis (17.31%) and Neem oil 0.5% + B. brevicornis (16.07%) Conclusion: From this study we recommend that, for bhendi fruit borers management, release of parasitoids like T. chilonis + C. blackburni + B. brevicornis at 50,000+1000+1000 adults/ha, respectively in bhendi field starting from 35 DAS at 15 days’ intervals of duration, two-time release of parasitoids is enough later, they have augmented and reduce the population of fruit borer larvae effectively.
Aims: The current study was carried out to investigate the parasitic potential of density of two important parasitoids against the age of two important bhendi fruit borer pests. Study Design: Completely Random Design (CRD). Place and Duration of Study: The study was conducted during 2019-20 and 2020-21 at bio control laboratory of National Bureau of Agricultural Insect Resources (ICAR) Hebbal, Bengaluru (Latitude: 13.097221 Longitude: 77.568291) by adopting standard methodology and materials. Methodology: An experiment was designed to examine the effects of parasitoid densities of Bracon brevicornis and Chelonus blackburni on the host age (different instars) larvae of fruit borers two important fruit borers by checking the the percent parasitization. The second, third, and fourth instar larvae of E. vittella were introduced separately at different ratios of Bracon brevicornis parasitoids and host viz., 1:10, 2:10, 3:10, 4:10, and 5:10. Mated female parasitoids were utilised in all cases, and the experiment was carried out in a glass jar of 18 x 12 cm, using the sandwich approach. [1] with four replications. After 24 h, the larvae were observedand the percent parasitization was calculated. The same parasitoids were used for thesecond, third, fourth, and fifth instars larvae of H. armigera. To examine the parasitic potential of C. blackburni, another experiment was conducted with various ratios of its adults and eggs of E. vittella and H. armigera by adopting the procedure of Swamiappan and Balasubramanian [2]. The parasitoid and host eggs were maintained at a ratio of 1:100, 2:100, 3:100, 4:100, and 5:100 with four replications. The observation of percent parasitization was recorded after the egg incubation period. Results: The parasitic potential studies showed that the parasitoid host ratio of 5:10 (100%) was the best for E. vittella (II, III and IV instar larvae) with the highest parasitization followed by 4:10 (96.83 %), 3:10 (85.08 %), 2:10 (61.71 %) and least parasitization was observed in 1:10 parasitoid host ratio (52.71 %). Similarly, for H. armigera (II, III, IV and V instar larvae) parasitoid host ratio of 5:10 was recorded the highest parasitization (96.75 %), followed by 4:10 (93.69 %), 3:10 (84.11 %), 2:10 (64.75 %) and least parasitization was observed in 1:10 parasitoid host ratio (45.07 %) The parasitic potential of C. blackburni revealed that the 5:100 parasitoid host ratio resulted in the maximum parasitization of 64.75% against E. vittella, followed by 4:100 (60.50%), 3:100 (52.55%), 2:100 (38.27%), and 1:100 (25.60%). Similarly, for H. armigera, parasitization was highest at a parasitoid host ratio of 5:100, followed by 4:100 (64.50%), 3:100 (58.25%), 2:100 (43.45%), and 1:100 (28.50%). Conclusion: The parasitoids: host ratio of 5:10 for B. brevicornis and 5:100 for C. blackburni is optimal for managing the bhendi fruit borer complex at the IV instar level.
During the surveys undertaken in July-September 2020, a braconid solitary koinobiont endoparasitoid, Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae: Euphorinae) was found parasitizing the invasive pest, fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) in maize. Meteorus pulchricornis is a new addition to the known and rapidly expanding parasitoid complex of FAW in India. The present study provides morphological identification details of M. pulchricornis along with comparison notes of other closely allied and confusing species.
Two indigenous entomofungal strains each of Beauveria bassiana and Metarhizium anisopliae were tested for their pathogenic effect on Aak grasshopper, Poekilocerus pictus, Fabricus, 1775 (Orthoptera: Acrididea) under laboratory conditions. Among the four isolates tested, M. anisopliae ICAR-NBAIR Ma-4 and ICAR-NBAIR Ma-35 caused 100 and 90% mortality, respectively, whereas B. bassiana ICAR-NBAIR Bb-78 and ICAR-NBAIR Bb-45 showed 40 and 14% mortality, respectively. ICAR-NBAIR Ma-4 and ICAR-NBAIR Ma-35 isolates were further tested on eggs of grasshoppers which showed 72.7 and 59.8% mortality respectively. Dose and time mortality studies with ICAR-NBAIR Ma-4 showed LC50 value of 1.52 × 103 spores/ml and LT50 of 68.17 h at dose of 1 × 108 spores/ml. ICAR-NBAIR Ma-35 showed LC50 value of 2.09 × 103 spores/ml and LT50 of 87.10 h at dose of 1 × 108 spores/ml. The use of isolate ICAR-NBAIR Ma-4 as a potential control agent of Poekilocerus pictus with a lower LC50 which killed faster half of Poekilocerus pictus individuals. This isolate can be further tested against the devastating invasive desert locust, Schistocerca gregaria for its management on the eggs and early hopper stages.
New challenges appear with every biological invasion and presses need to probe their ecological interactions. In the comprehensive yet complicated food web associated with the niche of the recently invaded cassava mealybug (CMB) Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae), there was a multitrophic interaction structured vertically as well as horizontally. Altogether 45 species: thirty four species of insects from six orders (Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, and Neuroptera) and eleven species of spiders (Araneae) were grouped under four trophic levels into 11 guilds. The analysis of trophic guild structure and interaction indicated that many indigenous parasitoid species, which qualified to be placed under the fourth trophic level, actively parasitized the potential native predators of cassava mealybug (CMB) and thereby negatively impacted the natural biological control of CMB. Most of these resident hyperparasitoid species were recorded for the first time, to be associated directly or indirectly with CMB. The species diversity at fourth trophic level could be viewed as a bioindicator and one of the most important determinant factors on the success rate of any biological control program. No indigenous primary parasitoids were documented on CMB from any of the sites sampled. In the absence of any indigenous parasitoids and high level of parasitization of the potential CMB predators, the long-term and indirect ecosystem risks will be significant until the introduction and establishment of the proven classical biological control agent, Anagyrus lopezi (De Santis) (Encyrtidae: Hymenoptera) from other countries.
Rugose spiralling whitefly (RSW), Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae), an invasive pest to the Oriental region was found infesting several plantation crops like coconut, banana, guava, Indian almond, sapota, oil palm, mango, cashew, custard apple and several ornamental plants in southern states of India as well as Assam, West Bengal, Maharashtra, Meghalaya, Odisha, Chhattisgarh and Gujarat. Intensive surveys across different agroclimatic zones of Karnataka revealed that infestation of the pest was severe in coastal and southern region of Karnataka compared to northern region. Molecular characterization of partial mitochondrial cytochrome c oxidase–I gene (658 bp) and morphological characters of the pest and its natural enemies confirms its identity. During the study, 35 host plants were recorded, and several natural enemies viz., parasitoids, Encarsia guadeloupae, Encarsia dispersa (Hymenoptera: Aphelinidae), predators, Pseudomallada astur (Neuroptera: Chrysopidae), Jauravia pallidula, Cheilomenes sexmaculata (Coleoptera: Coccinellidae) and Cybocephalus indicus (Coleoptera: Cybocephalidae) were also observed feeding on RSW. The parasitoid E. guadeloupae was the major parasitoid associated with the pest. Natural parasitism by the parasitoids was ranging from 7–80% in the study area.
Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a polyphagous pest invaded India and seriously threatened maize and other crops. The detailed information on its occurrence and damage severity in the invaded regions are limited. In this study, we assessed the occurrence, incidence and damage severity of fall armyworm in 126 maize fields in 10 districts of Karnataka during the rainfed condition. Further, potential co-occurrence of this pest with native stem borers and its natural enemies explored to tackle this pest. Survey reports revealed that the fall armyworm was well distributed across the maize growing regions of Karnataka with 44-100% field infestation. The damage incidence of S. frugiperda was 22.13-46.83% with damage severity 0 to 4.9 on the 0 to 9 scale. The larval count was 0.93 +/- 0.17 to 3.07 +/- 0.58 per 10 plants across the locations. The co-occurrence of S. frugiperda with the native maize stem borers, Chilo partellus (Swinhoe) and Sesamia inferens (Walker) was less than 5% of the plants. It shows that S. frugiperda had dominated the native stem borers causing significant damage to maize. This study found five parasitoids parasitizing the egg, egg-larval, larval and larval-pupal stages of S. frugiperda. Trichogramma chilonis Ishii and Telenomus remus Nixon egg parasitism rates were 15.81-23.87% and 5.44-8.78%, respectively. The larval parasitoids caused 9.18% parasitism of S. frugiperda larvae. Trichogramma chilonis appeared as a major natural enemy. These data provide an important baseline for the development of sustainable management strategies for S. frugiperda.
Six insecticides were evaluated for their toxicity against nymphs and adults of assassin bug, Sycanus collaris (Fab.) through contact and stomach mode. The studies revealed that emamectin benzoate (0.4g/L), chlorantraniliprole (0.25ml/L), flubendiamide (0.25 ml/L) and thiamethoxam (0.25 g/L) were considered as relatively safer insecticides for all the nymphal instars and adults of S. collaris. Fenazaquin (1.25ml/L) and quinalphos (2ml/L) caused higher mortality (85-100%) in all the stages of S. collaris. The higher mortality observed in nymphs and relatively lesser mortality rate of adults indicate that the application of the chemical should not be carried out immediately after the release of nymphal instars of S. collaris and adult releases would be ideal in Integrated Pest Management (IPM).
Eocanthecona furcellata (Wolff) is a potential native predator of lepidopteran larvae that can be easily reared under laboratory conditions and released in augmentative biocontrol for management of pests in various crops. For successful mass production of any predator cannibalism under crowded rearing conditions is the major limiting factor. In the present study, attempts were made to know the ideal population considered for group rearing with minimal or no cannibalism. It was recorded that the predator population of 5 to 25 on Corcyra cephalonica (S.) and Galleria mellonella L. and 5 to 30 on Samia cynthia ricini Boisd. and Spodoptera litura F. was feasible for group rearing with higher percent survival rate when reared in different group arenas. The survival percent was higher on hosts, C. cephalonica, G. mellonella, S. litura and recorded lower on S. cynthia ricini under group rearing condition.Â
The trap occupancy rate and colony development parameters of swarms of stingless bee, Tetragonula iridipennis in coconut shell traps was studied in the research farm of ICAR-National Bureau of Agricultural Insect Resources (NBAIR) Bengaluru, Yelahanka campus Karnataka, India. The trap occupancy rate by the stingless bees was 44.87% in a time period of 13.40 ± 4.38 days. New cells were constructed by the bees in 12.10 ± 2.13 days. The number of honey and pollen pots filled was 15.60 ± 3.92 and 6.61 ± 2.95, respectively. The brood cells were constructed 89.50 ± 6.07 days after acceptance of the shell traps with an average of 67.70 ± 20.83 brood cells per trap. The foragers preferred foraging for nectar, resin and pollen during the 15, 30 and 45 days after acceptance of the coconut shells for nesting. Coconut shell traps are easiest and economic way of trapping the swarming population of stingless bees.
Increased globalization and trade have made India a target for entry of many new alien insect pests.One such unintentional recent introduction is the cassava mealybug (CMB), Phenacoccus manihoti on cassava.Monitoring on the occurrence and damage potential of CMB on cassava was undertaken during 2020.Among the places surveyed, maximum damage score (4-5) and density of the mealybug (>1000/shoot tip) were recorded in Salem and Namakkal districts of Tamil Nadu and Thrissur district of Kerala.In the absence of effective native natural enemies and other methods of control, CMB might pose a major crisis to the cassava industry in India.The prospects of its suppression by classical biological control are quite vibrant and the initiative to import the parasitoid wasp, Anagyrus lopezi from Thailand and the Republic of Benin is already being taken by ICAR-NBAIR, Bengaluru, India.