The Role of Natural Enemies and Biopesticides for Sustainable Management of Major Insect Pests of Legumes

Pulses are the important components of a healthy diet and take an important place in the traditional diets throughout the World (Malaguti et al. 2014). pulses are damaged by a large number of insect species, both under field conditions and in storage (Clement et al. 2000). Among legume insect pests, Helicoverpa armigera is the single largest yield shrinking factor in food legumes, causes an estimated loss of US$317 million in pigeonpea and$328 million in chickpea (ICRISAT 1992). Worldwide, it causes an estimated loss of over $2 billion annually, despite over$1 billion value of insecticides used to control H. armigera (Sharma 2005). Another pod borer Maruca vitrata causes loss to the tune of US$30 million annually (Saxena et al. 2002). Pigeonpea yield losses due to pod borer are 25–70 fly is second most important pest of pigeonpea in northern and central India, and cause 10 - 50 reported to cause 5 - 25 can induce up to 58 et al. 1994) and annually$2.4 billion estimated losses in yield (Song et al. 2006, Tilmon et al. 2011). Legume flower thrips (LFT), Mylothris sjostedti Trybom in cowpea V. unguiculata in tropical Africa causes yield losses ranging from 20% to 100% (Karungi et al. 2000)

Frequency of Cry1Ac and Cry2Ab resistance alleles in pink bollworm, Pectinophora gossypiella Saunders from Andhra Pradesh, India

Since 2002, transgenic crops that produce Cry1Ac and Cry2Ab toxins have been used in India to control bollworms. From 2002 to 2009, Bt-cotton effectively controlled the pink bollworm (PBW). However, since 2009 numerous studies have reported high survival of PBW on Bt-cotton expressing Cry1Ac and Cry2Ab toxins, indicating reduced susceptibility to Cry toxins expressed in Bt-cotton. In the current study, we attempted to estimate the frequency of resistance alleles to Cry1Ac and Cry2Ab toxins in a field collected population of pink bollworms from Andhra Pradesh. Resistance allele frequency was estimated using an F2 screen methodology for the first time after 17 years of Bt-cotton cultivation. Our study finds that the allele frequency for Cry1Ac is 0.082 and for Cry2Ab is 0.054, with a detection probability of greater than 97%. In our survey conducted in 2018–19 and 2019–20, we also noticed high survival and damage by PBW on Bt-cotton expressing Cry1Ac and Cry2Ab. Our survey report reveals, > 30% flower damage, > 90% green boll damage and > 80% locule damage by PBW on Bt-cotton expressing Cry1Ac and Cry2Ab toxins

Development of Temporal Model for Forecasting of Helicoverpa armigera (Noctuidae: Lepidopetra) Using Arima and Artificial Neural Networks

Helicoverpa armigera (Hübner) (Noctuidae: Lepidopetra) is a polyphagous pest of major crops grown in India. To prevent the damage caused by H. armigera farmers rely heavily on insecticides of diverse groups on a regular basis which is not a benign practice, environmentally and economically. To provide more efficient and accurate information on timely application of insecticides, this research was aimed to develop a forecast model to predict population dynamics of pod borer using Autoregressive Integrated Moving Average (ARIMA) and Artificial Neural Networks (ANN). The data used in this study were collected from the randomly installed sex pheromone traps at International Crops Research Institute for the Semi-arid Tropics (ICRISAT), Patancheru, Hyderabad. Several ARIMA (p, d, q) (P, D, Q) and ANN models were developed using the historical trap catch data. ARIMA model (1,0,1), (1,0,2) with minimal BIC, RMSE, MAPE, MAE, and MASE values and higher R2 value (0.53) was selected as the best ARIMA fit model, and neural network (7-30-1) was found to be the best fit to predict the catches of male moths of pod borer from September 2021 to August 2023. A comparative analysis performed between the ARIMA and ANN, shows that the ANN based on feed forward neural networks is best suited for effective pest prediction. With the developed ARIMA model, it would be easier to predict H. armigera adult population dynamics round the year and timely intervention of control measures can be followed by appropriate decision-making schedule for insecticide application

Frequency of resistance alleles to Cry1Ac toxin from cotton bollworm, Helicoverpa armigera (Hübner) collected from Bt-cotton growing areas of Telangana state of India

Transgenic cotton expressing Bacillus thuringiensis (Bt) cry1Ac and cry2Ab toxin genes is widely cultivated to manage bollworm complex in India. Cotton bollworm Helicoverpa armigera (Hübner) is one of the most serious of this complex. It is likely to evolve resistance to Cry toxins in view of continual selection pressure due to extensive cultivation of Bt cotton. Monitoring susceptibility of cotton bollworm using conventional bioassays is reported to have shown its increasing tolerance to Cry1Ac over the years. We report using an F2 screen Cry1Ac resistance allele frequencies of 0.050 (95% CI 0.022–0.076) and 0.056 (95% CI 0.035–0.075) in the insect populations collected from pigeon pea grown alongside Bt cotton in the respective years of 2016 and 2017 in the Telangana state of India. Compared to our earlier studies for 2013 and 2014, resistance allele frequency to Cry1Ac in the cotton bollworm in the following two years remains unchanged. The significance of these results is discussed in the context of non-Bt host crops acting as refuge for cotton bollworm for ensuring sustainable resistance management

Agroecological transformation for sustainable food systems : Insight on France-CGIAR research

This 26th dossier d’Agropolis is devoted to research and partnerships in agroecology. The French Commission for International Agricultural Research (CRAI) and Agropolis International, on behalf of CIRAD, INRAE and IRD and in partnership with CGIAR, has produced this new issue in the ‘Les dossiers d’Agropolis international’ series devoted to agroecology. This publication has been produced within the framework of the Action Plan signed by CGIAR and the French government on February 4th 2021 to strengthen French collaboration with CGIAR, where agroecology is highlighted as one of the three key priorities (alongside climate change, nutrition and food systems)