This study analyzed the impact of weather variables on insect pest dynamics and their diversity in the radish ecosystem through field experiments conducted for two years at a locality in the eastern Himalayas. The relationship with weather variables was studied with six different dates of sowing, and diversity was assessed using standard indices. Various organic management options were also evaluated. Results revealed that temperature had a positive impact, whereas relative humidity and rainfall negatively affected the population of insect pests. The radish ecosystem harbors diverse insect species, including natural enemies, with higher species richness (4.8–5.2) and lower year-to-year variability. Organic management strategies such as neem oil, Beauveria bassiana, and Metarhizium robertsii demonstrated good efficacy against flea beetles without compromising yield, resulting in 39.76%, 39.39%, and 38.71% pest reduction over control, respectively. These biopesticides also recorded less than half to one-fourth reduction in natural predators like coccinellids compared to cypermethrin, a chemical pesticide (74%). The study suggests that, under projected climate change with higher temperatures, pest populations are assumed to increase. Considering the insect diversity of the eastern Himalayas, organic management strategies will be an adaptation strategy to conserve biodiversity while ensuring environment-friendly pest management.

Background: Ricebean [Vigna umbellata (Thunb.) Ohwi and Ohashi] is an important food legume grown in Nagaland, India. It is a versatile underutilized pulse crop grown as a dry pulse and also used as green manure and fodder. Insect pests are one of the major constraints encountered and the pulse beetle, [Callosobruchus chinensis (L.)] is an important pest that causes considerable damage to Vigna seeds. This experiment was carried out to determine the basis of resistance among different ricebean cultivars against pulse beetle which will help in development of resistant varieties. Methods: A laboratory experiment was conducted during January-June of 2019 and 2020 where 16 ricebean cultivars were screened against pulse beetle. The biological parameters of the pest on different cultivars were studied. Correlation between biological parameters of C. chinensis and physico-chemical parameters in different ricebean cultivars was studied. Result: Significant difference was observed in terms of the biological parameters of the pest and the physico-chemical parameters of seeds. The seed size and seed index have significant correlation with the biological parameters of pulse beetle. Cultivars with higher protein and starch content were more susceptible while cultivars with higher phenol and tannin content were less susceptible. Based on the growth index, the following three cultivars viz., Rhüjo, Akixi Anila and Manyhü Rhi were found to be moderately resistant.

Background: Broccoli is a nutrient-rich cole crop gaining importance in India due to its high dietary and economic value. However, its productivity is severely constrained by the infestation of several insect pests, particularly aphids and lepidopteran borers, which cause considerable yield losses.
Aims: To study the diversity and seasonal incidence of insect pests infesting broccoli (Brassica oleracea var. italica) and to determine their relationship with key abiotic factors. Study Design: The experiment was conducted using a Randomized Block Design (RBD) with three replications under natural field conditions. Place and Duration of Study: The study was carried out at Ummulong, West Jaintia Hills, Meghalaya, during Rabi season from December 2020 to March 2021. Methodology: Broccoli was grown following standard agronomic practices in plots of 2.2 m × 2.2 m. Five plants per plot were randomly selected and tagged for observations. Weekly monitoring of insect pests was conducted from 7 days after transplanting until harvest. Different sampling techniques were employed based on pest feeding habits. Meteorological data (temperature, relative humidity, and rainfall) were recorded, and correlation and regression analysis were performed to assess their influence on pest incidence. Results: A total of 12 insect pest species belonging to five orders and ten families were recorded. Among them, the green peach aphid (Myzus persicae) and Indian cabbage white butterfly (Pieris canidia) were identified as major pests. The peak population of M. persicae (34.17 aphids per plant) was observed during the last week of December, while P. canidia reached its maximum (2.57 larvae per plant) in the third week of January. Correlation analysis revealed a significant negative relationship between pest population and both maximum and minimum temperatures, whereas relative humidity and rainfall showed non-significant relation. Conclusion: The study demonstrated that temperature is a critical factor influencing the incidence of major insect pests in broccoli, with lower temperatures favoring pest buildup. These findings emphasize the importance of weather-based pest forecasting for timely and effective implementation of integrated pest management strategies to reduce yield losses.