An artificial diet and a rearing procedure for the polyphagous pest, Spodoptera frugiperda, were developed to facilitate its culturing under laboratory conditions [27 ± 1°C, 65 ± 5% relative humidity and a photoperiod of 14:10 (L:D) h] throughout the year. The efficiency of the diet was assessed through a comparative study with the natural host of the pest, maize. The biological, reproductive and population parameters of the pest on artificial diet were superior, especially the enhanced mean fecundity of 1796 per female which was more than that of the insect reared on its natural host. The meridic diet gave a higher mean pupal weight (0.217 g/pupa) than the natural diet (0.188 g/pupa). About 81.8% of neonates completed their developmental cycle on artificial diet and emerged as healthy adults, compared to only 57.5% normal adult emergence on the natural diet. On observation, there were 3678 and 3551 eupyrene sperm bundles in the adults emerged from larvae reared on artificial diet and natural diet, respectively. The net reproductive rate () for adults reared on artificial diet was 945.26, it being 703.7 for adults reared on a natural diet. With a sex ratio of 0.55, the biotic potential of S. frugiperda reared on artificial diet was 5.104 × 10²⁸, which is more than that of natural diet (5.740 × 10²⁶). The fertility life table constructed in the present study can play a significant role in predicting population dynamics, which will further help in developing an effective integrated pest management and the developed meridic diet with rearing procedure will be helpful in insecticide resistance monitoring programmes for this folivorous pest.

Insects being poikilotherms rely on external temperatures to regulate their body heat that making them vulnerable to climate change as temperature fluctuations directly impact their growth, reproduction and survival as well as control their metabolic and physiological processes. Many insect species are in danger as global temperatures are increasing since they cannot physiologically adapt themselves for long exposure to high temperatures. This vulnerability is especially pronounced in species that have not evolved mechanisms to endure extreme heat, leading to potential population decline and disruptions in ecosystems Understanding the mechanisms of how insects manage heat stress is crucial for predicting their behaviour and biology in the scenario of a changing climate. This review delves into the genetic basis of thermoregulation in insects, exploring how genes influence their ability to cope with heat stress and regulate their internal body temperature in hot conditions through mechanisms such as heat shock proteins, metabolic adjustments, and behavioural changes. It also highlights gaps in current research and suggests future studies, emphasizing the need for comprehensive investigations into the molecular, genetic, and ecological aspects of thermoregulation. Advanced insights into insect thermoregulation will enhance our understanding of insect population dynamics and facilitate the development of effective pest management strategies, contributing to climate-resilient agriculture amidst the challenges posed by a changing climate.

Sex ratios in insect populations are critical in shaping their reproductive dynamics, genetic diversity, and ecological interactions. While genetic factors often determine sex, abiotic factors have emerged as important influencers of sex ratios in insects. The influence of abiotic factors on sex ratios in insects is of scientific interest and holds practical implications for insect conservation and management. As environmental conditions change due to global warming, understanding how sex ratios respond to these changes can aid in predicting population dynamics and designing effective conservation strategies for biocontrol agents as well as the management of insect pests. Abiotic stressors, including fluctuations in temperature, humidity variations, altitude & latitude, nutrition and chemical exposure have been shown to disrupt the precise balance of hormonal and genetic cues governing sex determination in insects. Insects being ectothermic, body temperature depends on the surrounding environmental conditions and are highly vulnerable to the change in climate. This review explores the intricate relationship between abiotic stress and sex determination mechanisms in insects, highlighting recent advances in our understanding of how stress-induced alterations especially environment in hormone signaling, gene expression, and epigenetic modifications can lead to skewed sex ratios and developmental anomalies. Regardless of the advances in this area, notable research gaps are still present. Future studies on the multiple abiotic factors and their synergistic effects will give a more detailed study of insect populations, and their ecosystems. This comprehensive review delves into the multifaceted interactions between abiotic factors and sex differentiation in insects. In conclusion, the abiotic factors especially temperature are indeed game changers in the insect sex ratio dynamics.