Impact of temperature and carbon dioxide on food consumption and nutritional indices of Plutella Xylostella Linnaeus (Lepidoptera: Plutellidae) on cauliflower

The study investigated the impact of elevated temperature and carbon dioxide (CO₂) levels on the food consumption and nutritional indices of Plutella xylostella Linnaeus (Lepidoptera: Plutellidae) on cauliflower. Insect populations from Ludhiana and Malerkotla were subjected to six different combinations of temperature and CO₂ levels (25:11ºC and 28:14ºC at 350, 400, 450 ppm CO₂ concentrations). Food consumption, consumption index, relative growth rate, approximate digestibility and efficiency of conversion of ingested food of third instar larvae of Ludhiana population increased significantly from 5.36, 0.92, 0.47, 50.96, 45.83 to 5.59, 1.20, 0.53, 55.29, 50.71, respectively with an increase in CO₂ levels from 350 ppm to 450 ppm and from 5.27, 0.84, 0.46, 49.10, 43.01 to 5.66, 1.27, 0.54, 56.56, 53.66 respectively with an increase in temperature from 25:11ºC and 28:14ºC. Food consumption, CI, RGR, AD and ECI also increased significantly in Malerkotla population, with an increase in temperature and CO₂ levels. Similarly, in fourth instar larvae of both populations, food consumption, CI, RGR, AD and ECI increased significantly with the increase in temperature and CO₂ levels. Thus, elevated temperature and CO₂ and their interaction influence the food consumption and nutritional indices of P. xylostella which could ultimately result in increased crop damage and reduced yields. Therefore, further research on the impact of climate change on insect pests and their interactions with crops is crucial for developing adaptive and integrated pest management strategies to ensure agricultural resilience and food security in the face of changing environmental conditions.