Influence of CO₂and Temperature on Metabolism and Development ofHelicoverpa armigera(Noctuidae: Lepidoptera)

Abstract

Climate change will have a major bearing on survival and development of insects as a result of increase in CO2 and temperature. Therefore, we studied the direct effects of CO2 and temperature on larval development and metabolism in cotton bollworm, Helicoverpa armigera (Hübner). The larvae were reared under a range of CO2 (350, 550, and 750 ppm) and temperature (15, 25, 35, and 45°C) regimes on artificial diet. Elevated CO2 negatively affected the larval survival, larval weight, larval period, pupation, and adult emergence, but showed a positive effect on pupal weight, pupal period, and fecundity. Increase in temperature exhibited a negative effect on larval survival, larval period, pupal weights, and pupal period, but a positive effect on larval growth. Pupation and adult emergence were optimum at 25°C. Elevated CO2 and temperature increased food consumption and metabolism of larvae by enhancing the activity of midgut proteases, carbohydrases (amylase and cellulase), and mitochondrial enzymes and therefore may cause more damage to crop production. Elevated CO2 and global warming will affect insect growth and development, which will change the interactions between the insect pests and their crop hosts. Therefore, there is need to gain an understanding of these interactions to develop strategies for mitigating the effects of climate change.

Effects of elevated CO2 on the fitness and potential population damage of Helicoverpa armigera based on two-sex life table

“…The objectives of the study were to (1) determine the population parameters and consumption rate of H . armigera in response to elevated levels of CO 2 , and compare our life table data with previous life table studies 14–16 ; and (2) predict the fitness of and potential damage caused by H . armigera populations resulting from anticipated future increases in CO 2 concentrations.…”

“…Akbar et al . 16 found that CO 2 enrichment and increased temperature increased the consumption and metabolism of H . armigera fed an artificial diet by increasing protease activity and carbohydrates in the midgut.…”

“…Akbar et al . 16 suggested that increased CO 2 could adversely affected the larval survival, larval duration and larval weight of H . armigera fed an artificial diet, whereas pupal weight and individual fecundity would be increased.…”

Constraints to Vegetable Production Resulting from Pest and Diseases Induced by Climate Change and Globalization: A Review

“…The feeding behaviour of the larvae was affected by elevated carbon dioxide. Results showed that elevated carbon dioxide contributed to the increase of food consumption and metabolism of the larvae and this gives an indication that Helicoverpa amigera larvae may cause more damage under elevated carbon dioxide (Akbar et al, 2016). Herlicoverpa amigera is one of the major global insect pest that feed on brassicas and its damage can lead to high yield loss (Machekano et al, 2017).…”

“…These pressures from insect pests can either be in a form migration to new areas or they can be in a form of new introduction in areas (Ziska et al, 2016), and these often underlies their distribution and abundance, hence the level of damage they cause to crops (Mazzi & Dion, 2012). Elevated concentrations of carbon dioxide also affect insect pest growth and their development and this often results in changes in the interaction between insect pests and their crop host (Akbar et al, 2016;Elad & Pertot, 2014).…”