Studies on biology and predation efficiency of Ischiodon scutellaris (Fabricius) on cowpea aphid, Aphis craccivora Koch under elevated CO2 and temperature conditions

Abstract

Investigation to assess impact of elevated CO2 and temperature on biology and predation efficiency of a syrphid, I. scutellaris on cowpea aphid, A. craccivora was carried out during Rabi season of 2018 and 2019 at College of Agriculture, Shivamogga, Karnataka by using the research facility of open top chambers (OTCs). The pooled data results revealed that among the different treatments of elevated CO2 and elevated temperature, the treatment eCO2 (650±25 ppm) + etemp (+2 °C) recorded minimum total larval period with 9.59±0.19 days as compared to the ambient/ lab condition which recorded maximum total larval period (11.89±0.29 days). The total larval consumption was maximum in eCO2 @ 700±25 ppm treatment with 469.85±10.05 aphids as compared to the ambient condition (449.55±5.94 aphids) and it was minimum in ambient CO2 (390±25 ppm) + elevated temperature (+2 °C) (398.65±9.83 aphids). The treatment eCO2 (650±25 ppm) + etemp (+2 °C) treatment recorded minimum total developmental period with 24.51±0.41 days as compared to the ambient condition which recorded the maximum total developmental period (28.57±0.52 days).