The host mediated effect of climate change on biotic potential of cowpea aphid, Aphis craccivora (Koch.)

Climate change will alter the photochemistry of crops, especially the C3 plants. Cowpea (Vigna unguiculata L.) being an annual, photo-insensitive C3 legume is benefitted by altered climate. Any changes in the nutritional quality of host will certainly affect its herbivore. In this view, study was conducted on crop-pest interaction i.e., to know the impact of climate change on the growth and development of cowpea alone and in presence of associated sucking pest aphid, Aphis craccivora (Koch) during kharif 2019-20. The crop was raised in Open Top Chambers previously set with different climatic treatments. Observations on change in plant growth and phytochemistry along with its effect on herbivore aphid was studied. The results revealed that elevated CO2 and temperature influenced the crop positively in terms of growth and also have registered higher concentrations of leaf pigments, carbon and ‘C’ based metabolites. In contrast, lower concentrations of flavonoids, ‘N’ based compounds were recorded which ultimately altered the C: N ratio in plant system. The obtruded phytochemistry of cowpea under elevated treatments resulted in decreased development (12.73 ±0.07 days) and survival fitness of aphids, wherein increased fecundity (34.56 ±0.18days) and population density (73.43/ top three leaves) was noticed when compared to ambient treatments.