Impact of Ultraviolet Radiation with Alpha-terthienyl on the Aphids Pea Aphid (Acyrothosiphon pisum) and Mustard Aphid (Lipaphis erysimi)

Due to ozone depletion, the potential threat of rising solar UV radiation levels at the Earth's surface has led to demand for worldwide measurement of solar UV radiation. UV is electromagnetic radiation with a wavelength ranging from 200 nm - 400 nm and constitutes about 10% of the light output of sun. It is the most photochemically reactive wavelength of solar radiation and important critical abiotic stressor for organisms, particularly in their early stages of life. UV radiation directly regulates insect life processes and indirectly changes in insect biochemistry and morphogenesis.

In this study, measurement of solar UV-B was performed in the Haridwar and Tehri Garhwal, Uttarakhand with the help of radiometer having UV-B sensor. Artificial UV-B provided with UV-B lamp. Mortality rate, Protein content and GSH level were observed in mustard and pea crop aphids species after exposure to solar and artificial UV-B irradiation separately and with alpha-terthienyl photosensitizer.

The data of measurement of UV-B showed that the maximum intensity of UV-B was found in during month of June and minimum in the month of January. Mortality rate of aphids that artificial UV-B radiation with alpha-terthienyl shows a highly toxic effect on aphids population diversity and dispersal. Protein and GSH level decreased in all groups compared to control. Maximum reduction in protein and GSH level was found in after treatment of artificial UV-B with alpha-terthienyl. Exposure of artificial UV-B radiation with alpha-terthienyl shows stunted growth, morphological changes, low reproduction and high mortality in aphids. Artificial UV-B was found to be more toxic than solar UV-B. Mustard aphid (Lipaphis erysimi) was found to be more sensitive than pea aphid (Acyrthosiphon pisum). Climate change and increase in UV-B levels affect aphid development and population growth.