Oils as uv protectants of Beauveria bassiana conidia and bioefficacy against Lipaphis erysimi (Kalt) Devi Kirti1, Joshi Neelam2,*, Sangha K. S.2 1Department of Microbiology, Punjab Agricultural University, Ludhiana, 141001 2Department of Entomology *Corresponding author Email: neelamjoshi01@pau.edu
Online published on 23 October, 2018. Abstract The management of insect pests by entomopathogenic fungus depends upon maintaining sustenance of fungal isolates to abiotic stress. The present study was conducted to evaluate four plant based oils viz. soybean, rice bran, sunflower and mustard oil as UV protectants with conidia of Beauveria bassiana (Balsamo) and their pathogenicity against third instar nymphs of mustard aphid Lipaphis erysimi (Kalt). Beauveria bassiana supplemented with soybean oil recorded maximum colony forming units (9.47×103conidia/ml) followed by sunflower (8.09×103conidia/ml), rice bran (4.14×103conidia/ml) and mustard oil (3.23×103conidia/ml) after 60 sec of UV exposure. When supplemented with soybean and sunflower oil and evaluated against third instar nymphs of L. erysimi it resulted in 67.18 and 66.14% mortality, though at par with each other but significantly better than untreated control (61.92%). However, when oil supplemented conidial suspension of B. bassiana was exposed to UV (305 nm) for 20 sec, the mortality decreased to 61.20, 59.48 and 54.61% in soybean, sunflower and untreated control (conidial suspension without oil), respectively. Among all Beauveria isolates, the native isolate B. bassiana (F10) and an isolate of commercial formulation Mycojaal® resulted in maximum mortality of nymphs of mustard aphid and were most pathogenic. Top Keywords Beauveria bassiana, conidia, bioassay, Lipaphis erysimi, 3rd instar nymphs, mortality, soybean, rice bran, sunflower, mustard oils, UV radiation, protection. Top |