Bio ecology and Management of Diamondback Moth Plutella xylostella L in Cabbage Brassica oleracea var capitata L

Abstract

newline Investigations on Bio-ecology and Management of Diamondback Moth, Plutella xylostella (L.) in Cabbage (Brassica oleracea var. capitata L.) was carried out at Horticulture Farm, Rajasthan College of Agriculture, Udaipur during Rabi, 2019- 20 and 2020-21 and the laboratory work was done in the Department of Entomology, Department of Molecular Biology and Biotechnology, Rajasthan College of Agriculture, Udaipur and in the Molecular Genetics Faculty of Aquaculture Research unit, DOR, MPUAT, Udaipur. newlineDuring both seasons, a markedly high population of diamondback moth larvae was recorded as 9.18 larvae/ plant during the 2nd week of March, 2020 and 10.15 larvae/plant during the 3rd week of March, 2021, respectively. Similarly, the peak populations of diamondback moth pupae were noticed during the 4th week of February (6.45 pupae/ plant) and the 1st week of March (7.08 pupae/ plant). DBM larval and pupal populations had a significant positive correlation with maximum atmospheric temperature and sunshine hours while a significant negative correlation was observed with mean relative humidity during both years. newlineThe aphidophagus natural enemies viz., coccinellids and syrphids were observed on cabbage during both the years. The peak population of coccinellids (1.13 and 1.35 adults/plant) were recorded during the 4th week of February and the 3rd week of February, respectively in both the years that correlated positively non-significant with mean temperature and positively significant with sunshine, while significant negative with relative humidity. Similarly, the monitoring on syrphid maggots populations showed that the peak activity of syrphids was during the 4th week of February (1.25 maggots/plant) and the 1st week of March (1.88 maggots/plant), respectively, during the respective seasons and positively significant with sunshine, newlinewhile significant negative with relative humidity. The spatial distribution parameters revealed that diamondback moth larval observations exhibited the clumped type of distribution