Studies on Seasonal Abundance of Diamondback Moth Plutella Xylostella (Lepidoptera: Yponomeutidae) On Cauliflower Crop

Studies on Seasonal Abundance of Diamondback MothPlutella Xylostella(Lepidoptera: Yponomeutidae) On Cauliflower Crop The studies on seasonal abundance of diamondback mothPlutella xylostellawere conducted in two years 2004-2005 and 2005-2006. Survey data of three localities of Aligarh district showed that initial infestation byP. xylostellaoccurred when the farmers started transplantation of cauliflower seedlings, the density ofP. xylostellaranged between 0.90 to 2.38 and 0.27 to 5.84 larvae and pupae/plant in I week of July, 2004 and 2005, respectively, and the rate of parasitization was quite low. Temperature and humidity recorded maximum and minimum i.e. 24.15° to 32.91°C and 68.60 to 91.30 percent, respectively. Population build up is usually observed in II to IV week of September.Cotesia plutellaewas found to be a dominant larval parasitoid while,Oomyzus sokolowskiiparasitized relatively few pupae ofP. xylostella.34.77°C significantly (p < 0.01) enhanced the population of DBM also on 8th September, 8th October, 2004 and 26th January, 2005. Rainfall negatively affected the DBM population in 2004-2005 and 2005-2006.