An outbreak of diamondback moth, Plutella xylostella occurred in agroclimatic conditions of Aligarh, western part of Uttar Pradesh, India during September to first fortnight of October, 2006 on cauliflower. The infestation increases gradually from first fortnight of August where an average of 28–234 larvae and pupae/plant was monitored in sampled areas at a temperature ranging 33.20–21.3°C with relative humidity of 83.5–68.0% and rainfall during this fortnight was 7l.00 mm. Parasitized larvae and pupae were also collected from fields in first fortnight of August and the rate of emergence of Cotesia plutellae was 0.192.99%. The intensity of infestation reached to 669–895.5 larvae and pupae/plant in mid September that resulted in complete skeletonisation of leaves. Rationally, it is a case of total loss (100% yield loss) caused by DBM at an average temperature of 21.80–35.70°C, 57.4–83.90% relative humidity and 97.6 mm rainfall with a low rate of parasitization (7.0–7.30%) in mid September.
Diamondback moth, Plutella xylostella, parasite, cauliflower, temperature, relative humidity
