Cauliflower crop destroyed | Plant diseases | Commercial Hydroponics farming

Posting a picture would have helped. My experience has been that once the leaves are eaten up it is too late.

It is very difficult to recover from such attacks. As usual prevention is better than cure. Other than the usual organic stuff like neem oil, garlic, chilli sprays I cannot think of any non organic remedy. GG.in sells a organic pesticide called Biofarm pe-fu-mi. I have used it but I cannot say how effective it is. If you are OK with chemical treatments then you can try foliar spray of 2ml of Chloropyriphos per 1 L. You will have to wait for around 21 days since the last application before you harvest for consumption as it is a highly toxic systemic insecticide. (I once used 5 ml in 20 Lts of hydroponic NS to get rid of the pests on a bottlegourd plant. In less than 3 hours the whole 15 ft plant died.)

I have been having good results with pheromone traps (Pheromonechemicals.in) and regular preventive neem oil spray.

If you can get hold of the bugs take pictures of it and post. The guy from Pheromone Chemicals will visit the Jan 26th Horticultural show at Peoples Plaza, Necklace road if it is held this year. You can show him the pictures and ask for the right trap and lure.