कोबीवर्गीय

• Caterpillars web the leaves and bore into stem, stalk or leaf veins.

• They prevent head initiation causing multiple shoots or heads.

• Later stage bore into cabbage head.

Management:

• Collection and mechanical destruction of the larvae at early stage twice a week.

Chemical:

• For control of grown up larvae apply 5% malathion dust @ 37.5 kg/ha.

• Spray 250 ml of endosulfan 35EC in 150 litres of the water per ha.

• Application of 375 g carbaryl 50 WP in 150 litre of water.

• Eggs : 30-35 eggs along the underside of the leaf margins.

• Larvae : feed exposed in groups of 3-6 on the leaves during morning and evening. They remain hidden during the day time and when disturbed fall to the ground and finds death, seven stages and full grown in 16-35 days.

• Initially the larva nibbles leaves, later it feeds from the margins towards the midrib.

• The grubs cause numerous shot holes and even riddled the entire leaves by voracious feeding.

Management :

• Summer ploughing to destroy the pupa.

• Early sowing should be done.

• Maintain clean cultivation.

• Apply irrigation in seedling stage is very crucial for sawfly management because most of the larvae die due to drowning effect. Severe cold reduces pest load.

• Collection and destruction of grubs of saw fly in morning and evening

Chemical:

• Conserve Perilissus cingulator (parasitoids of the grubs), and the bacterium Serratia marcescens which infect the larvae of sawfly.

• Use of bitter gourd seed oil emulsion as on anti- feedant.

• Spray the crop with malathion 50 EC @ 1000 ml / ha quinolphos 25 EC @ 625ml / ha. All this should be applied in about  600 to 700 litres of water per ha.

• Only females are noticed in Maharashtra state. They reproduce parthenogenetically & single female produce 12-24 young ones (nymphs).

• Nymphs & adults suck the cell sap from lower leaves.

• Continuous feeding lead to general yellowing of leaves and subsequent drying.

• Attract the black fungus that hampers the photosynthetic activities of plant.

Management:

• Yellow sticky traps and yellow water pan traps catch aphids.

• Intercropping with Basil (Petite Bum) keeps numbers down.

• Apply good cultural practices such as weeding and using correct planting distances to promote vigorous plant growth.

Chemical:

• Apply Diazinon or Lambda cyhalothrin, this will provide a rapid kill of the pest, but there is a need to be repeated if the pest returns.

• Be warned that lambda cyhalothrin can also kill natural enemies such as ladybirds.

• Adult feed voraciously on leaves.

• By biting small numerous holes on foliage known as shot hole appearance.

• Grub feed on roots but do not cause severe damage

• Dusting of 10 % Carbaryl @ 20 Kg/ha.

• Spray 0.03 % Dimethoate @ 1.5 ml/lit.

• Larvae feed voraciously on leaves.

• By scraping the leaf surface.

• Larvae feed from margin of the leaves to inward direction of leaf lamina.

• Resulting the leaves intact the major vein alone

• Dusting of 10 % Carbaryl @ 20 Kg/ha.

• Spray 0.03 % Dimethoate @ 1.5 ml/lit.

• Papery white appearance.

• Irregular holes on the leaves.

• Skeletonization leaving only veins and petioles.

• Heavy defoliation.

• Spray tobacco decoction i.e. 250 g tobacco+ 30 g liquid soap+4 litre of water boiled for 30 minutes and diluted @ 1:4 parts of water.

• Spray spodoptera NPV (nuclear polyhedrosis virus) 250 LE/ha + 1% jaggery along with sticker (0.5 ml Beepol/litre) in the evening hours.

• Both nymphs and adult suck the cell sap from the leaves.

• Infested plant may finally dry up and died.