CABBAGE WORM

Pieris rapae

Description:

Adult: cabbage butterfly, white butterfly, tinged with yellow and having 3 or 4 black spots on it's wings which spread to about it' to nearly 2". It emerges with the coming of warm weather in spring.

Egg: Tiny, bullet shaped, ridged, pale to intense yellow in colour. Eggs usually laid on underside of leaves. Hatch in 7 or more days in spring.

Larva: velvety green caterpillars, each having slender orange stripe dorsally and paler broken stripes laterally. Has 5 pairs of prolegs. Attains length of It' - 12t' long then changes to pupa.

Pupa: Naked~grey, green or tan with angular projections suspended by a silk belt. After a week to 10 days it changes to adult.

There are 2 to 3 generations/year in North latitudes.

CONTROL	STAGE	DESCRIPTION, MIXTURES & AMOUNTS	EFFECT ON PEST
1. Cultural
2. Physical	Adult	Protective canopies of light-weight polyethylene to prevent infestation	Prevents adult from laying eggs on other cabbage leaves
	Larvae	Hand picking
3. Behavioural	Larvae	Anti metabolites (e.g.) imidazole with oil in water spray	Prevents them from eating
a) Repellants	Larvae	Southern wood and European wormwood
	Larvae	Sour milk or butter milk skim milk mixed with vinegar - spoon sour milk into centre of cabbage	Keeps larvae away
b) Companion plants	Larvae	Interplanting of mint, sage, rosemary, tansy, catnip, nasturtium, tomatoes and celery	Repels the larvae
c) friendly insects bacteria	Eggs	Trichogramma (wasp)	Feeds on egg
	Larvae	Yellow jacket hornets	Feeds on larvae
	Eggs	Braconid wasps	Feeds on egg
	Larvae	Bacillus thuringiensis (available as wettable dust under names of Thuricide and Biotrol). Be certain that the plants are thoroughly dusted so that larvae will be able to feed on dust.	Kill larvae
	Larvae	Black birds	Eat the larvae
4. Harmless pesticides/ others
a) sprinkling	Larvae	Salt and flour mixture : ½ cup of salt and 1 cup of flour. Mix the two and sprinkle over plant. Add 1 oz. Of mixture to the worst affected plants.	Larvae eats mixture, bloats up and falls dead.
	Larvae	A little salt is sprinkled from shaker-about twice as much as you would use in your food	Kills larvae
	Adults	Confectionery sugar	Desiccant
	Larvae	Rye flour - the finer the particles the better the adherence onto the insects body. One pint in enough for all plants in a small garden.	Cabbage moth and larvae with dough sticking to their wings, hands and bodies. Sun bakes dough hardens and kills them
b) Sprinkling	Larvae	Dry material (powdery) road dust, wood ash and cornmeal amount to cover the insect body	Block pores prevents respiration
c) Spray	Larvae	Water - use force but little water to avoid drenching the bed. Use ordinary spray or pressure tank.	To wash of younger cabbage worms from plants that would be injured by water.
	Larvae	Salt solution : one table spoon or 2 oz. Of salt mixed with a gallon of water	To control cabbage worms
	Larvae	Hot pepper solution : ground up several pods of hot pepper with equal amount of water, add ½ spoon of soap, powder to make the material adhere	Kills larvae
	Larvae	White hellebore with milk - the powder from rhizomes and rootlets of the hellebore plant is taken and mixed with milk and sprayed	Kills larvae
	Larvae	Pyrethrum : ground flowers of certain species of chrysanthemum contain insecticide. It is a preharvest spray because its breaks down rapidly in sunlight or strong artificial light.	Rapid "knock down" power
	Larvae	Derris - a tuba root	Stupefy the larvae
		Rotenone - made up roots of different species of trees especially lonchocerpus from L.Amer. Cube from Peru and timbo from Brazil	Slows down the rate of heart action and breathing
	Larvae	Ryania dust obtained from L.Amer. Shrub. Ryania native of Trinidad amounts used does not injure plant tissue.	It puts larvae in "flaccid paralysis" appetites wane, become incapable of normal activity and stop feeding
	Larvae	Nicotine : an antilarval spray. Boil 4 oz. Of non filter tip cigarettes of ½ lb. Of filter tips in a gallon of water for ½ hour. Strain clear brown liquid through nylon stocking	Kills larvae.

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