Cole-crop Insects 69 



Gkeen cabbage worm (Pontia rapw). — A velvety green 

 caterpillar about 1 in. long that eats holes in the leaves and 

 often burrows into the forming head. Control: The U. S. 

 Department of Agriculture recommends spraying the plants 

 with the following formula : water, 50 gals. ; soap, 4 lbs. ; 

 arsenate of lead (paste), 4 lbs., or powder, 2 lbs. In small 

 quantities : water, 1 gal. ; soap, 1 inch cube ; arsenate of lead 

 (paste), 1 oz., or powder, % oz. Since the cabbage head 

 grows from inside the plant there is no danger from poison- 

 ing. If the outer leaves are removed before cooking, spraying 

 is safe to within three weeks of harvest. If spraying is begun 

 early in the season there will be little damage from late broods 

 of worms. 



The poison may be applied in the form of a dust, using 

 1 part powdered arsenate of lead in 4 parts air-slaked 

 lime. In gardens the dust may be shaken on the plants by 

 means of a cheesecloth bag. Apply thinly while the dew is 

 on the leaves. 



When only a few plants are grown, hand-picking is often 

 the cheapest and easiest way to destroy the worms. In the 

 home garden, pyrethrum, hellebore and hot water (130° F.) 

 are convenient and useful remedies. 



Cabbage loopek (Autographa irassicw). — A green looping 

 catei'pillar, marked with longitudinal white stripes, about 1% 

 in. long when full-grown. The caterpillars eat out holes in the 

 leaves and often bore into the forming head. Control: The 

 caterpillars are difficult to poison as they dislike foliage coated 

 with an insecticide, and as they crawl about freely can easily 

 avoid the poison. The best results have been obtained by 

 spraying with paris green, 1 lb. in SO gals, of water to which the 

 resin-lime mixture has been added. Some growers lightly dust 

 with pure paris green with satisfactory results. 



Diamond-back moth (Phifella maciilipennis) . — Small pale 

 green caterpillars, about % in. long when full-grown, that eat 

 holes in the leaves from beneath. The injured part dies, turns 



