1 190 



Rural School Leaflet 



its legs and is entirely free from the shell of the chrysalis, it rests quietly 

 while its wings gradually expand and dry and then it flies away. 



The whole life cycle, from the laying of the egg to the appearance of 

 the butterfly, is passed in twenty-two days to five weeks. In New York 

 the cabbage butterfly finds time during the summer season for at least 

 three broods. Farther south, where the summers are longer, there must 

 be four or five generations each season. 



The winter is passed in the chrysalis stage. The last chrysalides formed 

 in the fall, instead of bursting open and giving forth a butterfly, remain 

 unchanged until warm weather of the following spring. 



Natural enemies. — The green caterpillars are subject to the attacks 

 of certain tiny, wasp-like, parasitic insects that kill many of them and aid 



greatly in controlling this cabbage 

 pest. Very often one of the dead 

 green caterpillars is found attached to 

 % a cabbage leaf and partially covered 

 sfUjM by many small white objects, usually 

 % considered eggs by those who do not 

 know. As a matter of fact, these are 

 the cocoons of the tiny parasites that 

 have lived within the body of the cater- 

 pillar and killed it. When the para- 

 sites are full-grown they leave the 



A dead cabbage worm, with a cluster of caterpillar and spin their small white 

 cocoons oj the parasites that killed it ,, , . , c m ■,■ ■> 



J y cocoons on the outside, from which 



the small, dark-colored, wasp-like parasites emerge in a few days ready 



to parasitize other cabbage worms. Whenever a lot of these white 



cocoons are seen about a green caterpillar they should not be destroyed, 



but should be allowed to remain undisturbed so that the parasites may 



emerge to work on other "worms." 



Methods of control. — This cabbage pest is best controlled by spraying 

 the plants with one of the arsenicals, paris green or arsenate of lead. There 

 is no danger in spraying cabbages with a poison up to the time they are 

 half-grown, and even later. A cabbage is only a gigantic bud and grows 

 from the inside outward as does any other bud. The outside leaves 

 never fold up about the head, hence there is little danger of enclosing 

 the poison within the cabbage. 



If paris green is used it should be applied at the rate of 1 pound to 1 50 

 gallons of water, or sifted on dry, in the latter case being thoroughly 

 mixed with flour at the rate of 1 pound to 2 5 pounds of flour. This should 

 be applied in the morning while the dew is yet on the cabbage leaves. 



Arsenate of lead may be applied at the rate of 2\ pounds to 50 gallons 

 of water. 



