750 



KEPORT UNITED STATES GEOLOGICAL SURVEY. 



crow-quill. It changes in September, under some board or stone, to a 

 chrysalis, suspended by a thread spun over the back as shown at Fig. 

 20, ft. It is of a pale flesh-brown color, freckled with 

 black. It winters in this state, the butterfly appearing 

 in Massachusetts early in May. 



The native cabbage-butterfly {Pieris irrotodice^ Figs. 

 21-23) is but slightly injurious to the cabbage in the 

 Southern and Western States. 



Remedies. — It does not appear to have been very de- 

 structive in Europe, but, like other introduced species, 

 it suddenly becomes a fearful scourge in a new country. 

 The best remedies are evidently hand-picking, when the 

 caterpillars can be seen, and the capture of the butter- 

 flies by means of a light gauze-net mounted on a wire 

 ring a foot in diameter, and attached to a short pole. 

 Affected cabbage-heads should be carefully examined, ^jg 

 and if much infested by worms, be burned; for, if they 

 are suffered to lie about the garden after being pulled 

 up, the caterpillars will attack the other plants. 



— Enropean 

 Cabbage Butterfly. 

 a, caterpillar, b, 

 chrysalis. 



Fig. 21.— Native Cabbage Butterfly, 

 male. 



Fig. 22. — Native Cabbage 

 female. 



Butterfly, 



Mr. C. S. Minot, in an article 

 entitled " Cabbage-butterflies," 

 in the American Entomologist, 

 vol. ii, strouglj" recommends de- 

 stroying the chrj'salis, which 

 may be found under chips, 

 boards, stones, etc., and advises 

 that boards, raised two inches 

 above the surface of the ground, 

 be placed among the plants to 

 attract the caterpillars when 

 about to change to a chrysalis. 



Riley recommends drenching 

 the plants with a wash of cres- 

 ylic soap, for this and other noxious cabbage-insects. As those chrys- 

 alids which are infested by the chalcid flies are readily distinguished 

 from the healthy ones by their livid and diseased appearance, they can 

 be selected and preserved or left alone, and thus the parasites can be 

 bied. 



The Toronto Globe recommends hot water to be applied to cabbages 

 that are infested with the Pieris rapcc, sprinkled on from a fine rose wa- 

 tering-can. The water may be boiling-hot when put into the can, but it 

 will not be too hot when it reaches the leaves. The thick fleshy nature 



Fig. 23. — Native Cabbage Butterfly 

 pillar, b, cbrysalis. 



a, cater- 



