THE MONTHLY BULLETIN. 



197 



Other plants attacked are wild mustard, wild radish, nasturtium, mig- 

 nonette and sweet alyssum. 



Control.— The larvie, working as they do into the heads of the 

 cabbages, make control methods practically imptis.sible after they 

 have once begun. Young plants may well be protected by arsenical 

 sprays which are applied with safety until the heads are half-grown. 

 Prof. L. Bruner claims that cornmeal dusted on the cabbages causes 

 the worms to leave. Clean culture should be practiced and no cabbage 

 or host plants allowed to grow during the interval between crops unless 

 they are freely sprayed with strong solutions of arsenical sprays. 



Natural Enemies. — Internal parasites, working upon the chrysalids, 

 are important factors in the control of the pest. In this State the small 

 parasite (Pteromalus puparum) is quite widely distributed and is bred 

 and sent to all parts of the State by the State Insectary. In the 

 Eastern States a chalcid {Apanteles glomeratus) does excellent work 

 in killing off the caterpillars, but this has not been established in this 

 State. A bug {Phymata wolffii) preys upon the butterflies, which they 

 capture on flowers while the wasp {rolistes paUipes) destroys large 

 numbers of the worms. 



THE CELERY OR PARSLEY CATERPILLAR. 



Papilio t>()li/xrn<:s Fab. (Family Fapilionidfe). 

 {Pdjiilio asierids Fab.) , 



(Fig. 184.) 



General Appearance. — The most evident forms of this insect are the 

 feeding caterpillars, which are indeed very .striking. The youngest of 



Fig. 184. — Caterpillar and chrysalis of the parsley butterfly {PaiJilio 

 polyxenes Fab.). (Original.) 



these are noticeably darker with yellow spots. When full grown they 

 are yellowish green with distinct black bands and dots on the bodies. 

 If disturbed they throw out a forked, orange-colored scent organ behind 



