35 



Many persons, no doubt, will object to applying so poisonous a 

 substance direct to the beads of the cabbages. This may be modi- 

 fied somewhat by surrounding the cabbage patch with a small strip 

 of some kind of plant other than the cabbages upon which the worms 

 feed; and as soon as the worms appear upon the plants in this 

 strip, to dust the latter with the poison. I contributed the following 

 article on this subject to the Iowa Homestead, and it appeared in 

 the issue of April 22, 1881. This article, after giving several rem- 

 edies, closes as follows : 



"Market-gardeners, who grow an acre or more of cabbages every 

 season, find that the worms are much more abundant on the plants 

 in the outer rows than they are on those which grow in the center 

 of the field. Upon this principle, if a few rows of some kind of 

 plant on which these worms feed, other than the cabbage, were 

 planted around the field, the butterflies — the parents of the worms — 

 would deposit their eggs upon these, instead of consigning them to 

 the cabbages. Besides the Cabbage, I have found these worms 

 feeding upon the Eadish, Eutabaga, Horse-radish and Mustard. The 

 last mentioned plant would probably be better than any of the oth- 

 ers for a border to a cabbage field ; the seed should be sown very 

 early and not too thickly, so that the plants will have attained a 

 considerable size when the cabbage plants are ready to be set out. 

 As soon as the worms appear upon the mustard the latter should 

 be sprinkled with Paris-green or London-purple and water, using 

 about two tablespoonfuls of the former, or one of the latter, to two 

 gallons of water ; and this should be continued throughout the 

 season. If Rutabagas are to be grown, these should be placed next 

 to the mustard, and if the worms appear upon them in destructive 

 numbers, they may be sprinkled with the poisonous solution witho.it 

 any injury to their roots. The early Cabbages should be placed 

 next to the Rutabagas, thus bringing the later sorts in the center 

 of the field. By this arrangement the worms will mostly be confined 

 to the Mustard and Rutabagas ; and if any find their way to the 

 early Cabbages, the latter, by their rapid growth, will be more 

 likely to withstand their attacks than the later kinds would. The 

 cabbage-field, if possible, should be perfectly square ; that is, it 

 should be as wide as it is long. The only drawback to growing 

 Mustard for this purpose is that when it once gets a foothold in the 

 soil it is sometimes very difficult to eradicate. In this locality the 

 Black Mustard (Brassica nigra) has become firmly established on a 

 few farms, and the owners find it almost impossible to eradicate it. 

 Whether the White Mustard (Brassica alba) has the same quality or 

 not, I can not say ; but if it has not, then it should be used instead 

 of the Black." 



The little parasite — Pteromalusjm parium, Linnaeus — very materially 

 assists us in lessening the numbers of these Cabbage Worms. 



It has been a disputed point with Entomologists as to whether 

 tins parasite deposits its eggs in the body of the worm or in the 

 chrysalis. The only recorded observation upon this subject that has 

 come to my notice is that made by Mr. Saunders, as detailed in 

 Prof. Thomas' Fourth Report.* This writer states that he saw the 



*Ninth Report of the State Entomologist, etc., p. 18. 



