Callage. 269 



Europe, has become so widespread and serious that many cab- 

 bage crops are annually ruined by it. Gardeners are only too 

 familiar with the mature and the larval forms to require com- 

 plete descriptions for the identification of the insect. The 

 adult is a white butterfly having the outer fore corner of the 

 front wings marked with black. In addition to this the male 

 has one black spot near the center of the front wings, while the 

 female has two. The insects pass the winter in the chrysalis 

 state, and in spring the mature forms appear. The female lays 

 her eggs, which are small and of a yellow color, upon the leaves 

 of cabbages and related plants ; in a few days the eggs hatch, 

 producing small green worms that feed upon the foliage of 

 the plants upon which they were laid. These worms become 

 full grown in about two weeks, when they seek some sheltered 

 place in which they turn to pupne. In from one to two weeks 

 a new crop of butterflies may be seen, and these in turn con- 

 tinue to propagate the species. Several broods appear each year. 



Treatment. This pest is most easily destroyed when it is in 

 the larval stage. It may then be treated in two general ways. 

 As the larvre eat the foliage they may be poisoned very easily 

 by applying hellebore or some form of arsenic. The latter, 

 however, must be used only upon young plants, otherwise there 

 is danger of poisoning the human consumer. Hellebore may 

 be used quite freely at all times, since it loses its strength on 

 exposure to air. The other method of destroying the insects is 

 to apply poisons which penetrate the soft covering of their 

 bodies. For this purpose kerosene emulsion may by success- 

 fully employed, but as in the case of the arsenites, only young- 

 plants should be treated in this manner. For heading cabbages, 

 it is safer to use some form of pyrethrum. Some prefer the use 

 of hot water to all other remedies ; it is clean, does not injure 

 the plants if properly applied, and it destroys the worms. It 

 is unpleasant to handle, however, and its use has not generally 

 been favored. Particular care should be taken to kill the first 

 brood, whatever the remedy selected, for if this brood is exter- 

 minated, later ones will have small chances of appearing. All 

 applications should be repeated as often as seems to be 

 necessary. 



Harlequin Cabbage-bug (Murgantia histrionica, Hahn). De- 

 scription. This southern insect is gradually extending north- 



