103 
early cutting of cabbage and destruction of the cabbage stumps 
in the immediate vicinity—is probably the most important eco¬ 
nomic measure. In fact it is best, when possible, to grow no 
cabbage, cauliflower, rape, or turnips near greenhouses in which 
stock or sweet alyssum is to be grown. 
Infested plants should be thoroly sprayed with arsenate of 
lead at the rate of i pound to 18 gallons of water*, especial care 
being taken to reach the under surface of the leaves. It is hardly 
necessary to say that the sooner the spraying is done the more 
thoroly will the worms be eradicated. Usually the plants are 
small when first attacked, and arsenate of lead is recommended 
for them; but if the plants are in bloom, a decoction of fresh 
pyrethrum, or insect powder, one ounce to two gallons of water, 
should be used. In addition to measures against the larvae, large 
numbers of the moths may be destroyed by the use of light traps, 
described on page 87. In regard to the use of lights, Mr. Hild 
wrote me as follows: “In the latter part of September we placed 
candles in the greenhouses at night alongside of a pie-plate con¬ 
taining a little kerosene oil. This seemed to be the most effective 
remedy we used. In a week we caught thousands of the moths, 
but the nights suddenly got cool and the moths were dormant, 
so this method was not then so successful.” 
Where only a few plants are infested, hand-picking is an effec¬ 
tive remedy; but in commercial greenhouses this method is tedious 
and expensive.. 
The Alternanthera Worm 
Hymenia perspcctalis Hiibn. 
(Spolodca perspcctalis ) 
During the year 19TO a number of complaints* were re¬ 
ceived from florists, stating that a small green worm—which 
proved in one case to be the larva of a moth ( Hymenia per¬ 
spectalis) —was eating the foliage of the variegated border plant 
(Alternanthera) . This larva feeds on 'the leaves, and if numer¬ 
ous enough to attract attention usually defoliates the plant re¬ 
peatedly (Fig. 16) as new shoots and leaves put forth, thus 
ruining it for ornamental purposes, necessarily weakening it, and 
not infrequently killing it. Certain garden varieties are more 
susceptible to injury than others. For example, A. paronychioides 
major is most generally attacked, and next in favor are rosea 
nana, versicolor, and anrea nana , the order of mention indicating 
their relative susceptibility to this injury. The last, anrea nana, 
*In only one case did we obtain specimens for the identification of the 
species. 
