26 SOME INSECTS INJURIOUS TO TRUCK CROPS. 
foliage of these plants, but Glover states that they sometimes feed 
upon the petals of the flowers of cotton, although doing little harm 
to the general crop. 
THE INSECT'S LIFE HISTORY. 
Our knowledge of the life history of this species is somewhat 
incomplete. The repeated rearing of moths in early spring and the 
occurrence of larvae in the latter part of June in Massachusetts as 
recorded by Smith, as also in the District of Columbia and elseAvhere 
as late as October, noted by the writer and others, show at least two 
generations in the Northern States, while the record of the occur- 
rence of the moths in March in Texas (by Belfrage) would indi- 
cate that in the Gulf States there may be an additional generation. 
It would seem practically impossible for larvae hatching from eggs 
deposited in early spring to require until late October to attain 
maturity, hence the natural inference of two generations for a 
climate like the District of Columbia. The cranberry growers of 
Massachusetts claim two generations for that State, one appearing 
as larvae in June and early July, the other in the latter part of 
August. 
The eggs are unknown, and the periods of egg and larva have 
not been ascertained, but the pupal condition has been observed to 
be passed, for the first generation, in from 11 to 14 days, while the 
over-wintering pupa consumes five or six months in the District of 
Columbia, a shorter time farther south, and a longer time nortliAvard. 
The date of the appearance in the North of the first moths has 
not been learned positively nor the natural time of emergence of the 
first new generation of moths. 
NATURAL ENEMIES. 
Doctor Smith 7 has stated that the larvae of this spanworm are 
checked by parasites, but that in some localities almost every year 
they become numerous enough to be destructive. In some years, 
however, in the cranberry bogs of New Jersey they are not seen at 
all, showing great scarcity, clue probably in part, at least, to natural 
causes. Only one parasite for this species is known, namely, Ex- 
orista boarmice Coq., a tachina fly reared at this Department from 
Cotuit and other localities in Massachusetts several years ago. 
REMEDIES. 
This species is not difficult to control on asparagus or other truck 
crops. As it feeds in free exposure on the foliage, spraying with 
Paris green or arsenate of lead will destroy it, and when either of 
these insecticides is used for the asparagus beetles it will kill all of 
the spanworms which may be present. The Paris green may be 
