43 
some in the second generation, which usually appears in September. 
In addition to the -plants that have been mentioned as furnishing- food 
for the zebra caterpillar are cauliflower, turnip, beans, carrot, potato, 
corn, currant, cranberry, willow, roses, and others. The winter is 
passed in the pupal condition, and the moths appear in May and June. 
The first eggs hatch in a moderate temperature in six days, and the 
larval period is about five weeks. The pupal period is very long, 
lasting, as observed by the writer, sixty-seven days, making in all a 
period of one hundred and ten days from the time the eggs were laid 
until the moths appeared, late in August. This species can endure a 
considerable amount of cold, but is very susceptible to parasitic attack, 
and to a less extent to fungous diseases. 
Methods of control. — The caterpillars when first hatched are gregari- 
ous, hence easily discovered at this time and destroyed by hand or by 
poisons. They yield readily to sprays of arsenicals, but these are not 
necessary in ordinary cases of attack. ♦ 
THE SALT-MARSH CATERPILL.AB,. 
{Leucarctla acrxa Dru.) 
Several forms of hairy caterpillars, such as the yellow bear {Spilo- 
soma virginica)^ of similar appearance and habits, are commonly found 
on sugar beet. One of these, known as the salt-marsh caterpillar 
Fig. 41.— Leucarctla acrsea: a, female moth; b, half-grown larva; c, mature larva, lateral view, d, head 
of same, front view; e, egg mass— all slightly enlarged except d, more enlarged (original. Division 
of Entomology). 
{Leiicarctia acrxa Dru.), from its ravages early in the past century 
upon forage crops grown in the salt marshes of New England, is occa- 
sionally troublesome in beet and corn fields and in gardens. 
