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 

 jiassed in the pupal condition, and the moths appear in May and June. 

 The first eggs hatch in a moderate temperature in six da3^s, 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. 



MefJiods 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 CATERPILLAR. 



{Leucarcfia acrxa Dm.) 



Several forms of hairy caterpillars, such as the yellow bear [Spilo- 

 soma virgmica)^ of similar appearance and habits, are commonly found 

 on sugar beet. One of these, known as the salt-marsh caterpillar 



e c 



Fig. 41. — Leticarctia acrxa: «, female moth ; 6, 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 acrsea 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 arid in gardens. 



