8 BULLETIN 966, U. S. DEPARTMENT OF AGRICULTURE. 



HISTORY IN NORTH AMERICA. 



The species was described by Hiibner from Europe in 1792 (1) and 

 must have been introduced into this country, probably with its favor- 

 ite food plant, at an early date, since it came under the observation 

 of Harris in 1841 (5, p. 322). In Harris's notebooks appear the 

 following memoranda : 



Oct. 30 and Nov. 1, 1841. Found on leaves of horse-radish. 



They eat large holes out of leaves, leaving finally only the veins untouched. 

 They live beneath the leaves, stretched out by the sides of the midrib. They 

 creep regularly, not haltingly, and move pretty fast. When alarmed or dis- 

 turbed they curl quickly, and lose their hold, and fall to the ground. . . . 

 Found the same on turnip leaves, Oct. 20, 1844. their ravages very considerable. 



This account includes a description and a reproduction of a sketch 

 of the larva, which are omitted here. AValker's description appeared 

 in 1859 (.^, p. 756) and Avas based on specimens from the United 

 States and Nova Scotia. 



An account of this insect by William Buckler (4) appeared in 

 1882. Not knowing the insect's food plants, but judging that it 

 would live on Cruciferae, he placed the eggs on different plants. In 

 confinement the larvae fed freely on Barbarea vulgaris^ Sinapis ar- 

 vensis, and C ardamine amara. Larvae molted three times, as fol- 

 lows : The first molt occurred August 8 to 10, the second August 17 

 and 18, and the third August 24 to 27. By September 29 all were 

 full-fed and were inclosed in cocoons of earth. The moths began to 

 issue June 20 of the following year, continuing emergence up to 

 July 27. Buckler describes the egg, stating that it hatched in 8 days, 

 the newly hatched larva, the different molts, and the cocoon. 



Many years after Harris's first account. Dr. James Fletcher (^, p. 

 231) furnished the second account, and writes in 1904 that occasional 

 reports had been received at different times for 10 years of attack 

 on cabbage and turnip in the maritime Provinces of Canada. 

 The caterpillars were described as congregating on the crowns of 

 turnips and eating cabbages into the roots as well as consuming the 

 leaves. Whole fields of cabbage and turnip were destroyed at Cape 

 Breton Island. The larvae were described as starting under the 

 leaves just out of the ground and mining their way up to the head, 

 tunneling it hollow. Injury was also reported to cabbage in 1903 

 at Old Chelsea, Quebec, Canada, and an original description of the 

 larva was included. 



In 1918 a popular account of this species was published by Messrs. 

 Crosby and Leonard {11^ p. 19-20). 



FOOD PLANTS. 



Harris recorded Evergestis strcmiinalis on horse-radish and turnip, 

 and Fletcher noted attack on these plants and on cabbage in Canada. 



