46 MASS. EXPERIMENT STATION BULLETIN 353 



Description. The adult female is a tiny buff-colored and gray-marked moth 

 with a wingspread of about ]/2 inch. 



The eggs are very tiny and are sugar-loaf-shaped, typical of the genus 

 Coleophora . 



The case for the caterpillar is slender, somewhat flattened at the rear, brown, 

 and about 3/8 inch long. The caterpillar has a light brown head, a dark brown 

 area just behind it on the back, and a hard, dark brown plate on the upper surface 

 at the rear end of the body. 



Elm Casebearers on Leaf. Actual size. 

 Courtesy, Conn. Agr. Expt. Station. 



Life History. The partly grown caterpillars pass the winter in a slender, 

 brown case attached to the limbs and branches of a tree. When the leaves appear 

 in the spring, the caterpillars migrate to them carrying their cases with them. 

 They eat in the leaf tissues a small, circular hole about the size of a pinhead and 

 then mine or eat out all the inner tissues they can reach without leaving the 

 case. In July they mature and pupate inside their cases which are firmly attached 

 to the leaves. The moths appear the latter part of July and lay their eggs. Upon 

 hatching, the young caterpillars first work as leaf miners, and probably, like some 

 closely related species, enter the leaf immediately under the egg. Soon, however, 

 they desert their mines and become case bearers. The\' feed for a time in the fall, 

 then migrate to the branches before the leaves fall. There is one generation a 

 year. 



Control. Lead arsenate, at the rate of 4 pounds to 100 gallons of water with 2 

 pounds of flour or 1 pound of calcium caseinate, applied in the spring when the 

 caterpillars begin to feed, is the treatment usually recommended for this insect. 

 A contact spray which has proved to be satisfactory against a related species is 

 sometimes recommended for the control of this insect and should be applied when 

 the tiny, young caterpillars first desert the leaves and become casebearers. The 

 spray consists of 1 pint of 40 percent nicotine sulfate plus 4 pounds of soap in 

 100 gallons of water. 



Britton, W. E., and Friend, R. B. Conn. Agr. Exp. Sta. Bui. 369:288-289. 1935. 

 Felt, E. P. N. Y. State Mus. Mem. 8(1) :167-168. 1905. 

 McDaniel, E. I. Mich. Agr. Exp. Sta. Spec. Bui. 243:42. 1933. 



