THE LOCUST TWIG BORER. 359 



2. The locust- twig borer. 



Ecdytolopha insiticiana Zell. 



Order Lepidoptera ; family Tortricid^. 



Boring in the twigs of locust, sometimes causing a tliickened growth of the stem 

 for the distance of from 1 to 3 inches, a pale whitish larva with brownish head, 

 which cuts its way out when full grown, descending to the ground and transforming 

 into a yellowish-brown pupa in curled leaves upon the surface, and finally emerging 

 a dark-brown moth with dirty pinkish-white on the outer portion of the fore- wings. 



We have observed this larva at work at Brunswick, Me., August 20 

 to 22, the galls being numerous, but copy Professor Oouistock's account 

 of the insect, premising that the swelling or galls we observed are about 

 20mm iQi^g and 7 to 8°^"" thick. They are quite sticky on the surface, 

 with a hole at the lower end for the exit of the castings. It is interest- 

 ing to observe how the body of a boring Tortricid is modified to adapt 

 itself to a lignivorous existence. This is seen in the development of 

 rugose semi-chitinous or fleshy patches on the exposed dorsal area of 

 the segments. Professor Gorastock's account is as follows ; 



During the latter part of September the terminal shoots and twigs of several 

 varieties of locust {Robinia pseudacacia vars. crispa, tortuosa, and inermis) growing on 

 the department grounds were observed to have an abnormal thickened growth from 

 1 to 3 inches in length, and enlarging the stem at this place to nearly twice the 

 normal size, the enlargement being quite uneven and irregular. An examination of 

 some of these diseased stems disclosed the fact that a lepidopterous larva was boring 

 along the central part of the stem and feeding upon the tissues. This larva when 

 full grown is about half an inch in length, of a yellowish color, somewhat darker on 

 the dorsal line. Head dark brown ; thoracic plate light honey yellow. On the 1st 

 of October these larvae left the stem through holes which they had cut out to the 

 surface, and descended to the ground, where they transformed to pupse among the 

 dry and curled leaves which had fallen, and in which they spun thin but tough 

 silken cocoons. Sometimes they crawled between a fallen leaf and the ground, when 

 the cocoon adhered to the leaf on one side and was thickly covered with grains of 

 sand on the other. 



The first moth emerged October 17, and others from the 20th to the 27tb. An 

 examination of a large number of shoots proves that this insect deserts its burrow 

 to transform on the ground. 



Some of the shoots were badly infested ; ten places where larvae were at work 

 were counted in one of them, and the whitish excrements hung in clusters from the 

 holes, which were almost always between two of the thorns, where the egg had 

 probably been deposited. These shoots, however, were not enlarged. 



This species was described under the above name by Prof. P. C. Zeller, of Stettin, 

 Germany, from specimens received of Mr. Burgess, who took them in Massachusetts 

 in June and July. Professor Fernald informs us that he has received them from Mr. 

 Morrison taken in Colorado. 



Remedies. — The only remedies we can suggest are to cut ofl' the 

 infected twigs before the escape of the larvie and burn them. If for 

 any reason this has not been done, it would be well to collect carefully 

 all the leaves beneath the infested trees and burn them to destroy the 

 insects while in the pupal state. This should be done, however, after 



