2 BULLETIN 265, TJ. S. ^EiPAETMENT OF AGRICULTUEE. 



In the fall of 1914 the writer's attention was called to a number of 

 apples which had been perforated in ione or more places, the holes 

 being round, about 2 millimeters in diameter, and similar in appear- 

 ance to those caused by an apple stem or by the apple falling on 

 alfalfa stubble. These holes, however, were evidently the work of an 

 insect. On cutting open these apples, one or more bright-green 

 worms were found in each, in the burrows extending from the entrance 

 holes. These larvae were not feeding but were lying dormant, as 

 though intending to pass the winter here. They appeared to be 

 the larvae of a sawfly, and, on looking up the literature, it was found 

 that the larvae of the dock false-worm were known to bore into apples 

 occasionally. Adults were secured the following spring and definitely 

 determined by Mr. S. A. Rohwer as Ametastegia glabrata Fallen. A 

 visit on September 30, 1914, to the orchard from which these apples 

 came, which is situated along the Entiat River, a tributary of the 

 Columbia River in north-central Washington, showed that the injury 

 from these larvae was of some importance, about 2 per cent of the 

 early apples, Jonathans and King Davids, being injured. This 

 amounted to considerably more than the injury caused by the codling 

 moth, which is as yet uncommon in this valley. Dr. A. L. Quaint- 

 ance, entomologist in charge of Deciduous Fruit Insect Investiga- 

 tions, suggested that a study of the insect be made, and accordingly a 

 number of infested apples were kept over the winter. Early in the 

 spring the orchard was again visited, and several hundred hibernating 

 larvae, which had burrowed into the alfalfa stubble on the ground, 

 were collected. With this abundant material a study of the life 

 history and habits of this insect was begun, and the results form the 

 subject of this paper. The writer is indebted to Mr. S. A. Rohwer, 

 of the Bureau of Entomology, for suggestions and information 

 regarding this species, and to Mr. Frank E. Knapp, of Entiat, Wash., 

 for permission to carry on observations and control experiments in 



his orchard. 



HISTORY. 



The dock false-worm has been known for more than a hundred 

 years, the adult having been originally described in Sweden by Fallen 

 (1), in 1808, as Tenihredo glabrata. It was subsequently described 

 under several names and placed in several genera in Europe, as shown 

 in the synonymy below. The larva appears to have been first recog- 

 nized by Kaltenbach (6) in Germany in 1859. The adult insect was 

 originally described in America in 1862, by Norton (8), as Taxomis 

 nigrisoma, and this name has been generally used in this country, 

 although the name Strongylogaster abnormis was also applied to the 

 species by Provancher (22) in 1885. The larva was first noted here by 

 Jack in 1893. In 'a recent paper by Rohwer (37), it is considered 

 that the European and American species are identical, and therefore, 



