UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 265 



Contribution from the Bureau of Entomology 

 L. O. HOWARD, Chief 



Washington, D. C. 



PROFESSIONAL PAPER 



December 29, 1916 



THE DOCK FALSE- WORM: AN APPLE PEST 



Scientific Assistant, Deciduous Fruit Insect investigations. 



Introduction 



History 



Distribution 



Food plants 



Character of injury to apples. 

 Economic importance 



CONTENTS. 



Page. 



1 

 2 



Page. 



Description 



Life history and habits . 



Natural enemies • 



Remedial measures 



Summary 



Bibliography 



INTRODUCTION. 



The dock false-worm is the larva of an allantine sawfly (Ametastegia 

 glabrata Fallen) which may be called the dock sawfly. It has long 

 been known, both in Europe and America, as an enemy of dock, 

 sorrel, and knotweed, all common and sometimes troublesome plants 

 which are to be found growing in moist places everywhere. Its 

 acquired habit of boring into mature apples on the tree, to hibernate, 

 thereby destroying their market value, brings it into prominence as 

 an economic pest and has been noted by several observers in this 

 country. Fletcher, in 1903 (30, 31) 1 and 1904 (33), reported finding 

 the larva of a sawfly, which proved to be this species, boring into apples 

 in Ontario in rather large numbers, and R. L. Webster (36) mentions 

 the presence of these green worms in apples from New York, in 1908. 

 Prof. A. L. Melander, of the Washington Experiment Station, in a letter 

 to the Bureau of Entomology, under date of November 1, 1912, 

 reports having known of the fruit-burrowing habit of this larva in 

 British Columbia and since 1903 in Washington, particularly at 

 Lynden, Whatcom County, where the injury amounted to about 10 

 per cent. 



1 Figures in parentheses refer to Bibliography, p. 38-39. 

 5G815 — Bull. 2G5— 16 1 



