. Bulletin of the Department of Agriculture. Agriculture; Agriculture. 1 BULLETIN No. 438 Contribution from the Bureau of Entomology L. O. HOWARD, Chief. Washington, D. C. PROFESSIONAL PAPER December 11,1916 THE PEAR LEAF-WORM. By R. L. NouGARET, Entomological Assistant, and W. M. Davidson and E. J. New- COMEB, Scientific Assistants, Deciduous Fruit Insect Investigatix}ns. CONTENTS. Page. Introduction 1 History and distribution 1 Possible origin 2 Character and extent of injury 3 Description and habits 4 Biology 9 Natural control 17 Remedial measures 18 Summary 22 Bibliography 23 INTRODUC
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. 1 BULLETIN No. 438 Contribution from the Bureau of Entomology L. O. HOWARD, Chief. Washington, D. C. PROFESSIONAL PAPER December 11,1916 THE PEAR LEAF-WORM. By R. L. NouGARET, Entomological Assistant, and W. M. Davidson and E. J. New- COMEB, Scientific Assistants, Deciduous Fruit Insect Investigatix}ns. CONTENTS. Page. Introduction 1 History and distribution 1 Possible origin 2 Character and extent of injury 3 Description and habits 4 Biology 9 Natural control 17 Remedial measures 18 Summary 22 Bibliography 23 INTRODUCTION. The pear leaf-worm, more scientifically termed the pear sawfly (GymnonycJius californicus Marlatt), is an hymenopterous insect belonging to the family Nematidse and to the subfamily Nematinse. For several years it has been noted as a pest on pear trees on the Pacific coast. The observations and experiments recorded herein were made in California by Messrs. R. L. Nougaret and W. M. David- son, during the years 1911 to 1914, inclusive, and in the State of Washington by Mr. E. J. Newcomer, during the seasons 1914 and 1915. The injury is caused almost entirely by the feeding of the green wormhke larva and is confined to the foliage, resulting in partial defohation. In the localities in which it occurs the insect is quite abundant. Occasionally it becomes a pest of serious consequence, and under favor- able conditions it might cause widespread damage. HISTORY AND DISTRIBUTION. The p(!ar leaf-worm was describ(;d from 1 female coUectod at Brockport, N. Y., and 10 females taken near Sacramento, Cal,, by Note.—This bulletin Is of interest to pear growers generally, but especially to those of the Pociflo coast. 67170*—Bull. 4:«—18 1. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States. Dept. of
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