The Problem of Celery Leaf-Tyer Control

Abstract

The celery leaf-tyer ( Phlyctaenia rubigalis Hubn.) was first reported as a serious pest in 1909 and caused such heavy losses in southern California that much of the acreage was abandoned. The leaf-tyer is most numerous and active, and develops more rapidly in the warm weather of the summer and fall. This is at the time when the main celery crop is young and growing vigorously. Lead arsenate, applied at the rate of 3 pounds to 100 gallons of water or Bordeaux mixture, and not more than 100 gallons of spray to an acre, gave satisfactory control. Several applications may be necessary at intervals of two weeks or more. These applications, being made on young, growing celery, are not likely to leave a residue of poison on the plants at harvest time. There is a considerable acreage of early celery, practically mature when the leaf-tyer is most abundant and is thus subject to heavy infestation. The protection of this celery in such a way that no poison remains on the plant at harvest time is a difficult problem. A close watch must be kept for the first infestations when the celery should be carefully sprayed, using adequate machinery, applying a fine misty spray to both sides of the leaves. The early applications are the most important, as they serve to reduce damage from later generations. All spraying must cease at least a month prior to harvesting.