TY - JOUR AU - Retan, Arthur H. AU - Post, George R. AU - Davis, Clarence AU - Michelbacher, A. E. TI - Filbertworm control trials: Two new insecticides tested on Payne, Franquette and Hartley walnuts in two experimental orchards in northern California JF - California Agriculture JO - Calif Agr Y1 - 1958/04/01 VL - 12 IS - 4 SP - 10 EP - 11 PB - University of California Agriculture and Nature Resources SN - 0008-0845 UR - http://www.ucanr.edu/sites/calagjournal/archive/?article=ca.v012n04p10 AB - The intensity of the filbertworm infestation of walnuts in northern California in 1957 was less than in the peak year of 1954, but it marked the fourth straight year that the filbertworm has presented a problem. Based on past history the 1957 attack was surprising because observations have indicated that the pest would not continue at a highly destructive level over a period of several years.