TY - JOUR AU - Sibbett, G. Steven AU - Bettiga, Larry J. AU - Bailey, Marion TI - Walnut aphid becoming a costly midsummer pest JF - California Agriculture JO - Calif Agr Y1 - 1982/05/01 VL - 36 IS - 5 SP - 21 EP - 22 PB - University of California Agriculture and Nature Resources SN - 0008-0845 UR - http://www.ucanr.edu/sites/calagjournal/archive/?article=ca.v036n05p21 AB - Controls for codling moth suppress aphid parasite, allowing undisturbed population growth.