TY - JOUR AU - Clausen, C.P. TI - Biological control: Natural enemies of aphid in California sought in European, Mid-East countries JF - California Agriculture JO - Calif Agr Y1 - 1955/07/01 VL - 9 IS - 7 SP - 4 EP - 4 PB - University of California Agriculture and Nature Resources SN - 0008-0845 UR - http://www.ucanr.edu/sites/calagjournal/archive/?article=ca.v009n07p4b AB - Field observations on the yellow clover aphid were made in southern California during the past year to determine the status of the predators that attack the aphid and the presence or absence of internal parasites. No internal parasites were found.