As a result of an outbreak of long-tailed mealybug, Pseudococcus longispinus, on citrus in Los Angeles County, in 1933, the following hymenopterous parasites were introduced and established in southern California[long dash]Anarhopus sydneyensis, from Australia (1933), colonized in 1934; Tetracnemus peregrinus, from S. America (in the fall of 1934), colonized in 1935; Anagyrus fusciventris, from Hawaii (1936), colonized in 1936. A. sydneyensis and T. peregrinus appear to be effective in maintaining the populations of P. longispinus at low densities. A. jusciventris seems to be of little importance. Australia is apparently the native habitat of P. longispinus.