Distribution and Control of the Cabbage Seedpod Weevil in California

Abstract

The life history of Ceutorhynchus asstmilis is briefly discussed. Counties having the highest infestations and commercial seed losses in 1950 were San Mateo, Santa Cruz, and Santa Clara. Adjacent counties had relatively high infestations but have little commercial seed production. The Salinas valley in Monterey County, had a light infestation. Indications are that after building up here it may spread to the Lompoc valley farther south. The north central valleys of Calif. have a very light to moderate and variable infestation in several counties. Possibly the cabbage seedpod weevil will build up sufficiently to cause economic losses to the turnip and mustard seed grown in parts of this area. In n. central coastal Calif. technical benzene hexachloride was the most effective insecticide tested. Lindane, aldrin and dieldrin gave satisfactory exptl. control. Dieldrin was inferior in the control of the cabbage aphid. 3 spp. of parasites reared from coastal Calif. seedpods in 1950 were killed or repelled by the insecticides used in the exptl. plots; 2 additional parasites were found in central Calif. in 1951. Benzene hexachloride caused no apparent decrease of fertilization or phytotoxicity, but it may build up serious soil residues. Lindane was indicated as the most desirable and the safest material to date.