Rice water weevil is the most econo

Rice water weevil is the most economically damaging of the invertebrate pests found in California. Root pruning by larvae is the major cause of reduced yields. Plants with damaged roots may become stunted and lose yield through reduction of tillers and panicles or because maturity is delayed. Reduced tillering and slower growth also allow weeds to become better established. The heaviest infestations and most serious damage can be expected to occur between late May and July within 15 to 20 feet of the margins of the fields and levees, where weevils are concentrated; moderate damage can occur in areas 20 to 35 feet from levees.