Insecticide purchases for 1981 will increase 10 to 15 percent over the last 2 years, when use was down because of light insect infestations. Herbicide use will rise about 5 percent. Supplies of nearly all pesticides should be ample because of unusually large carryover stocks. Prices may be up about 10 percent because of rising production and distribution costs. Rebuttable Presumption Against Registration (RPAR) proposed decisions were published by EPA for four pesticides in 1980: diallate, lindane, EDB, and strychnine.