▁million ▁was ▁spent ▁ann ually ▁to ▁control ▁them ; ▁but ▁ 1 9 8 9 ' s ▁attack ▁was ▁estimated ▁to ▁have ▁cost ▁$ 6 0 ▁million ▁in ▁er adic ation ▁efforts , ▁making ▁ 1 9 8 9 ▁the ▁second - most ▁expensive ▁year ▁in ▁the ▁state ' s ▁program . ▁It ▁is ▁not ▁clear ▁whether ▁the ▁$ 6 0 ▁million ▁was ▁the ▁total ▁cost , ▁or ▁only ▁represented ▁California ' s ▁half ▁of ▁a ▁possible ▁$ 1 2 0 ▁million ▁cost , ▁as ▁half ▁the ▁costs ▁were ▁bor ne ▁by ▁the ▁federal ▁Department ▁of ▁Agricult ure . ▁ ▁Cla im ▁of ▁responsibility ▁ ▁In ▁December ▁ 1 9 8 9 , ▁a ▁two - page ▁letter ▁address ing ▁Los ▁Angeles ▁Mayor ▁Tom ▁Brad ley ▁was ▁sent ▁to ▁the ▁Los ▁Angeles ▁Times ▁and ▁F res no ▁Be e ▁ost ens ibly ▁from ▁an ▁" ec ot error ist ▁organization " ▁calling ▁itself ▁" The ▁Bre ed ers ". ▁The ▁Bre ed ers ▁claimed ▁that ▁it ▁was ▁responsible ▁for ▁the ▁summer ▁release ▁of ▁the ▁med f lies ▁as ▁ret ali ation ▁for ▁the ▁environmental ▁damage ▁caused ▁by ▁the ▁Mal ath ion ▁aer ial ▁sp ray ing ▁by ▁the ▁state . ▁It ▁also ▁threatened ▁to ▁expand ▁its ▁med fly ▁inf est ation ▁into ▁the ▁San ▁Jo aqu in ▁Valley . ▁The ▁letters ▁claimed ▁that ▁officials ▁would ▁have ▁noticed ▁an ▁u pt ick ▁in ▁med fly ▁numbers ▁around ▁March ▁ 1 9 8 9 . ▁The ▁group ▁promised ▁to ▁make ▁the ▁aer ial ▁sp ray