none The relationship between yellow sticky trap catches of Pholetesor (= Apanteles ) ornigis (Weed) and its emergence during the first two of its three yearly emergence periods was examined using four trap locations in five commercial apple orchards in Norfolk County, Ont., during 1984 and 1985. The yellow traps were more sensitive to male than to female first emergence during the first summer emergence period. The number of male parasites caught on traps placed within the tree in the peripheral zone gave the best indication of peak male emergence during the first summer emergence period. The most accurate indication of peak female emergence was given by the number of female parasites caught on traps placed within or below the tree in the interior zone of the orchard.