Relation between ants and aphids in a citrus orchard

Abstract

*[In a survey of 9-year-old Satsuma orange trees conducted at 15-day intervals from May to December 1971 in an orchard in Kyushu, 2 peaks were noted in the density of the populations of Toxoptera citricida (Kirk.) & Aphis spiraecola Patch, in mid-May & in early October, during a flush of growth. During the 10-day periods when the aphids were most abundant, the temperature was about 20 deg C & the relative humidity 78%. Of 5 species of ants observed, Pristomyrmex pungens Mayr was dominant for most of these peak periods, & it is assumed that this ant interferes with the activity of predators.]