The Role of the Ant in the Biological Control of Homopterous Insects

Abstract

The ant as a factor in “facultative helotism” plays an important role in the biological conrrol of certain agricultural pests. This phenomenon was noted by Linnè in 1758 (Jones 1929; Wheeler 1910), when he observed that honeydew-producing insects such as aphids, mealybugs, and scale insects often functioned as “cows of the ants.”The importance of this function in the biological control of homopteroas insects lies in the fact that certain species are effectively controlled by their natural enemies when ants are absent, but not when ants are present. The ant, in gathering the honeydew supplied by such homopterous insects, tends more or less automatically to protect them from their natural enemies (Huber 1810). This apparently protective effect is not limited to the honeydew-producing species hut is often extended to other phytophagous forms such as the citrus red mite,Paratetranychus citri(McGregor), (Kenyon 1935; DeBach, Fleschner, and Dietrick 1951) and diaspid scale insects (Flanders 1945) when such forms happen to be within the area of ant activity.