The lesser peach borer (Synanthedon pictipes G. and R.) was first described in 1868 by Grote and Robinson, but was not considered a pest of much economic importance until 1906, when Quaintance reported that it had caused considerable injury to peach trees in Georgia. Since that time it has been regarded as an important peach insect, and during recent years it has caused much damage to some peach orchards. The insect has a decided preference for peach trees, which are its favored host, although other known food plants are plums and cherries (both cultivated and wild), the black-knot fungus (Plowrightia morbosa) on plum and cherry, juneberry, beach plum, and chestnut. The only control for this insect has been to cut the larvae out of their burrows with a knife, but as hand-worming is unsatisfactory, and since the trees are seldom killed by the attacks of this insect, even this measure has not been enforced. Consequently, heavy infestations, especially in old orchards, are not uncommon. The absence of an effective and practical remedy for the control of this important peach insect attracted the senior writer's interest in the problem in 1924 when observations and experiments were started. This circular gives the results of experiments conducted at Fort Valley, Ga., during the three years 1928 to 1930, inclusive.