Using Horticultural Oil, Pruning, and Acephate Banding to Reduce the First Generation of Crapemyrtle Aphid

The crapemyrtle aphid, Tinocallis kahawaluokalani (Kirkaldy) is the primary insect pest of crapemyrtle, Lagerstroemia spp. Aphids excrete honeydew that serves as a source of nutrients for various sooty mold fungi. Sooty molds form a black film on the leaves that reduces plant vigor and aesthetic quality. Reduction of the first generation of crapemyrtle aphids might delay production of sooty mold, reduce mid-season pesticide applications, and decrease pesticide injury to aphid predators. Two experiments were conducted to reduce the first generation of crapemyrtle aphids without using conventional contact pesticides. Both experiments utilized Lagerstroemia indica L. ‘Acoma’ as the host plant. To create infestations on the experimental plants, adult and immature crapemyrtle aphids were captured and placed on all crapemyrtles throughout July 1994. In the first experiment, treatments included a 2% and 4% (by vol) application of horticultural oil and pruning 33% of branch terminals. Treatments were initiated prior to aphid egg eclosion in April 1995. The second experiment was intiated after eclosion when a treatment of acephate: water (3: 1 by vol) slurry was painted on crapemyrtle trunks. Horticultural oil and acephate banding treatments reduced the number of first generation aphids compared to untreated controls.