In 2005, Huanglongbing disease (HLB), also known as citrus greening, was discovered in Florida. The presumptive causal agent of this disease is the phloem-limited bacterium ‘Candidatus Liberibacter asiaticus’ (Las) which is spread by the Asian citrus psyllid (Diaphorina citri Kuwayama). Following the discovery of HLB, insecticide use for control of the vector has increased dramatically. One such insecticide is aldicarb, a soil-applied systemic carbamate insecticide that has been used in Florida citrus since the 1970's for both control of insect and mite pests and for its potential plant growth promoting benefits. The objective of this study was to determine the effects of soil-applications of aldicarb to citrus on the feeding behavior of D. citri, including whether this systemic insecticide disrupts feeding behaviors responsible for Las transmission. To achieve this goal, an electrical penetration graph monitor was used to examine D. citri feeding behavior when given a feeding access period of 12 h on aldicarb-treated and untreated citrus plants. Results showed no reduction in D. citri probing behaviors between treatments, and no insects died during recordings. Unexpectedly, at the cohort level, both phloem salivation and phloem ingestion were significantly longer on aldicarb-treated compared with untreated plants, suggesting that aldicarb application may increase the likelihood of Las transmission. Although registration of aldicarb for use in the U.S. has been discontinued for the last year, it has been reregistered for use in certain crops that may include citrus in the future. Thus, there is renewed importance in understanding the effects of aldicarb and other insecticides applied to suppress insect-transmitted diseases.