The Asian citrus leafminer (Lepidoptera: Gracillariidae) (CLM) and the Asian citrus psyllid (Hemiptera: Psyllidae) (ACP) are two important insect pests that have invaded Texas in the last two decades. They feed preferentially on new flush growth of citrus plants, thus affecting plant growth. Damage caused by CLM can be substantial as leaf infestation can reduce photosynthetic potential. While the direct damage of ACP is relatively small, its vectoring of the bacterium pathogen of the deadly citrus greening disease makes it a pest of economic importance. We investigated the potential of the systemic neonicotinoid imidacloprid in the control of these insect pests in a five year old ‘Rio Red’ grapefruit orchard. Trees were treated with imidacloprid (Admire® Pro) as soil drench application at the rate of 14 oz/acre. Pre-treatment and weekly post-treatment assessments of insect pest numbers and damage levels were conducted on new flush growth for twelve weeks. In addition, levels of imidacloprid in leaf tissue were quantified using Enzyme-Linked Immunosorbent Assay (ELISA). Both insect numbers of ACP and damage levels of CLM on new flushes were significantly reduced (91% and 80%, respectively). A negative and noteworthy correlation was obtained between imidacloprid titers in leaf tissue and pest density per citrus flush. Soil applied imidacloprid has a great potential to provide control of ACP and CLM.