In-lab bovine blood and cattle field efficacy testing were conducted to determine effects of LongRange 5% eprinomectin extended-release injectable parasiticide on survival and fertility of Anopheles spp. mosquitoes. Mosquitoes were fed spiked blood in-lab and on cattle post-injection in the field. In-lab rates between 0.001 and 0.8 l LongRange/ml of bovine blood were fed to mosquitoes, and cattle in the field were injected with single and double the label rate (1 ml LongRange per 50 kg). Mosquitoes that fed on single and double dose-treated cattle did not show mortality differing significantly following the majority of feedings on control cattle. Plasma analysis at the time of each feeding did not reveal detectable eprinomectin levels following day 7 post-treatment of cattle. LongRange is not a promising addition to the insecticidal zooprophylactic approach to mosquito management for vectors with high tolerance to macrocyclic lactones.