Alexander Henry Haliday was an Irish entomologist. He is primarily known for his work on Hymenoptera, Diptera, and Thysanoptera, but worked on all insect orders and on many aspects of entomology.

Thrips are minute, slender insects with fringed wings and unique asymmetrical mouthparts. Entomologists have described approximately 7,700 species. They fly only weakly and their feathery wings are unsuitable for conventional flight; instead, thrips exploit an unusual mechanism, clap and fling, to create lift using an unsteady circulation pattern with transient vortices near the wings.