Trap shape affects efficacy of sticky traps for New World screwworm, Cochliomyia hominivorax (Diptera: Calliphoridae).

New World screwworm, Cochliomyia hominivorax (Coquerel), is an obligate parasite of warm-blooded animals and a serious threat to livestock, wild animals, and humans. The sterile insect technique (SIT) was used to eradicate screwworm from North and Central America during the mid-1900s to the early-2000s. Traps are an important tool for screwworm control programs, where they are used for surveillance, evaluation of production strains, and to estimate the ratio of wild to sterile flies following aerial and ground releases. Here, we tested two trap designs for capturing New World screwworm. The vertical sticky trap, the trap currently used, is a triangle-shaped trap with 1,710 cm2 surface area coated with insect adhesive. The cylinder sticky trap is a cylinder-shaped trap with 1,700 cm2 surface area coated with the same insect adhesive. Both traps were baited with swormlure-4 as an attractant. We used a release-recapture study with a randomized block design to test the efficacy of the two trap designs. The cylinder sticky trap captured significantly more C. hominivorax than the vertical sticky trap, likely due to an increase in the ability of the flies to land on the surface of the cylinder-shaped trap.