find d odd one out

1. cactoblastic cactorum
2. helianthus annus
3. phytophthora
4. cochliomyia

The correct option is 4.
Cochliomyia is a genus in the family Calliphoridae, known as blowflies, in the order Diptera. Cochliomyia are commonly referred to as the New World screwworm fly. There are four species in this genus: Cochliomyia macellaria, Cochliomyia hominivorax, Cochliomyia aldrichi, and Cochliomyia minima. The two main species are Cochliomyia hominivorax and Cochliomyia macellaria.