Caenocholax fenyesi is a species of twisted-winged parasitic insects in the order Strepsiptera and family Myrmecolacidae.

[2] C. fenyesi displays heterotrophic heteronomy, where males and females occupy different hosts.

[6] These three subspecies belong to the species Caenocholax fenyesi:[6] Phylogenetic relationships are inferred based on the morphology of adults and specific host associations.

[3] Overall distribution in the United States includes Florida, New Orleans, southern and central Louisiana, Mississippi, Georgia, Arizona, Alabama, and Texas.

[3] In the Neotropics, they are found in Cordoba, Mexico; Tabasco, Mexico; Peten, Guatemala; Metagalpa, Nicaragua; Costa Rica; Panama; Ecuador; Chile; Missiones, Argentina; Andros Island, Bahamas; and Cuba.

[3] Individuals live in small numbers in close proximity due to the adult male's short lifespan.

Poorly developed flight and short lifespans also constrain dispersal by males.

[4] Overall, dispersal of male first instar larvae is extremely limited because adult and nymph stages of the ant host live within the same habitat.

[5] Motile first instar larvae are released through the brood canal opening in the female's cephalothorax.

Copulation may occur for up to a minute and multiple times before the male begins searching for another female to mate with[6].

[6] At this stage, individuals have a scleratized cuticle and are brown and 70-80 um long, not including the caudal filaments.

[5][2] Ventral regions of the head, thorax, and abdomen are serrated, and dorsal and lateral surfaces are mainly smooth.

[5][2] Legs are slender and spined, and tarsi have single joints, no claws, and ventral modifications to resemble adhesive pads.

[2] Individuals at this stage are 200-350 um in size and light brown, with a rounded head and membraneous cuticle.

[2] This stage is similar to the secondary larva, but individuals are much larger at 600-700 um in size, and the head is less rounded and cap-like with a broadly pointed anterior end.

[2] Females are wingless, eyeless, and possess no antennae, mouthparts, legs, or external genitalia.

[10] The female's head is vestigial and is fused to the reduced, indistinct segments of the thorax.

[5] C. fenyesi has been suggested as a potential agent for the biological control of the red imported fire ant, S. invicta in the United States and Australia[10].

[3] S. invicta was introduced into the United States from South America in the early 1900s and have since expanded their range to cover more than 129.5 million hectares.