Fleas from nilgai and native wildlife in south Texas

Authors: MAESTAS, SARAH - University Of Texas Rio Grande Valley; Maestas, Lauren

Submitted to: Subtropical Agriculture and Environments
Publication Type: Proceedings
Publication Acceptance Date: 2/8/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Fleas are parasites commonly found on wildlife and domestic animals. Species such as mice, pigs, birds and even humans are commonly affected by fleas and flea-borne pathogens; however, large species of herbivores such as deer are rarely parasitized by fleas. In South Texas, white-tailed deer, feral hogs and javelina have been found to be parasitized by a specialist feeding flea species, dubbed the javelina flea. Nilgai antelope are large, free-ranging exotic herbivores that have become established in south Texas. Nilgai can act as hosts for pests of livestock that may be able to transmit agents of human and animal disease. Interactions of nilgai with native ectoparasite species in south Texas remain relatively understudied. Fleas were opportunistically collected from wildlife hosts during depredation hunts or nilgai collaring activities in Hidalgo, Starr, and Cameron Counties in south Texas. Two flea species have been identified: Pulex porcinus, the javelina flea, was collected from nilgai antelope, as well as from black-tailed jackrabbits, cottontail rabbits, coyotes, bobcat, feral swine, and javelina, and Euhoplopsyllus glacialis affinis Baker from cottontail rabbits. This is the first known report of this species from nilgai antelope, and to our knowledge the first report of fleas of any species collected from nilgai antelope. While the pathogen transmission potential of this species for common flea-borne pathogens is not known, South Texas is a hotspot for human cases of flea-borne Rickettsia. Personal observation indicates that P. porcinus will bite people. These findings indicate the importance of investigating understudied and cryptic species and a need to further evaluate the relationship of this flea with Rickettsia in rural south Texas.

Technical Abstract: Fleas are common ectoparasites of wildlife and domestic animals. Species such as rodents, swine, fowl and even primates are commonly affected by fleas and flea-borne pathogens; however, large ungulates such as deer are rarely parasitized by fleas. In South Texas, white-tailed deer (Odocoileus virginianus), feral hogs (Sus scrofa) and javelina (Pecari tajacu) have been found to be parasitized by Pulex porcinus Jordan and Rothschild, the javelina flea. Nilgai antelope (Boselaphus tragocamelus Pallas) are large, free-ranging exotic ungulates that have become established in south Texas. Nilgai can act as hosts for ectoparasite species that are pests of livestock and vectors of human and animal disease, however, their interactions with native ectoparasite species in south Texas remain relatively understudied. Fleas were opportunistically collected from wildlife hosts during depredation hunts or nilgai collaring activities in Hidalgo, Starr, and Cameron Counties in south Texas. Two flea species have been identified: Pulex porcinus, the javelina flea, was collected from nilgai antelope, as well as from black-tailed jackrabbits, cottontail rabbits, coyotes, bobcat, feral swine, and javelina, and Euhoplopsyllus glacialis affinis Baker from cottontail rabbits (Sylvilagus spp.). This is the first known report of this species from nilgai antelope, and to our knowledge the first report of fleas of any species collected from nilgai antelope. While the vector competence of this species for common flea-borne pathogens is not known, South Texas is a hotspot for human cases of flea-borne Rickettsia. Personal observation indicates that P. porcinus will bite people. These findings indicate the importance of investigating understudied and cryptic species and a need to further evaluate the relationship of this flea with Rickettsia in rural south Texas.