Developing a qPCR Method for Evaluating Parasitoid Wasps as a Potential Means of Control of the Southern Cattle Fever Tick Rhipicephalus (Boophilus) Microplus in South Texas

Author

• Abbey Abalos, The University of Texas Rio Grande Valley

Date of Award

5-1-2026

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

First Advisor

Sarah Mays Maestas

Second Advisor

Christopher Vitek

Third Advisor

Frank Dirrigl

Abstract

Ixodiphagus spp. wasps are natural enemies of ticks that have been reported to cause mortality in multiple tick species. Parasitoid wasps may represent a potential biocontrol alternative to traditional chemical tick control methods, which are challenged by non-target toxicity and the development of pesticide resistance in species of concern such as Rhipicephalus microplus, a pest of livestock that causes billions of dollars in loss to the livestock industry worldwide. Rhipicephalus sanguineus s.l. is a congeneric species of R. microplus, and parasitism of R. sanguineus by Ixodiphagus sp. in areas of co-occurrence has been observed. It is unknown if R. microplus also is parasitized by this parasitoid species.

The goal of this study was to develop a qPCR assay for detection of the target parasitoid in DNA extracted from R. sanguineus s.l. collected from Vietnam, a country within the native range of both R. sanguineus and R. microplus. The qPCR assay was developed as a species-specific qPCR that results in amplification of parasitoid DNA while minimizing non-target arthropod DNA amplification. This protocol was used to screen for parasitoid infestations in R. sanguineus s.l. and will be used to screen for parasitoids in R. microplus in the future. Seventy R. sanguineus s.l blood-fed nymphs were screened for detection of parasitoids. Amplification of parasitoid DNA occurred in five out of the 70 ticks screened.

Additionally, ticks from south Texas are being screened for infestation by Ixodiphagus hookeri, which is distributed worldwide, using DNA extractions from Amblyomma mixtum, a common south Texas species, and R. sanguineus s.l.

Comments

Copyright 2026 Abbey Abalos. All Rights Reserved. https://proquest.com/docview/3371164779

Recommended Citation

Abalos, A. (2026). Developing a qPCR Method for Evaluating Parasitoid Wasps as a Potential Means of Control of the Southern Cattle Fever Tick Rhipicephalus (Boophilus) Microplus in South Texas [Master's thesis, The University of Texas Rio Grande Valley]. ScholarWorks @ UTRGV. https://scholarworks.utrgv.edu/etd/1925