Abstract: Biological Control of Cattle Fever Ticks

Authors: Goolsby, John

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/28/2022
Publication Date: N/A
Citation: N/A

Interpretive Summary: Cattle fever ticks (CFT) are invasive livestock pests that are endemic to Mexico and invasive along the Texas – Mexico border. Pesticide resistance, alternate wildlife hosts, and pasture weeds that help ticks survive all present challenges for sustainable eradication of this pest in the U.S. CFT are the vector for bovine babesiosis, a lethal disease causing high mortality particularly in cattle. Efforts to eradicate CFT from the United States have been successful; however, in recent years, there has been an increase in CFT infestations outside of the Permanent Quarantine Zone in Texas. New methods for treatment of cattle fever tick-infested whitetailed-deer and nilgai are needed. Classical biological control of CFT is a component of IPM that could be integrated into the CFT eradication strategy in the transboundary region between Texas and Mexico. The research methods to discover specialist biological control agents (parasitic tick wasps) in the native range of cattle fever ticks (Eurasia) are discussed in this paper.

Technical Abstract: As tick species are studied in their native range, parasitism by Ixodiphagous parasitoids (Encyrtidae: Hymenoptera) appears to play an important role in their ecology. We hypothesize that the specialist Ixodiphagus parasitoids occur in the native range of Cattle fever ticks (CFT), Rhipicephalus (=Boophilus) microplus Canestrini and Rhipicephalus (=Boophilus) annulatus (Say) (Ixodida: Ixodidae). Methods to collect Ixodiphagous wasps using R. microplus or R. annulatus infested cattle and have been tested in the native range including Vietnam, Bulgaria and Greece. These methods may be the best way to collect Ixodiphagous, but they are very intensive requiring a high level of cooperation between researchers and local farmers to collect engorged nymphs from infested host animals. We have recently begun exposing larvae of R. microplus in Vietnam to determine if this off-host life stage is parasitized. We also hypothesize that Ixodiphagus parasitoids reared from three host ticks that occur in sympatry within the native range of cattle fever ticks may have a host range that includes R. microplus or R. annulatus. In addition, general collections of cattle fever tick larvae/nymphs and sympatric 3 host tick nymphs can be used for molecular detection of Hymenopteran (Ixodiphagous) DNA, which could improve timing and location of biological control surveys for parasitoids. Discovery and establishment of a specialist parasitoid for cattle fever ticks could have significant impacts and enhance the efficiency and sustainability of the Cattle Fever Tick Eradication Program in the transboundary region between Texas and Mexico and worldwide where CFT are invasive.