Biological control of cattle fever ticks

Authors: Goolsby, John; Guerrero, Felicito; KASHEFI, JAVID - Non ARS Employee; Smith, Lincoln; RACELIS, ALEX - University Of Texas Rio Grande Valley; CRUZ-FLORES, MARY - De La Salle University; AMALIN, DAVINA - De La Salle University; SINGH, NIRBHAY - Guru Angad Dev Veterinary & Animal Sciences University; AZHAHIANAMBI, P - Non ARS Employee; DEBARRO, PAUL - Csiro European Laboratory; SHEPPPARD, ANDY - Csiro European Laboratory; WYCKUYS, CHRIS - Non ARS Employee; LIU, J - Hebei University; SCHWARTZ, A - Texas Animal Health Commission; HASEL, H - Animal And Plant Health Inspection Service (APHIS); VARNER, K - Animal And Plant Health Inspection Service (APHIS); ELLIS, D - Texas A&M University; Perez De Leon, Adalberto - Beto

Submitted to: Subtropical Agriculture and Environments
Publication Type: Abstract Only
Publication Acceptance Date: 2/3/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary: Cattle fever ticks (CFT) Rhipicephalus (=Boophilus) microplus and Rhipicephalus annulatus are invasive livestock pests that are endemic to Mexico and invasive along the Texas – Mexico border. Acaricide resistance, alternate wildlife hosts, and pathogenic landscape forming weeds present challenges for sustainable eradication of this pest in the U.S. Classical biological control of CFT is being explored as a strategy to control this pest, especially on alternate hosts such as nilgai antelope and white-tailed deer. Genetic fingerprinting was used to compare populations of CFT from Texas to areas in the Old World where they are native to determine where to search for potential biological control agents. CFT from subtropical Zapata, Texas, USA matched most closely with CFT in The Philippines and Cambodia. Similarly, accessions of R. annulatus from Del Rio, TX matched closely with CFT in Bulgaria and Romania. These regions should be prioritized for field exploration for biological control agents.

Technical Abstract: Cattle fever ticks (CFT) Rhipicephalus microplus and Rhipicephalus annulatus are invasive livestock pests that are endemic to Mexico and invasive along the Texas – Mexico border. Acaricide resistance, alternate wildlife hosts, and pathogenic landscape forming weeds present challenges for sustainable eradication of this pest in the U.S. Classical biological control of CFT is being explored as a strategy to control this pest, especially on alternate hosts such as nilgai antelope and white-tailed deer. Molecular genetic tools were used to compare populations of CFT from the native and introduced ranges to provide insights into optimal search areas for potential biological control agents. Accessions representative of invasive populations of R. microplus from subtropical Zapata, Texas, USA and other parts of the invaded range including Brazil and Kenya matched most closely with populations in The Philippines and Cambodia. Similarly, accessions of R. annulatus from invaded range in Del Rio, TX matched closely with accessions from the native range in Bulgaria and Romania. These regions should be prioritized for field exploration for biological control agents. Classical biological control using specialist parasitoids, predators and/or nematodes from the native ranges of cattle fever ticks Rhipicephalus microplus and Rhipicephalus annulatus could complement existing control strategies for this livestock pest in the transboundary region between Mexico and Texas. Methods for field collection of cattle fever tick natural enemies have been developed, including exposure of infested cattle to collect insects that are parasitic on the nymphs and adults, time lapse photography to observe predators of questing larvae, and soil assays to detect entomopathogenic nematodes.