Harnessing environmental microbiological interventions with micro- and macroorganisms for assessing cattle tick...

Area of Science:

• Agricultural Entomology
• Pest Management
• Biological Control

Background:

• Cattle ticks (Rhipicephalus microplus) cause significant economic losses in livestock production globally.
• Sustainable and eco-friendly tick control methods are crucial for integrated pest management strategies.
• Entomopathogens offer a promising alternative to conventional chemical tick treatments.

Purpose of the Study:

• To evaluate the efficacy of combining entomopathogenic fungi (EPF) and entomopathogenic nematodes (EPN) for controlling Rhipicephalus microplus.
• To assess the synergistic effects of Metarhizium spp. and Heterorhabditis bacteriophora against cattle ticks.
• To determine the effectiveness of EPF and EPN in both laboratory and field conditions across different seasons.

Main Methods:

• Laboratory assays using sub-doses of Metarhizium robertsii conidia combined with Heterorhabditis bacteriophora infective juveniles against engorged R. microplus females.
• Field trials assessing a granular formulation of M. robertsii microsclerotia applied with H. bacteriophora infective juveniles in infested pastures.
• Evaluation of tick population reduction during rainy and dry seasons under field conditions.

Main Results:

• Laboratory co-application of EPF and EPN demonstrated synergistic effects, significantly improving tick control.
• Field applications during the rainy season resulted in tick population reductions of 54.09% for M. robertsii, 38.11% for H. bacteriophora, and 46.72% for the combination.
• During the dry season, only the fungal formulation showed significant efficacy, reducing tick populations by 26.27%.

Conclusions:

• The combination of entomopathogenic fungi and nematodes shows potential for synergistic control of Rhipicephalus microplus.
• EPF and EPN can serve as valuable complementary tools for sustainable cattle tick management, reducing reliance on chemical pesticides.
• Seasonal variations influence the efficacy of biological control agents against cattle ticks, highlighting the need for adaptive strategies.