The influence of distance on movement of tabanids (Diptera: Tabanidae) between horses.

The study discusses two experiments conducted to establish the influence of distance on the movement of tabanids (types of horseflies) between two horses and how it aids in the reduction of mechanical disease transmission.

Study Overview

• The series of investigations were aimed at evaluating whether spatial barriers could be useful in reducing the mechanical transmission of disease agents by tabanids.
• The studies took place in the Pantanal region of Brazil, an area associated with a high population of these insects.

First Study

• In the initial study, tabanids at stations separated by four different distances (5, 10, 25 and 50 meters) were marked for identification.
• These marked tabanids were allowed to feed on a horse until they were full or naturally interrupted. If these flies then transferred to another horse, they were captured and noted.
• A total of 2847 tabanids from nine different species were marked and observed.
• The percentage of tabanids that moved between horses was found to be 10.5% at 5 meters, 6.8% at 10 meters, and 4.6% at a distance of 25 meters.

Second Study

• In the second experiment, once the flies were marked, their feeding was interrupted, and they were released about 50cm from the host horse.
• This marked group included 1274 tabanids from five different species.
• The percentage of these flies that moved between horses was recorded as 9.7% at 5 meters, 9.7% at 10 meters, and 4.6% at 25 meters.

Key Findings and Implications

• Through both the experiments, it was observed that no tabanids transferred between animals separated by a distance of 50 meters.
• Based on the results, the research provided strong evidence to the claim that segregating animals more than 50 meters apart can effectively prevent the mechanical transmission of diseases by tabanids.
• This insight could substantially benefit animal husbandry practices and control of diseases that are transmitted through these vectors.