[Attack of black flies (Diptera, Simuliidae) on horses in Basel (Switzerland)].

The research presents an observation made in April 1996 about an attack on horses by black flies in Basel, Switzerland. The specific flies involved were female Simulium erythrocephalum and Simulium ornatum, with some partaking in a blood meal from horses – a first recorded instance for S. ornatum in Switzerland.

Overview of the Study

• The study primarily documents an incidence of black flies attacking horses in Basel, Switzerland during April 1996.
• The researchers identified the flies involved as females from the Simulium species – specifically, S. erythrocephalum and S. ornatum.

Black Flies in Switzerland

• Black flies are small insects belonging to the Simuliidae family, under the larger Diptera order, which also includes flies, mosquitoes and gnats among other insects.
• In this specific instance in Basel, the attacking females belonged to the S. erythrocephalum and S. ornatum species.

Initial Observations and Discoveries

• During the observed attack, the researchers noted that a portion of the black flies had taken a blood meal from the horses, which indicates that they feed on blood, a behaviour known as hematophagy.
• This feeding behaviour, especially involving horses as the host, is considered significant enough to be the focus of the research.

Significance and Implications

• The event recorded in this research is significant because it marked the first time in Switzerland that S. ornatum was observed taking blood meals from horses.
• This implies new insight into the feeding behaviour of S. ornatum in Switzerland and potentially impacts our understanding of the species’ ecological relationship with horses and potential vector-borne disease transmission.