A study on bloodsucking Tabanidae and Stomoxys calcitrans (Diptera) attacking horses and cows in Northern Scania, Sweden

Abstract

<p class="jbls"><span lang="EN-US">In Sweden, during summer, grazing horses and cows are frequently exposed to bloodsucking flies. This study has been performed in the geographical areas of Gundrastorp (pasture) and Kämlehöjalt (wood pasture), in northern Scania, Sweden where the occurrences of biting flies may represent a scourge for domesticated animals. The distribution of biting flies, Tabanidae and <em>Stomoxys calcitrans</em> (L) (known as stable flies) was studied by insect trapping using two Nzi traps, one for each habitat. No attractants have been used in order to improve trap capture rate. This research pointed out that tabanid and stable flies did not show any preference between the two landscape types or between hosts where they get their blood meal. Capture rates increased on days with high temperature. There were also differences in number between all types of weather for both tabanid and stable flies. In terms of species activity in all types of weather, 13 species of Tabanidae displayed some differences between them in each habitat. In the genus Tabanus, <em>Tabanus bromius</em> and <em>Tabanus maculicornis</em> showed similar patterns with regards to daily activity in different types of weather, being followed by <em>Haematopota pluvialis </em>and<em> Hybomitra bimaculata</em>. Moreover, with regards to the number of male and female tabanids collected in Nzi traps, a higher difference for each area was found. As a parallel survey, the landing behavior of each genus of collected tabanids on blue and black colors before going into Nzi traps showed the same variation during the experiments. Nzi traps set near the horses and cows have shown high efficiency in capturing biting flies, allowing animals to graze somewhat undisturbed.</span></p>

Behavioral Responses of Tabanidae and Stomoxys calcitrans to Unbaited and Baited Nzi and Horse Pal Traps in Southern Sweden

“…All the flies enter a collecting bottle positioned above directly through a funnel and then fall into a collecting bag where they eventually die because they cannot return. The effectiveness of this trap has been demonstrated in several places around the world, especially by catching at the same time several different types of biting flies such as tabanids, stable flies and tsetse (Mihok, 2002;Van Hennekeler et al, 2008;Vaduva, 2016).…”

“…Without the blood meal, the eggs of some female biting flies cannot be matured. Likewise, tabanids and stable flies, S. calcitrans (L) freely movement from one animal to another trying to obtain a blood meal, resulting in a mechanical transmission of disease such as tularemia, anthrax and besnoitiosis a cattle disease (the causative agent, Besnoitia besnoiti is a cyst-forming coccidian parasite) widespread throughout Europe, Africa and Asia (Allan et al, 1987;Lié nard et al, 2013;Vaduva, 2016). S. calcitrans (L) is a diurnal species, being less tied to livestock might travel widely in its searching of breeding sites and hosts (Wood, 1985).…”

“…It is an important vector of Trypanosoma evansi and Habronema microstoma, a horses' nematode (Wood, 1985;Mullens, 2002;Vaduva, 2016). A Stomoxys flies' outbreak in April and May 1997, led to the death of a large number of ungulates including Bongo over a large area of the trinational region of Cameroon -Congo -Central African Republic (Kingdon, 1982).…”

“…Tabanids are considered to be the mechanical vectors of thirsty five pathogenic agents including Anaplasma marginale, Trypanosoma vivax, Loa loa etc. (Foil and Hogsette, 1994;Vaduva, 2016). The most important diseases transmitted by deer flies to humans through repeated baits, are loiasis and tularemia (Mullens, 2002).…”

“…However, Nzi and Horse Pal traps have proven to be practical and effective in capturing a large number of tabanids, stable flies and tsetse. Studies with Nzi trap have been made in North America, Australia, Africa and also in northern Skå ne, Sweden (Vaduva, 2016). Horse Pal trap is considering to be an efficient trap by catching a plenty of horse flies in North America, where tabanids are particularly abundant, especially in forested regions.…”