<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>
<p class="jbls"><span lang="EN-GB">Several families of mammals have stripes and many hypotheses have been proposed to explain the evolution of the striped coat patterns. However, there is very limited experimental evidence to support which hypotheses are the most likely to explain the evolution of the striped patterns. Therefore, what adaptive function the stripes serve in all these species is still largely unknown. In this study I investigated the characteristics of stripes such as stripe width for both white and black stripes on 36 striped African mammals’ coats collected in four museums and three countries. My study further revealed that the appearance of stripes on mammalian coats is most likely not involved in sexual selection. There were close similarities in stripes number or stripes width between sexes for <em>Equus grevyi</em> and <em>Tragelaphus</em> <em>imberbis</em>. In order to evaluate the effects of stripes on tabanids attractiveness, two experiments designed to test tabanids attraction were performed. Data on tabanids daily activity revealed that the flies were more active on partly cloudy and sunny weather. Especially, <em>Haematopota pluvialis</em> is known to have a high flight intensity in cloudy weather before an anticipated rain. Using sticky panels and models, tabanids were more attracted to sunny sides in the both experiments. Moreover, the findings revealed that the stripes in all striped patterns were extremely important in stimulating tabanid flies’ repellency. My results suggest that the appearance of stripes on different mammalian coats could be an evolutionary force reducing the attraction of tabanids to many striped animals, consequently, reducing disease transmission risk.</span></p>
Information about the important factors in tabanid flies visual orientation to hosts has been largely derived from experimental modifications of visual traps and decoys. In the present study performed in wood pasture (Hästhult), southern Sweden, three-dimensional striped models resembling the shape of Zebra, Bongo, Kudu and four control models of different homogenous colors (black, white, reddish-brown and brown) were baited with acetone and aged cow urine in order to test the behavioral preferences in terms of visual and olfactory stimuli in host-seeking tabanids. Attraction of tabanid flies to these models (3D) was high, possibly due to the greater visibility from several directions and also from a greater distance. Vision is important in activating, orienting tabanid flies to the host, as well as for their decision whether and where to land. This research revealed that the visual cues such as stripes on striped models became increasingly important in directing tabanids landing and searching behavior at close range. Likewise, the tabanids approach to attractants sources was overridden by visual cues (stripes) at greater extent compared with the more attractiveness to homogenous colors on control models. Moreover, the visual stimuli (stripes) played also a supplementary role, modifying the selection of landing area on striped model (land on homogenous color part in Bongo and Kudu) once alighting responses were initiated by odor. Tabanid species, especially Haematopota pluvialis and Tabanus bromius exhibited a preference for landing mostly on reddish-brown control model when given the choice of other colors. However, the complex interaction of attractants and visual cues (stripes, color, shape) in the later stages of resource location, remains relatively little studied in all species of tabanids.
The distribution and species diversity of tabanids and stable flies, Stomoxys calcitrans Linnaeus, 1758, in the research area, Hästhult (wood pasture) in Sweden, as well as the behavioral responses of biting flies to visual and olfactory cues were highlighted by this study. Beyond the control of tabanids and stable flies through the Nzi and Horse Pal traps that act as a surrogate host, this study sought to demonstrate the attractiveness of biting flies to these traps by comparing the results of the two periods in which the traps were unbaited and baited. The odor attractants, such as urine (a mixture of more than phenol) and acetone used to increase trap yields, made the difference to the Horse Pal and Nzi traps for S. calcitrans (L) because the number of flies caught was significantly higher. Through this study, Nzi trap with bait and Horse Pal trap with and without bait were tested for the first time as regards the tabanids and S. calcitrans (L) in Scandinavia. Surprisingly, the number of tabanids caught in the Nzi trap was equal in both situations with or without bait. The result underlined the idea that the Nzi trap manages to catch a large number of tabanids even in the absence of attractants. It turns out that the Horse Pal trap was just as effective with and without bait in capturing tabanids. Furthermore, the number of tabanids caught in both traps depended on the type of weather, and the number of stable flies depended on the weather and also the type of trap. The results of this study showed that both the visual and olfactory aspects of the Nzi and Horse Pal traps are always essential, being used successfully in the control of biting flies and optimized for various research purposes.
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