Spottier Targets Are Less Attractive to Tabanid Flies: On the Tabanid-Repellency of Spotty Fur Patterns
نویسندگان
چکیده
During blood-sucking, female members of the family Tabanidae transmit pathogens of serious diseases and annoy their host animals so strongly that they cannot graze, thus the health of the hosts is drastically reduced. Consequently, a tabanid-resistant coat with appropriate brightness, colour and pattern is advantageous for the host. Spotty coats are widespread among mammals, especially in cattle (Bos primigenius). In field experiments we studied the influence of the size and number of spots on the attractiveness of test surfaces to tabanids that are attracted to linearly polarized light. We measured the reflection-polarization characteristics of living cattle, spotty cattle coats and the used test surfaces. We show here that the smaller and the more numerous the spots, the less attractive the target (host) is to tabanids. We demonstrate that the attractiveness of spotty patterns to tabanids is also reduced if the target exhibits spottiness only in the angle of polarization pattern, while being homogeneous grey with a constant high degree of polarization. Tabanid flies respond strongly to linearly polarized light, and we show that bright and dark parts of cattle coats reflect light with different degrees and angles of polarization that in combination with dark spots on a bright coat surface disrupt the attractiveness to tabanids. This could be one of the possible evolutionary benefits that explains why spotty coat patterns are so widespread in mammals, especially in ungulates, many species of which are tabanid hosts.
منابع مشابه
An unexpected advantage of whiteness in horses: the most horsefly-proof horse has a depolarizing white coat.
White horses frequently suffer from malign skin cancer and visual deficiencies owing to their high sensitivity to the ultraviolet solar radiation. Furthermore, in the wild, white horses suffer a larger predation risk than dark individuals because they can more easily be detected. In spite of their greater vulnerability, white horses have been highly appreciated for centuries owing to their natu...
متن کاملA horizontally polarizing liquid trap enhances the tabanid-capturing efficiency of the classic canopy trap.
Host-seeking female tabanid flies, that need mammalian blood for the development of their eggs, can be captured by the classic canopy trap with an elevated shiny black sphere as a luring visual target. The design of more efficient tabanid traps is important for stock-breeders to control tabanids, since these blood-sucking insects can cause severe problems for livestock, especially for horse- an...
متن کاملExperimental Study of Tabanid Polarotaxis, Host-Tabanid Interaction and Polarization Tabanid Traps Summary of Ph.D. Thesis
متن کامل
Performance of painted plywood and cloth Nzi traps relative to Manitoba and greenhead traps for tabanids and stable flies.
Experiments were conducted to adapt the cloth Nzi trap to a format suitable for fixed applications in biting fly sampling or control. Catches of tabanids [Tabanus L., Chrysops (Meigen), and Hybomitra Enderlein], and stable flies [Stomoxys calcitrans (L.)] in painted plywood traps were compared with those in standard phthalogen blue cloth traps, and in similarly painted cloth traps. The Manitoba...
متن کاملPhorcotabanus cinereus (Wiedemann, 1821) (Diptera, Tabanidae), an ornithophilic species of Tabanid in Central Amazon, Brazil.
In Central Amazon, Brazil, the tabanid Phorcotabanus cinereus (Wiedemann) was recorded attacking the native duck Cairina moschata (Linnaeus) (Anseriformes, Anatidae). The flight and behavior of the tabanid during the attacks and the host's defenses were videotaped and analyzed in slow motion. The tabanid was recorded flying rapidly around the heads of the ducks before landing. Landing always to...
متن کامل