Stripes disrupt odour attractiveness to biting horseflies: Battle between ammonia, CO2, and colour pattern for dominance in the sensory systems of host-seeking tabanids

PHYSIOLOGY & BEHAVIOR

卷:119

Article

Blaho, Miklos¹  Egri, Adam¹  Szaz, Denes¹  Kriska, Gyoergy^2,3  Akesson, Susanne⁴  Horvath, Gabor¹ 

[1] Eotvos Lorand Univ, Inst Phys, Dept Biol Phys, Environm Opt Lab, H-1117 Budapest, Hungary

[2] Eotvos Lorand Univ, Inst Biol, Grp Educ Biol Teaching, H-1117 Budapest, Hungary

[3] Hungarian Acad Sci, Ctr Ecol Res, Danube Res Inst, H-2163 Vacratot, Hungary

[4] Lund Univ, Ctr Anim Movement Res, Dept Biol, SE-22362 Lund, Sweden

关键词: Zebra;    Tabanid fly;    Horsefly;    Striped pattern;    Parasite protection;    Ammonia;    Carbon dioxide;    Olfactory cues;    Polarisation vision;    Polarotaxis;    Visual ecology;   

DOI  :  10.1016/j.physbeh.2013.06.013

来源: Elsevier

【 摘 要 】

As with mosquitoes, female tabanid flies search for mammalian hosts by visual and olfactory cues, because they require a blood meal before being able to produce and lay eggs. Polarotactic tabanid flies find striped or spotted patterns with intensity and/or polarisation modulation visually less attractive than homogeneous white, brown or black targets. Thus, this reduced optical attractiveness to tabanids can be one of the functions of striped or spotty coat patterns in ungulates. Ungulates emit CO2 via their breath, while ammonia originates from their decaying urine. As host-seeking female tabanids are strongly attracted to CO2 and ammonia, the question arises whether the poor visual attractiveness of stripes and spots to tabanids is or is not overcome by olfactory attractiveness. To answer this question we performed two field experiments in which the attractiveness to tabanid flies of homogeneous white, black and black-and-white striped three-dimensional targets (spheres and cylinders) and horse models provided with CO2 and ammonia was studied. Since tabanids are positively polarotactic, i.e. attracted to strongly and linearly polarised light, we measured the reflection-polarisation patterns of the test surfaces and demonstrated that these patterns were practically the same as those of real horses and zebras. We show here that striped targets are significantly less attractive to host-seeking female tabanids than homogeneous white or black targets, even when they emit tabanid-luring CO2 and ammonia. Although CO2 and ammonia increased the number of attracted tabanids, these chemicals did not overcome the weak visual attractiveness of stripes to host-seeking female tabanids. This result demonstrates the visual protection of striped coat patterns against attacks from blood-sucking dipterans, such as horseflies, known to transmit lethal diseases to ungulates. (C) 2013 Elsevier Inc. All rights reserved.

【 授权许可】

Free