Kriska, György, DSc
Animal Ecology Research Group
+36 1 279 3100
freshwater invertebrates, visual ecology, polarisation vision, ecological traps
 Polarized light pollution and polarization ecological traps
Ecological photopollution (EPP) has been defined as the degradation of the photic habitat by artificial light. We introduced a new term, the polarized light pollution (PLP), meaning all adverse effects on polarotactic aquatic insects attracted by horizontally polarized light reflected from artificial surfaces. PLP is a new kind of EPP, it is global and novel in an evolutionary sense. In numerous choice experiments with polarotactic insects and using imaging polarimetry we gave experimental evidence of PLP, such as (1) trapping of aquatic insects by dark oil surfaces; (2) dehydration of polarotactic insects attracted to black plastic sheets used in agriculture; (3) egg-laying of polarotactic mayflies onto dry asphalt roads; (4) attraction of aquatic insects to black, red or dark-coloured car paintwork; (5) deception of polarotactic dragonflies by shiny black gravestones; (6) attraction of mass-swarming polarotactic caddis flies to glass surfaces. All such highly and horizontally polarizing artificial surfaces can act as polarized ecological traps for polarotactic insects, because these surfaces are inappropriate for the development of eggs laid by the deceived insects. The mortality associated with PLP may threaten populations of endangered aquatic insect species. We pointed onto some possible benefits and/or disadvantages of predators (spiders, birds, bats) feeding on the polarotactic insects attracted to different sources of PLP. We also suggested several remedies of PLP, which is a byproduct of the human architectural, building, industrial and agricultural technology, and it may allow to function feeding webs composed of polarotactic insects and their predators. We emphasized that conservation planners should pay much more attention to aquatic insects because of their positive polarotaxis and their demonstrated vulnerability due to PLP.
 Polarization tabanid traps – TabaNOid technology
To know how tabanid flies locate their host animals, terrestrial rendezvous sites and egg-laying places would be very useful for control measures against them, because the haematophagous tabanid females are vectors of some severe animal/human diseases/parasites. In choice experiments we discovered that both males and females of several tabanid species have positive polarotaxis, i.e. they are attracted to horizontally polarized light stimulating their ventral eye region. The novelty of this is that polarotaxis has been described earlier only in connection with the water detection of aquatic insects ovipositing directly into water. A further particularity of our discovery is that in the order Diptera and among blood-sucking insects the studied tabanids are the first known species possessing ventral polarization vision and definite polarization-sensitive behaviour with known functions. The polarotaxis in tabanids makes it possible to develop new optically luring traps being more efficient than the existing ones. The development of our patented protective system, called TabaNOid, against tabanids for eco-farms, graziers and race-horse breeders is in progress.