The ‘Avrona Nature Reserve in Israel is a unique hyper-arid area that was contaminated twice by crude oil, first in 1975 and again in 2014. A recent four-year arthropods field survey in the reserve found only small numbers of antlions and beetles in the contaminated areas (including the areas contaminated in 1975), raising the question of whether the arthropods avoid the contaminated areas on purpose, or whether they use it indiscriminately, but don’t survive on it.
We performed habitat selection experiments in the lab in which Mesostena angustata beetles and Myrmeleon hyalinus antlion larvae were given choice trials between different combinations of clean and contaminated soils from the 1975 and 2014 oil spills from the ‘Avrona Reserve. Surprisingly, both beetles and antlions selected the 1975 contaminated soil over other soil types. Antlions reduced their movements and did not dig any pit-traps in contaminated soil from 2014, but they did manage to dig in the contaminated soil from 1975 and the clean soil.
These results raise the question whether the oil-contaminated soil has certain advantages for arthropods or whether their attraction to contaminated soil creates an ecological trap for these species.