Water Is Needed to Exist: Habitat Preferences of Tiger Beetles (Coleoptera: Cicindelidae) in a Desert Country

SIMPLE SUMMARY: Many species of tiger beetles are habitat specialists, which make them useful as bioindicators of the status and changes in the quality of the environment. Their diversity and community structure in particular habitats can point to the stability of habitat. We studied six different macro and microhabitat factors that influence the habitat preferences of four Cicindelidae species occurring in different Tunisian desert areas. This is the one of only a few such studies in Africa. The results clearly show high habitat specialization of most studied taxa, as well as importance of water reservoirs in species distribution in the Sahara Desert. ABSTRACT: Tiger beetles are a group of predatory insects occurring mainly in diverse sandy areas, with particular species often characterised by narrow habitat preferences, which makes them both very important bioindicators for determining patterns of biodiversity and a flagship group for nature conservation. However, the precise roles of particular habitat parameters in the distribution of these beetles in desert areas are almost unknown. Habitat preferences for four tiger beetles species were analysed in Tunisia. Fifty samples from a major part of the country were collected, for which climate data, macrohabitat types. and soil parameters (soil humidity, salinity, pH, and structure) were studied. Here we show that most studied Cicindelidae were characterised by unique habitat preferences and did not co-occur with other ones, including two taxa found as habitat specialists, occurring in only one type of macrohabitat. Two other species were noted as more eurythopic and occupied 2–3 macrohabitat types, with Lophyra flexuosa as the most ubiquitous species not related to the measured parameters. The presence of a source of water (understood as a part of the habitat type, such as river banks and oases, or high soil humidity) was found as the most important factor in the distribution of the studied tiger beetle species. The present study is the first one focused on habitat preferences and habitat specialization of Cicindelidae fauna of Maghreb, and one of only a few in Africa.