ORIGINAL PAPER Is feeding on mosses by groundhoppers in the genus Tetrix (Insecta: Orthoptera) opportunistic or selective? Kater ˇina Kur ˇavova ´ 1 • S ˇ a ´rka Grucmanova ´ 1 • Zuzana Filipcova ´ 1 • Vı ´te ˇzslav Pla ´s ˇek 1 • Pavel Drozd 1 • Petr Koc ˇa ´rek 1 Received: 6 December 2015 / Accepted: 12 August 2016 Ó Springer Science+Business Media Dordrecht 2016 Abstract Groundhoppers are considered to be detrito- bryophagous, and moss phyllodes represent a main food consumed by all studied species. We studied the food biology of two groundhoppers: the stenotopic habitat spe- cialist Tetrix ceperoi (Bolivar, 1887) and the eurytopic T. tenuicornis (Sahlberg, 1893). These species occurred syn- topically in an abandoned sand pit in the Czech Republic. The dietary preferences of the two species were very similar, with detritus being the dominant component, fol- lowed by mosses and other kinds of organic matter. The eurytopic T. tenuicornis consumed a greater diversity of mosses than the stenotopic T. ceperoi. The most frequently consumed mosses were the dominant species at the locality (Barbula spp., Bryum caespiticium, and Ceratodon pur- pureus), but some species-specific preferences were evi- dent in the consumption of other moss species. To determine whether these groundhoppers mainly consumed mosses to obtain the water in their tissues, we compared the food composition at two sites that differed considerably in water availability. A selective consumption of mosses according to the water availability at the sites was evident. At the dry site, groundhoppers frequently consumed mos- ses that are simultaneously more tolerant to desiccation and nutritionally richer (species in the genera Barbula and Ceratodon) than the other mosses. Our results indicate that although groundhoppers generally consume those mosses that are most available, they do show some preference for mosses according to their nutritional quality and according to their ability to retain water under dry conditions. Keywords Detritophagy Á Bryophagy Á Food selection Á Tetrix ceperoi Á Tetrix tenuicornis Á Tetrigidae Introduction Bryophytes represent a very distinct group of the terrestrial vegetation (Shaw and Renzaglia 2004; Bahuguna et al. 2013). They have unusual life cycles, their hydration is controlled by the environment, and they obtain their nutrients from the substrate, precipitation, and dust (Bahuguna et al. 2013; Hanson and Rice 2014). Bryophytes are able to store large amounts of water, nutrients, and carbon in their biomass (Bahuguna et al. 2013). Moss feeding is uncommon among insects, and true bryophagy has been observed for only a few insect species, i.e. for some bugs and planthoppers (Hemiptera), groundhoppers (Tetrigidae), pill beetles (Coleoptera), caterpillars (Lepi- doptera), fly larvae (Diptera), and baeine wasps (Hy- menoptera) (Verdcourt 1947; Gerson 1969, 1982; Austin 1988; Wheeler 2003; Haines and Renwick 2009). Few insects consume bryophytes because these plants have relatively low caloric values and nutrient contents, a low degree of digestibility, and a large amount of sec- ondary metabolites and anti-feeding substances, such as terpenoids, flavonoids, and other aromatic compounds (Forman 1968, 1969; Rastorfer 1976; Asakawa 1981, 1997; Zinsmeister et al. 1991; Becker 1994; Markham et al. 2007). Because they are poikilohydric, mosses are able to store large amounts of water (they have a high water- holding capacity and are tolerant to desiccation), and dry matter constitutes only a small percentage of their fresh & Petr Koc ˇa ´rek petr.kocarek@osu.cz 1 Department of Biology and Ecology and Institute of Environmental Technologies, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic 123 Arthropod-Plant Interactions DOI 10.1007/s11829-016-9461-9