“…nylanderi (Foitzik & Heinze, 1998, 2000; Foitzik, Sturm, Pusch, d’Ettorre, & Heinze, 2007; Strätz & Heinze, 2004). Furthermore, queenless field colonies might have lost their queen or be fragments of queenright colonies (Cao, 2013; Debout et al., 2007; Smith et al, 2012; Strätz & Heinze, 2004). This population fluidity appears to result from high queen mortality (J. Giehr, unpublished), very high nest densities, the fragility of nest sites, and presumably also a nestmate recognition system strongly based on environmental cues (Foitzik et al., 2007; Heinze, Foitzik, Hippert, & Hölldobler, 1996).…”