ORIGINAL PAPER Can we predict the success of a parasite to colonise an invasive host? Luther van der Mescht 1,2 & Irina S. Khokhlova 2 & Elizabeth M. Warburton 1 & Elizabeth M. Dlugosz 1,3 & Burt P. Kotler 1 & Boris R. Krasnov 1 Received: 31 March 2018 /Accepted: 9 May 2018 # Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract To understand whether a parasite can exploit a novel invasive host species, we measured reproductive performance (number of eggs per female per day, egg size, development rate and size of new imagoes) of fleas from the Negev desert in Israel (two host generalists, Synosternus cleopatrae and Xenopsylla ramesis, and a host specialist, Parapulex chephrenis) when they exploited either a local murid host (Gerbillus andersoni, Meriones crassus and Acomys cahirinus) or two alien hosts (North American heteromyids, Chaetodipus penicillatus and Dipodomys merriami). We asked whether (1) reproductive performance of a flea differs between an alien and a characteristic hosts and (2) this difference is greater in a host specialist than in host generalists. The three fleas performed poorly on alien hosts as compared to local hosts, but the pattern of performance differed both among fleas and within fleas between alien hosts. The response to alien hosts did not depend on the degree of host specificity of a flea. We conclude that successful parasite colonisation of an invasive host is determined by some physiological, immunological and/or behavioural compatibility between a host and a parasite. This compatibility is unique for each host-parasite association, so that the success of a parasite to colonise an invasive host is unpredictable. Keywords Biological invasion . Colonisation . Fleas . Rodents . Muridae . Heteromyidae Introduction Numerous plant and animal species have been either acci- dentally or deliberately introduced to areas beyond their nat- ural ranges as a result of human activities. However, not all introduced organisms have become abundant and wide- spread in novel environments (Mack et al. 2000). Species that succeed in novel geographic areas often achieve en- hanced performance in these areas compared to their native ranges (Grigulis et al. 2001; Jakobs et al. 2004; Stastny et al. 2005; Herrera et al. 2011; but see Thébaud and Simberloff 2001). An invading species can only thrive in a new habitat if it can overcome at least two main obstacles. Firstly, it needs to find the necessary resources to exploit (e.g. food, shelters) in novel conditions (Dobson 1988). Secondly, the introduced species must overcome natural enemies such as predators and parasites in the introduced range (Dobson 1988; Torchin et al. 2001). Obviously, an invader’ s success to evade a local natural enemy depends on the ability of this enemy to exploit this invader. For example, the success of an invasive spider (Achaearanea cf. riparia) was severely limited by local predatory birds (Gruner 2005). If a local enemy is not able to exploit an invader for any reason, the latter will likely perform well in novel conditions given that it has enough resources. For example, the European rabbit (Oryctolagus cuniculus) rapidly colonised Australia mainly due to the lack of predators (Jernelöv 2017) and parasites (Dunsmore 1981) for which rabbits represented a suitable prey and host, respectively. The ability of a local parasite to use an invader may depend on a variety of factors. These dynamics can be explained in the framework of the host-encounter and host-compatibility * Luther van der Mescht vanderme@post.bgu.ac.il 1 Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, 84990 Midreshet Ben-Gurion, Israel 2 Wyler Department of Dryland Agriculture, French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84990 Midreshet Ben-Gurion, Israel 3 Present address: Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996, USA Parasitology Research https://doi.org/10.1007/s00436-018-5921-8