02851nas a2200241 4500008004100000245012100041210006900162260001600231300001600247490000600263520210600269653001402375653001702389653001902406653000902425653002402434653001302458100002702471700002002498700002302518700002502541856004302566 2017 eng d00aHost sympatry and body size influence parasite straggling rate in a highly connected multihost, multiparasite system0 aHost sympatry and body size influence parasite straggling rate i cJan-06-2017 a3724 - 37310 v73 a

Parasite lineages commonly diverge when host lineages diverge. However, when large clades of hosts and parasites are analyzed, some cases suggest host switching as an- other major diversification mechanism. The first step in host switching is the appear- ance of a parasite on an atypical host, or “straggling.” We analyze the conditions associated with straggling events. We use five species of colonially nesting seabirds from the Galapagos Archipelago and two genera of highly specific ectoparasitic lice to examine host switching. We use both genetic and morphological identification of lice, together with measurements of spatial distribution of hosts in mixed breeding colonies, to test: (1) effects of local host community composition on straggling parasite identity; (2) effects of relative host density within a mixed colony on straggling frequency and parasite species identity; and (3) how straggling rates are influenced by the specifics of louse attachment. Finally, we determine whether there is evidence of breeding in cases where straggling adult lice were found, which may indicate a shift from straggling to the initial stages of host switching. We analyzed more than 5,000 parasite individuals and found that only ~1% of lice could be considered stragglers, with ~5% of 436 host individuals having straggling parasites. We found that the presence of the typical host and recipient host in the same locality influenced straggling. Additionally, parasites most likely to be found on alternate hosts are those that are smaller than the typical parasite of that host, implying that the ability of lice to attach to the host might limit host switching. Given that lice generally follow Harrison’s rule, with larger parasites on larger hosts, parasites infecting the larger host species are less likely to successfully colonize smaller host species. Moreover, our study supports the general perception that successful colonization of a novel host is extremely rare, as we found only one nymph of a straggling species, which may indicate successful reproduction.

10aGalapagos10ahost breadth10ahost switching10alice10aparasite speciation10aseabirds1 aRivera-Parra, Jose, L.1 aLevin, Iris, I.1 aJohnson, Kevin, P.1 aParker, Patricia, G. uhttp://doi.wiley.com/10.1002/ece3.297102407nas a2200229 4500008004100000245017700041210006900218260001600287300001600303490000600319520161500325653001701940653002301957653002001980653001402000653001402014100002702028700002002055700002302075700002502098856005402123 2015 eng d00aLineage sorting in multihost parasites: Eidmanniella albescens and Fregatiella aurifasciata on seabirds from the Galapagos Islands0 aLineage sorting in multihost parasites iEidmanniella albescensi  cJan-08-2015 a3264 - 32710 v53 a

Parasites comprise a significant percentage of the biodiversity of the planet and are useful systems to test evolutionary and ecological hypotheses. In this study, we analyze the effect of host species identity and the immediate local species assemblage within mixed species colonies of nesting seabirds on patterns of genetic clustering within two species of multihost ectoparasitic lice. We use three genetic markers (one mitochondrial, COI, and two nuclear, EF1-a and wingless) and maximum likelihood phylogenetic trees to test whether (1) para- sites show lineage sorting based on their host species; and (2) switching of lin- eages to the alternate host species depends on the immediate local species assemblage of individual hosts within a colony. Specifically, we examine the genetic structure of two louse species: Eidmanniella albescens, infecting both Nazca (Sula granti) and blue-footed boobies (Sula nebouxii), and Fregatiella aurifasciata, infecting both great (Fregata minor) and magnificent frigatebirds (Fregata magnificens). We found that host species identity was the only factor explaining the patterns of genetic structure in both parasites. In both cases, there is evident genetic differentiation depending on the host species. Thus, a revision of the taxonomy of these louse species is needed. One possible explana- tion of this pattern is extremely low louse migration rates between host species, perhaps influenced by fine-scale spatial separation of host species within mixed colonies, and low parasite infrapopulation numbers.

10aChewing lice10acryptic speciation10alineage sorting10aparasites10aseabirds.1 aRivera-Parra, Jose, L.1 aLevin, Iris, I.1 aJohnson, Kevin, P.1 aParker, Patricia, G. uhttp://doi.wiley.com/10.1002/ece3.2015.5.issue-16