Daniel R. Gustafsson

Genetic variation in the popular lab worm Lumbriculus variegatus (Annelida: Clitellata: Lumbriculidae) reveals cryptic speciation

Genetic variation in the freshwater oligochaete Lumbriculus variegatus from Europe, North America and Japan was studied by sequencing and analysing the mitochondrial 16S and COI genes, and the nuclear ITS region. What hitherto has been regarded as L. variegatus was found to consist of at least two distinct clades (I and II), both of which occur in Europe as well as North America (clade I also in Japan). Specimens from a single locality in Sierra Nevada, California, also morphologically identified as L. variegatus, represent a third clade, which appears to be more closely related to clade II than to clade I, based on 16S data only. Average COI genetic distances were 17.7% between clades I and II, 0.6% within clade I, and 1.3% within clade II. Further, for these two clades, the mitochondrial (16S and COI) gene trees, which consider only the maternal lineages, are congruent with the ITS gene tree, which is the result of recombinations of paternal as well as maternal genomes. Finally, chromosome counts revealed clade I specimens to be highly polyploid, and clade II specimens to be diploid. We therefore conclude that clades I-II are separately evolving lineages, and that they should be regarded as separate species. This will have to be taken into account in the continued use of L. variegatus as a model organism in biological sciences.

Unlocking the black box of feather louse diversity: A molecular phylogeny of the hyper-diverse genus Brueelia

Songbirds host one of the largest, and most poorly understood, groups of lice: the Brueelia-complex. The Brueelia-complex contains nearly one-tenth of all known louse species (Phthiraptera), and the genus Brueelia has over 300 species. To date, revisions have been confounded by extreme morphological variation, convergent evolution, and periodic movement of lice between unrelated hosts. Here we use Bayesian inference based on mitochondrial (COI) and nuclear (EF-1α) gene fragments to analyze the phylogenetic relationships among 333 individuals within the Brueelia-complex. We show that the genus Brueelia, as it is currently recognized, is paraphyletic. Many well-supported and morphologically unified clades within our phylogenetic reconstruction of Brueelia were previously described as genera. These genera should be recognized, and the erection of several new genera should be explored. We show that four distinct ecomorphs have evolved repeatedly within the Brueelia-complex, mirroring the evolutionary history of feather-lice across the entire order. We show that lice in the Brueelia-complex, with some notable exceptions, are extremely host specific and that the host family associations and geographic distributions of these lice are significantly correlated with our understanding of their phylogenetic history. Several ecological phenomena, including phoresis, may be responsible for the macroevolutionary patterns in this diverse group.

Flyway homogenisation or differentiation? Insights from the phylogeny of the sandpiper (Charadriiformes: Scolopacidae: Calidrinae) wing louse genus Lunaceps (Phthiraptera: Ischnocera).

The wing louse genus Lunaceps, is the most speciose chewing louse (Phthiraptera) genus inhabiting sandpipers (Charadriiformes: Calidrinae) and is known from almost all sandpiper species. The hosts follow specific flyways from the Arctic breeding grounds to wintering locations in the southern hemisphere, and often form large mixed-species flocks during migration and wintering. We estimated a phylogeny of Lunaceps based on three mitochondrial loci, supporting monophyly of the genus but revealing extensive paraphyly at the species level. We also evaluated the relative importance of flyway differentiation (same host species having different lice along different flyways) and flyway homogenisation (different host species having the same lice along the same flyway). We found that while the lice of smaller sandpipers and stints show some evidence of flyway homogenisation, those of larger sandpipers do not. No investigated host species migrating along more than one flyway showed any evidence of flyway differentiation. The host-parasite associations within Lunaceps are in no case monophyletic, rejecting strict cospeciation.

Remarkable levels of avian louse (Insecta: Phthiraptera) diversity in the Congo Basin

Although the Democratic Republic of the Congo is considered a megadiverse country, the Congo Basin is not recognized as a conservation priority because of gross underestimates of species diversity and endemism, especially for invertebrate taxa. Examining ectoparasitic chewing lice parasitizing birds in this region could provide valuable information pertaining to the diversity of invertebrate taxa as well as host–parasite interactions within the Congo Basin. In this study, we used molecular and morphological data to examine avian louse diversity. From 60 parasitized birds, we documented 39 new host associations, and at least 12 and 17 species of amblyceran and ischnoceran chewing lice, respectively. Morphologically, we identified a minimum of 13 new species. Due to a lack of available reference material, we were unable to identify some specimens and it is likely many, if not all of these, represent new species. Our sampling efforts, morphological examinations and molecular analyses reveal an astounding amount of louse diversity in the Congo Basin.

Patterns of cryptic host specificity in duck lice based on molecular data

Documenting patterns of host specificity in parasites relies on the adequate definition of parasite species. In many cases, parasites have simplified morphology, making species delimitation based on traditional morphological characters difficult. Molecular data can help in assessing whether widespread parasites harbour cryptic species and, alternatively, in guiding further taxonomic revision in cases in which there is morphological variation. The duck louse genus Anaticola (Phthiraptera: Philopteridae), based on current taxonomy, contains both host‐specific and widespread species. Mitochondrial and nuclear DNA sequences of samples from this genus were used to document patterns of host specificity. The comparison of these patterns with morphological variations in Anaticola revealed a general correspondence between the groups identified by DNA sequences and morphology, respectively. These results suggest that a more thorough taxonomic review of this genus is needed. In general, the groups identified on the basis of molecular data were associated with particular groups of waterfowl (e.g. dabbling ducks, sea ducks, geese) or specific biogeographic regions (e.g. North America, South America, Australia, Eurasia).

Four new species of Brueelia Kéler, 1936 (Phthiraptera: Ischnocera: Philopteridae) from African songbirds (Passeriformes: Sturnidae and Laniidae).

Four new species in the louse genus Brueelia Kéler, 1936 are described from African hosts of the families Sturnidae and Laniidae. They are: Brueelia rigbyi n. sp. ex Corvinella melanoleuca (Jardine, 1831), B. clara n. sp. ex Lamprotornis australis (A. Smith, 1836), B. tkachi n. sp. ex Spreo albicapillus albicapillus Blyth, 1856, and B. coryliventer n. sp. ex Creatophora cinerea (Meuschen, 1787). These four species are characterized by a unique abdominal chaetotaxy and a sinuous thickening of the distal margin of the male mesosome. These four species are very similar, and we consider them to form one species group. A key to the species of the group is provided.

The Chewing Lice (Insecta: Phthiraptera: Ischnocera: Amblycera) of Japanese Pigeons and Doves (Columbiformes), with Descriptions of Three New Species

Abstract:  The chewing louse fauna of pigeons and doves in Japan is reviewed based on published records and new collections. An updated checklist of the chewing lice of Japanese pigeons and doves is provided, and 3 new species are described: Columbicola asukae n. sp. and Coloceras nakamurai n. sp., both from Columba janthina Temminck, 1830 (Japanese wood pigeon), and Columbicola lemoinei n. sp. from Treron formosae permagnus Stejneger, 1887, and Treron formosae medioximus (Bangs, 1901) (whistling green-pigeons). This checklist includes data on the first records of Coloceras chinense (Kellogg and Chapman, 1902), Coloceras piriformis (Tendeiro, 1969), and Columbicola guimaraesi Tendeiro, 1965, in Japan. New host records of Hohorstiella sp. from Columba janthina and Treron formosae permagnus, and Coloceras sp. from Treron sieboldii sieboldii (Temminck, 1835) (white-bellied green-pigeon) are provided.

Data supporting a molecular phylogeny of the hyper-diverse genus Brueelia

Data is presented in support of a phylogenetic reconstruction of one of the largest, and most poorly understood, groups of lice: the Brueelia-complex (Bush et al., 2015[1]). Presented data include the voucher information and molecular data (GenBank accession numbers) of 333 ingroup taxa within the Brueelia-complex and 30 outgroup taxa selected from across the order Phthiraptera. Also included are phylogenetic reconstructions based on Bayesian inference analyses of combined COI and EF-1α sequences for Brueelia-complex species and outgroup taxa.

Two new species of Paraphilopterus Mey, 2004 (Phthiraptera: Ischnocera: Philopteridae) from New Guinean bowerbirds (Passeriformes: Ptilonorhynchidae) and satinbirds (Passeriformes: Cnemophilidae)

Two new species of Paraphilopterus Mey, 2004 are described and named. Paraphilopterus knutieae n. sp. is described from two subspecies of Macgregors bowerbirds: Amblyornis macgregoriae nubicola Schodde & McKean, 1973 and A. m. kombok Schodde & McKean, 1973, and Sanfords bowerbird: Archboldia sanfordi (Mayr & Gilliard, 1950) (Ptilonorhynchidae). Paraphilopterus meyi n. sp. is described from two subspecies of crested satinbirds: Cnemophilus macgregorii macgregorii De Vis, 1890 and C. m. sanguineus Iredale, 1948 (Cnemophilidae). These new louse species represent the first records of the genus Paraphilopterus outside Australia, as well as from host families other than the Corcoracidae. The description of Paraphilopterus is revised and expanded based on the additional new species, including the first description of the male of this genus. Also, we provide a key to the species of Paraphilopterus.

Unexpected distribution patterns of Carduiceps feather lice (Phthiraptera: Ischnocera: Philopteridae) on sandpipers (Aves: Charadriiformes: Scolopacidae)

The louse genus Carduiceps Clay & Meinertzhagen, 1939 is widely distributed on sandpipers and stints (Calidrinae). The current taxonomy includes three species on the Calidrinae (Carduiceps meinertzhageni, Carduiceps scalaris, Carduiceps zonarius) and four species on noncalidrine hosts. We estimated a phylogeny of four of the seven species of Carduiceps (the three mentioned above and Carduiceps fulvofasciatus) from 13 of the 29 hosts based on three mitochondrial loci, and evaluated the relative importance of flyway differentiation (same host species has different lice along different flyways) and flyway homogenization (different host species have the same lice along the same flyway). We found no evidence for either process. Instead, the present, morphology‐based, taxonomy of the genus corresponds exactly to the gene‐based phylogeny, with all four included species monophyletic. Carduiceps zonarius is found both to inhabit a wider range of hosts than wing lice of the genus Lunaceps occurring on the same group of birds, and to occur on Calidris sandpipers of all sizes, both of which are unexpected for a body louse. The previously proposed family Esthiopteridae is found to be monophyletic with good support. The concatenated dataset suggests that the pigeon louse genus Columbicola may be closely related to the auk and diver louse genus Craspedonirmus. These two genera share some morphological characters with Carduiceps, but no support was obtained for grouping these three genera together. Based on mitochondrial data alone, the relationships among genera within this proposed family cannot be properly assessed, but some previously suggested relationships within this proposed family are confirmed.