Host-parasite relationship between the American Streblidae and the bats, with a new key to the American genera and a record of the Streblidae from Trinidad, British West Indies (Diptera)

Remarkably low host specificity in the bat fly Penicillidia fulvida (Diptera: Nycteribiidae) as assessed by mitochondrial COI and nuclear 28S sequence data

BACKGROUND

The recognition and delineation of morphologically indistinguishable cryptic species can have broad implications for wildlife conservation, disease ecology and accurate estimates of biodiversity. Parasites are intriguing in the study of cryptic speciation because unique evolutionary pressures and diversifying factors are generated by ecological characteristics of host-parasite relationships, including host specificity. Bat flies (Diptera: Nycteribiidae and Streblidae) are obligate, hematophagous ectoparasites of bats that generally exhibit high host specificity. One rare exception is Penicillidia fulvida (Diptera: Nycteribiidae), an African bat fly found in association with many phylogenetically distant hosts. One explanation for P. fulvida's extreme polyxeny is that it may represent a complex of host-specific yet cryptic species, an increasingly common finding in molecular genetic studies of supposed generalist parasites.

METHODS

A total of 65 P. fulvida specimens were collected at 14 localities across Kenya, from bat species representing six bat families. Mitochondrial cytochrome c oxidase subunit 1 (COI) and nuclear 28S ribosomal RNA (rRNA) sequences were obtained from 59 specimens and used to construct Bayesian and maximum likelihood phylogenies. Analysis of molecular variance was used to determine how genetic variation in P. fulvida was allocated among host taxa.

RESULTS

The 28S rRNA sequences studied were invariant within P. fulvida. Some genetic structure was present in the COI sequence data, but this could be more parsimoniously explained by geography than host family.

CONCLUSIONS

Our results support the status of P. fulvida as a rare example of a single bat fly species with primary host associations spanning multiple bat families. Gene flow among P. fulvida utilizing different host species may be promoted by polyspecific roosting behavior in bats, and host preference may also be malleable based on bat assemblages occupying shared roosts. The proclivity of generalist parasites to switch hosts makes them more likely to vector or opportunistically transmit pathogens across host species boundaries. Consequently, the presence of polyxenous bat flies is an important consideration to disease ecology as bat flies become increasingly known to be associated with bat pathogens.

Bat flies (Diptera: Streblidae) of phyllostomid bats (Chiroptera: Phyllostomidae) from the mountainous central region of Veracruz, Mexico

The studies of bat flies of the family Streblidae Kolenati, 1863 in Mexico have intensified in the last five years, usually providing new geographical records of species and new bats host records. Currently, the Mexican fauna of streblids is composed of 59 species, representing 26% of total global species richness. Veracruz is one of the states with a high number of species in Mexico with 69% of species recorded in the country. We sampled a total of 527 bats of four subfamilies and 12 species, collecting a total of 870 specimens of 19 species of streblids. Megistopoda proxima (Séguy, 1926) and Paratrichobius longicrus (Miranda Ribeiro, 1907) were the most abundant species in the collection and are the two species found in a higher number of bat species. We provide comments on the taxonomy and host species for bat flies, increase the species records for this state, and add new host records for some streblids, contributing to the knowledge of streblid fauna of the mountain central region of the state of Veracruz, Mexico.

Bat Flies and Their Microparasites: Current Knowledge and Distribution

Bats are the second most diverse mammalian group, playing keystone roles in ecosystems but also act as reservoir hosts for numerous pathogens. Due to their colonial habits which implies close contacts between individuals, bats are often parasitized by multiple species of micro- and macroparasites. The particular ecology, behavior, and environment of bat species may shape patterns of intra- and interspecific pathogen transmission, as well as the presence of specific vectorial organisms. This review synthetizes information on a multi-level parasitic system: bats, bat flies and their microparasites. Bat flies (Diptera: Nycteribiidae and Streblidae) are obligate, hematophagous ectoparasites of bats consisting of ~500 described species. Diverse parasitic organisms have been detected in bat flies including bacteria, blood parasites, fungi, and viruses, which suggest their vectorial potential. We discuss the ecological epidemiology of microparasites, their potential physiological effects on both bats and bat flies, and potential research perspectives in the domain of bat pathogens. For simplicity, we use the term microparasite throughout this review, yet it remains unclear whether some bacteria are parasites or symbionts of their bat fly hosts.

New Geographical Records of Bat Flies (Diptera: Streblidae) Associated With Phyllostomid Bats (Chiroptera: Phyllostomidae) in the West Highlands of Mexico

Streblidae are ectoparasites exclusive to bats and feed only on their blood. Studies on ectoparasite fauna have increased our ecological knowledge of the parasitic relationship between streblids and their bat hosts. We evaluate assemblages of phyllostomid bats and their ectoparasitic flies in three scenarios with different types of anthropogenic use: pine-oak forest, avocado orchards, and an urban park during an annual cycle in the highlands of Michoacan, Mexico. We recorded a total of 325 bats belonging to nine species in three subfamilies: Glossophaginae, Desmodontinae, and Stenodermatinae, and obtained 225 bat flies belonging to seven species. The nectivorous bat Anoura geoffroyi Gray, 1838, had the highest prevalence of infestation and the hematophagous bat Desmodus rotundus (É. Geoffroy, 1810) was the host with the highest mean parasite abundance and mean intensity. Aspidoptera delatorrei Wenzel, 1966, Megistopoda proxima (Séguy, 1926), Paratrichobius longicrus (Miranda Ribeiro, 1907), Trichobius brennani Wenzel, 1966, and T. parasiticus Gervais, 1844, are new records for the state of Michoacan reported in this study.

Relationships among different facets of host specificity in three taxa of haematophagous ectoparasites

Host specificity is a fundamental trait of a parasite species. Recently, multiple aspects of host specificity have been recognized, but the relationships between these facets are still poorly understood. Here, we studied pairwise relationships between basic, structural, phylogenetic and geographic host specificity in three taxa of haematophagous ectoparasitic arthropods that differ in tightness of their association with the host. We asked which metrics of host specificity are correlated within each parasite taxon and whether the patterns of the association between different facets of host specificity are similar among parasite taxa. Data on bat flies were taken from published surveys across the Neotropics while data on fleas and mites parasitic on small mammals were compiled from multiple published surveys across the Palaearctic. Basic, structural, phylogenetic and geographic specificity indices were calculated for 18 bat fly species recorded on 40 host species from 15 regions, 109 flea species recorded on 120 host species from 51 regions and 34 mite species recorded on 67 host species from 28 regions. Then, we tested for the correlation between any two measures of host specificity using model II regressions. We found that structural and basic specificity, as well as structural and geographic specificity, exhibited a positive association in all three taxa. However, basic and geographic specificity, as well as basic and phylogenetic specificity, were significantly positively associated in fleas but did not correlate in bat flies or mites. In addition, we found a significant negative association between structural and phylogenetic specificity in bat flies but no association in the remaining taxa. Moreover, geographic and phylogenetic specificity were not associated in any parasite taxon. Our results suggest that different facets of host specificity were shaped differently by natural selection in different taxa.

Bat flies (Diptera: Nycteribiidae and Streblidae) infesting cave-dwelling bats in Gabon: diversity, dynamics and potential role in Polychromophilus melanipherus transmission

Background

Evidence of haemosporidian infections in bats and bat flies has motivated a growing interest in characterizing their transmission cycles. In Gabon (Central Africa), many caves house massive colonies of bats that are known hosts of Polychromophilus Dionisi parasites, presumably transmitted by blood-sucking bat flies. However, the role of bat flies in bat malaria transmission remains under-documented.

Methods

An entomological survey was carried out in four caves in Gabon to investigate bat fly diversity, infestation rates and host preferences and to determine their role in Polychromophilus parasite transmission. Bat flies were sampled for 2–4 consecutive nights each month from February to April 2011 (Faucon and Zadie caves) and from May 2012 to April 2013 (Kessipoughou and Djibilong caves). Bat flies isolated from the fur of each captured bat were morphologically identified and screened for infection by haemosporidian parasites using primers targeting the mitochondrial cytochrome b gene.

Results

Among the 1,154 bats captured and identified as Miniopterus inflatus Thomas (n = 354), Hipposideros caffer Sundevall complex (n = 285), Hipposideros gigas Wagner (n = 317), Rousettus aegyptiacus Geoffroy (n = 157, and Coleura afra Peters (n = 41), 439 (38.0 %) were infested by bat flies. The 1,063 bat flies recovered from bats belonged to five taxa: Nycteribia schmidlii scotti Falcoz, Eucampsipoda africana Theodor, Penicillidia fulvida Bigot, Brachytarsina allaudi Falcoz and Raymondia huberi Frauenfeld group. The mean infestation rate varied significantly according to the bat species (ANOVA, F_(4,75) = 13.15, P < 0.001) and a strong association effect between bat fly species and host bat species was observed. Polychromophilus melanipherus Dionisi was mainly detected in N. s. scotti and P. fulvida and less frequently in E. africana, R. huberi group and B. allaudi bat flies. These results suggest that N. s. scotti and P. fulvida could potentially be involved in P. melanipherus transmission among cave-dwelling bats. Sequence analysis revealed eight haplotypes of P. melanipherus.

Conclusions

This work represents the first documented record of the cave-dwelling bat fly fauna in Gabon and significantly contributes to our understanding of bat fly host-feeding behavior and their respective roles in Polychromophilus transmission.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1625-z) contains supplementary material, which is available to authorized users.

Streblidae (Diptera: Hippoboscoidea) from Yucatan and Updated Species List for Mexico

This study describes the diversity of ectoparasitic bat flies (Diptera: Streblidae) in the state of Yucatan, Mexico. Fieldwork was carried out from June 2010 to January 2012 in seven municipalities of Yucatan, where 13 sampling sites were selected to capture bats using mist nets. Over 156 sampling nights a total of 910 bats were captured; these belonged to 19 species in four families: Mormoopidae, Phyllostomidae, Natalidae, and Vespertilionidae. Phyllostomidae was the richest family (13 bat species), followed by Mormoopidae (3 spp.), Vespertilionidae (2 spp.), and Natalidae (1 spp.). After careful inspection of the bats, a total of 2,134 Streblid bat flies were collected, belonging to 17 species in six genera (Nycterophilia coxata Ferris, N. natali Wenzel, Trichobius diphyllae Wenzel, T. dugesii Townsend, T. galei Wenzel, T. hirsutulus Bequaert, T. intermedius Peterson and Hurka, T. parasiticus Gervais, T. uniformis Curran, T. yunkeri Wenzel, Megistopoda aranea Coquillett, M. proxima Séguy, Aspidoptera delatorrei Wenzel, Strebla alvarezi Wenzel, S. diphyllae Wenzel, S. wiedemanni Kolenati, and Metelasmus pseudopterus Coquillett). The richest and most diverse genus was Trichobius. Five species--N. natali, T. diphyllae, M. proxima, A. delatorrei, and M. pseudopterus, are new records for Yucatan, and T. galei is a new record for the country, increasing the total number of Streblidae species for Mexico to 49.

Genetic signature of reproductive manipulation in the phylogeography of the bat fly, Trichobius major

The bat fly (Trichobius major) is a blood-feeding ectoparasite of the cave myotis (Myotis velifer). A recent mitochondrial DNA (mtDNA) study examining population structure of T. major in the South Central United States detected a single haplotype from all individuals examined (N = 48 from 12 different caves), representing one of only a few known examples of such widespread mtDNA uniformity. We examined nuclear genetic diversity using amplified fragment length polymorphism and detected high levels of nuclear genetic diversity in all populations sampled. Amplified fragment length polymorphism analyses indicated significant levels of gene flow among caves >700 km apart, suggesting the absence of mtDNA diversity in T. major is the result of a selective sweep, not a demographic event (i.e., a recent bottleneck). One mechanism by which mtDNA sweeps occur in arthropods is through bacterial parasites that manipulate host reproduction and mtDNA inheritance. We used PCR to test for the presence of all known reproductive parasites and detected a widespread infection (91.33% infection rate) of T. major with a novel Arsenophonus bacterium, as well as the infection of 2 individuals (1.16% infection rate) with a novel strain of Rickettsia. We discuss the implications for T. major phylogeography and the necessity of a bigenomic approach in arthropod population genetics.

Description of two new species of Ascodipteron from africa and one species of Nycteribosca from madagascar (Diptera, streblidae)

The description of one new species of Ascodipteron and another one of Nycteribosca is based on the material collected in Africa and Madagascar respectively by Mr H. Hoogstraal, of the United States Naval Medical Research Unit No. 3. These specimens represent a part of the collection which was sent to me for identification by Mr R. L. Wenzel of the Chicago Natural History Museum. In this paper I have also included the description of another new species of Ascodipteron of which two specimens were collected by Mr T. S. Jones in West Africa.

JO. Host and host-site specificity of bat flies (Diptera: Streblidae and Nycteribiidae) on Neotropical bats (Chiroptera)

Ectoparasite host specificity can be influenced by factors such as the degree of host isolation and ectoparasite mobility. Host-site specificity can result from factors such as proximity to mates, competition, and host grooming behaviour. Ectoparasitic bat flies on bats from the Lamanai area of Belize were collected from hosts captured in mist nets to determine host specificity and host-site specificity. Bat grooming behaviour was also recorded and quantified. From 455 bats (25 species in five families), 773 bat flies (32 species in two families) were collected. Of 32 bat fly species, 25 were only found on 1 bat species, 6 were found on 2 species of the same genus, and 1 was found on 2 species of different genera (the latter appearing to be an accidental association). Specificity of the bat flies tended to follow the taxonomy of the bat hosts, not the ecological isolation of the host species, since bat species that often roost in polyspecific groups did not share bat fly species. Mobility of the bat flies was not related to host specificity. Host-site specificity of bat flies occurred for either fur or membrane on the host, and long hind legs and ctenidia appear to be morphological adaptations for living in fur. Bat grooming behaviour was consistent with the assumptions of a simulation model, which suggested that host grooming could be responsible for host-site segregation of bat flies.