Donald Gettinger

A FAUNAL SURVEY OF STREBLID FLIES (DIPTERA: STREBLIDAE) ASSOCIATED WITH BATS IN PARAGUAY

An extensive survey of the ectoparasites infesting bats in Paraguay provides information regarding the taxonomy and host distribution of streblid bat flies at a geographic interface between subtropical and temperate habitats. Five families of bats representing 45 species, including Molossidae (5 genera and 15 species), Natalidae (1 genus and 1 species), Phyllostomidae (11 genera and 15 species), Noctilionidae (1 genus and 2 species), and Vespertilionidae (4 genera and 12 species) were collected from 24 localities across Paraguay and sampled for ectoparasites. In total, 2,467 bat flies were collected, representing 11 genera and 31 nominal species of Streblidae, of which 6 genera and 24 species are new records for Paraguay. No streblids were collected from vespertilionid bats; 23 species infested phyllostomids, 6 species noctilionids, 1 species a natalid, and 1 species molossids. Streblid bat flies were highly specific to certain host groups and individual host species, and their geographic distributions closely followed those of their host bats. Of 31 streblid species surveyed, 27 were monoxenous (i.e., associated with a single host species), and 4 were stenoxenous (i.e., associated with a group of phylogenetically related hosts). The number of streblid species is greatly reduced in the Chaco region west of the Paraguay River, largely because of the lack of phyllostomid host bats.

ECOLOGY AND HOST SPECIFICITY OF LAELAPINE MITES (ACARI: LAELAPIDAE) OF SMALL MAMMALS IN AN ATLANTIC FOREST AREA OF BRAZIL

Mesostigmatic mites of the Laelapinae Berlese, 1892 (Acari: Laelapidae) are nidicolous arthropods that commonly occur in the fur of Neotropical small mammmals. In this 2-yr study, the laelapine acarofauna associated with the small mammal community in an area of Atlantic forest on Ilha Grande, Rio de Janeiro State, was examined, including observations on patterns of host specificity, mite dispersal, ecology, and food habits. A total of 1,347 laelapines was sampled from the pelage of 6 species of small mammals (Marmosops incanus, Nectomys squamipes, Oryzomys russatus, Rhipidomys n. sp., Oxymycterus dasytrichus, and Trinomys dimidiatus), all of which occurred exclusively in monoxenous associations with their hosts. No evidence of a blood meal was observed in the gut of the mites. With the exception of the 2 species of Tur, mite populations on hosts were entirely or nearly restricted to adult females. These results, together with some morphological characteristics of laelapines, reinforce the hypotheses that Neotropical laelapine mites are not ectoparasitic, and that females disperse by phoresy.

A method for testing the host specificity of ectoparasites: give them the opportunity to choose

Host-choice experiments were carried out with rodent and bat ectoparasites on Ilha Grande, state of Rio de Janeiro, Brazil. We constructed experimental chambers that enclosed three different rodent or bat host species, and then introduced a selected set of ectoparasitic arthropods. When given the opportunity to choose among host species, the ectoparasites showed a strong tendency to select their primary hosts, and reject novel host species. These kinds of simple experiments can be valuable tools for assessing the ability of ectoparasites to locate and discern differences between host species, and make choices about which hosts to infest, and which hosts to avoid.

Assessing host specificity of obligate ectoparasites in the absence of dispersal barriers

Host specificity is a characteristic property of parasite-host associations and often is high among those involving obligate or permanent parasites. While many parasites are highly host-specific under natural conditions, specificity may break down in the absence of dispersal barriers. We tested the host specificity of obligate and permanent blood-feeding bat parasites (Hemiptera: Polyctenidae) under experimental conditions where parasite dispersal barriers had been removed. Under these conditions, parasites not only readily accepted a secondary host species but also remained there when a primary host was immediately available. Experiments with bat bugs and observations of streblid bat flies suggest that specificity may at least temporarily break down when dispersal barriers are removed. To affect long-term coevolutionary patterns, such transfers would necessarily entail the establishment of viable parasite populations on secondary host species.

Bolivian Ectoparasites: A Survey of Bats (Mammalia Chiroptera)

Abstract A survey collection of arthropods associated with bats documents new distributional records of Bolivian ectoparasites. New species records include Acari: Mesostigmata: Spinturnicidae—Periglischrus caligus Kolenati, Periglischrus iheringi Oudemans, Periglischrus ojasti Machado-Allison; Macronyssidae—Radfordiella oudemansi Fonseca; Metastigmata: Argasidae—Ornithodoros hasei (Schulze); Insecta: Diptera: Streblidae—Anastrebla caudiferae Wenzel, Anastrebla modestini Wenzel, Anatrichobius scorzai Wenzel, Exastinion deceptivum Wenzel, Megistopoda theodori Wenzel, Neotrichobius delicatus (Machado-Allison), Paradyschiria fusca Speiser, Paraeuctenodes similis Wenzel, Strebla curvata Wenzel, Strebla guajiro (García & Casal), Trichobius petersoni Wenzel, and Trichobius tiptoni Wenzel.

LAELAPINE MITES (ACARI: LAELAPIDAE) ASSOCIATED WITH SMALL MAMMALS FROM AMAZONAS, BRAZIL , INCLUDING A NEW SPECIES FROM MARSUPIALS

An intensive survey of ectoparasitic arthropods associated with small mammals in upland forests near Manaus, Brazil, provides information on the taxonomy and host distribution of laelapine mites in the Amazonian Region. We identified 5 genera and 21 species of these mites by comparison with representative museum specimens, the taxonomic literature, and, when possible, the original type specimens. These mites are host specific, with associations ranging from strict monoxeny (18 species) to oligoxeny (1 species) and pleioxeny (2 species). Marsupials were infested with species of Androlaelaps, echimyid rodents with Tur, and sigmodontine rodents with Gigantolaelaps, Laelaps, and Mysolaelaps. Androlaelaps bergalloi, a new species of Laelapinae, is described from the pelage of the marsupial Monodelphis brevicaudata.

Host associations between laelapine mites (Mesostigmata: Laelapidae) and palustrine rodents in Paraguay: a study of host specificity and cryptic species

Abstract Host specialization has contributed to the high diversity of laelapine mites associated with Neotropical rodents, but the lack of taxonomic development at the species-level has confounded study of the coevolutionary history of both host and ectoparasite groups. Morphometric comparisons of presumptive polyxenous laelapine species infesting a diverse assemblage of palustrine rodents in Paraguay clearly reveal that each host species is infested by a morphologically distinct mite population. The nominal taxa Laelaps manguinhosi, Gigantolaelaps goyanensis, and G. mattogrossensis may be composites of morphologically distinct but similar species with narrower host preferences. These results suggest that laelapine mites are primarily monoxenous, and that numerous currently unrecognized species may be discerned by standard morphometric techniques.

Hesperoctenes fumarius (Hemiptera: Polyctenidae) Infesting Molossus rufus (Chiroptera: Molossidae) in Southeastern Brazil

We analyzed the prevalence, intensity, and medium density of parasitism of Hesperoctenes fumarius infesting Molossus rufus in natural (hollow trees) and anthropogenic roosts (attics) in southeastern Brazil. The prevalence and intensity of infestations were higher in the hollow trees than in the attic roosts. We also noted a relationship between the amount of space available within the roost and the infestation levels of H. fumarius. One advantage of roosting in larger, often man-made, refuges may be the reduction in ectoparasite infestations.

A new species of Androlaelaps (Acari: Parasitiformes) from the akodontine rodent Deltamys kempi Thomas, 1919, in La Plata River Basin, Argentina.

Abstract Androlaelaps maurii, a new species of laelapine mite, is described on the basis of female specimens collected from the pelage of the akodontine rodent, Deltamys kempi, from La Plata River basin in Argentina. Androlaelaps maurii can be differentiated from closely related species by its smaller size, the differing distribution of setae in the dorsal shield, and an unarmed opithogaster. This mite appears to be host specific to D. kempi and occurs on this rodent throughout its distribution in Argentina and Uruguay.

Androlaelaps marmosops (Acari: Laelapidae), a new species associated with the mouse opossum, Marmosops incanus (Lund, 1840) in the Atlantic Forest of Rio de Janeiro State, Brazil

Androlaelaps marmosops, a new species of laelapid mite, is described from the pelage of the mouse opossum, Marmosops incanus (Lund, 1840) (Mammalia: Didelphidae), in two areas of Atlantic Forest of Rio de Janeiro State. Measurements and illustrations are included for females only.