Gregarina triboliorum (Eugregarinida: Gregarinidae) n. sp. from Tribolium confusum and resolution of the confused taxonomic history of Gregarina minuta Ishii, 1914.
ABSTRACT The septate gregarine parasites of flour beetles (Tribolium spp.) include Gregarina minuta Ishii, 1914, a relatively small species in which both primite and satellite possess an obvious protomerite, and a larger species that lacks the satellite protomerite. The latter species has been placed in the genera Didymophyes and Hirmocystis by various authors, but studies reported here demonstrate that this species, herein described as Gregarina triboliorum, exhibits early pairing and produces oocyst chains, both characteristics of the genus Gregarina. The oocysts of this new species are described for the first time. In addition, experimental infections using oocyst from single gametocysts reveal that oocyst chain number is variable but is typically 1, 2, or 4. Prior experiments involving a related beetle, Tenebrio molitor, demonstrated extreme host specificity within the 4 Gregarina species parasitizing larval and adult hosts. However, G. triboliorum is not limited either stadially or specially, infecting both adults and larvae of Tribolium confusum and Tribolium castaneum.
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ABSTRACT: Gregarine host specificity has been the cornerstone of gregarine taxonomy for nearly a century. Several laboratory experiments have accepted strict host specificity by failure to cross-infect distantly related hosts with unrelated gregarine species. These empirical studies are not feasible for all gregarine hosts, especially nondomesticated groups. Additionally, studies of gregarine distributions have always focused on insect hosts of disparate groups, rather than targeting potential hosts species within a single genus and their congeneric gregarines. This study addresses host utilization of nubenocephalid gregarines parasitizing the odonate genus Argia (Odonata: Zygoptera: Coenagrionidae). Populations of 9 species of adult Argia were collected, dissected, and observed for gregarine infection during the April–September flight seasons in 2007 from 17 localities in the central United States. On average, 2.5 species of Argia were collected at each locality. A species of Nubenocephalus—Nubenocephalus nebraskensis, Nubenocephalus secundus, or Nubenocephalus spp.—was collected from every infected population of Argia except for the Argia vivida population at Prairie Dog Town Fork-Red River, Randall County (Co.), Texas, U.S.A. Nubenocephalus secundus utilizes at least 7 of the 9 argid hosts sampled whereas N. nebraskensis was collected from only 2 argid species. Only Argia translata was observed to host both N. secundus and N. nebraskensis. These patterns of host utilization by nubenocephalid gregarines represent an ecotypic gregarine assemblage rather than a vicariant assemblage, demonstrating that nubenocephalid gregarines do not differentiate between species of Argia as hosts.Comparative Parasitology 01/2011; · 0.88 Impact Factor
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ABSTRACT: Protomagalhaensia cerastes n. sp. is described from nymphs and adults of the Pallid cockroach, Phoetalia pallida. Gamonts of Protomagalhaensia species are elongate and serpentine in general shape, but associated gamonts of P. cerastes are considerably smaller than those of other species of Protomagalhaensia. Primites and satellites of P. cerastes average total lengths of 323.1 µm and 317.9 µm, respectively; whereas similar stages range from 400.0 µm to 650.0 µm in the other 4 species within the genus. All species of Protomagalhaensia possess dolioform oocysts. Oocysts of Protomagalhaensia granulosae and Protomagalhaensia serpentula also possess apical corner spines or knobs that are absent in the oocysts of Protomagalhaensia wolfi, Protomagalhaensia blaberae, and P. cerastes. The oocysts of P. granulosae possess a lateral depression unique among members of the genus, while P. cerastes and P. wolfi possess distinct polar plates absent in other members of the genus. Oocysts of P. cerastes are notably smaller than those of P. wolfi in both length (7.3 µm vs. 9.2 µm) and width (4.5 µm vs. 5.5 µm).Comparative Parasitology 07/2010; · 0.88 Impact Factor
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ABSTRACT: A phylogenetic hypothesis was constructed with the use of ssu rDNA sequence data from 27 eugregarine species parasitizing a variety of arthropod hosts and habitats. The data were used to address higher-level character transitions, identify clades, recognize supraspecific taxonomic groups, assess the existing gregarine classification, and assess the effects of host metabolic pattern and habitat transitions on the radiation of the septatorinid gregarines. Suprageneric character transitions for association form, association timing, syzygy, gametocyst dehiscence, and oocyst liberation are defined. New character search based on the proposed phylogeny produced a morphological character set that correlates strongly with the sequence data. These morphological character sets are mapped to the new septatorinid phylogeny. Existing superfamily groups within Septatorina were recovered and a new superfamily recognized. At the family level, the monophyly of Actinocephalidae and Stylocephalidae is confirmed and the polyphyly of Gregarinidae is partially resolved with the recognition of Blabericolidae. At the generic level, the monophyly of Protomagalhaensia and Xiphocephalus is confirmed, the polyphyly of Leidyana is partially resolved with the recognition of Blabericola, and the polyphyly of Gregarina is revealed but cannot be resolved without additional taxonomic data. High-level diversification of Septatorina resulted from adaptations of the gametocyst, allowing colonization of both terrestrial and sweet-water habitats. Major radiations within the group correlate with host metamorphic pattern, suggesting that evolutionarily, gregarine species track niche resources along lines of transmission; they do not necessarily track host species in evolutionary time. Gregarine assemblages within a single host species may be either vicariant assemblages, (i.e., products of coevolutionary, phylogenetic effects), or ecotypic assemblages, (i.e., products of ecological fitting and host switching). The following systematic or nomenclatural acts are committed. Stenophoroidea and Gregarinoidea are emended. Diagnoses of Stenophoroidea, Gregarinoidea, and Sphaerocystidae are revised. Stylocephaloidea n. supfam., Blabericolidae n. fam., and Blabericola n. gen. are recognized and erected. Blabericola princisi n. comb., Blabericola cubensis n. comb., Blabericola haasi n. comb., and Blabericola migrator n. comb. are recognized. Schneideria, Neoschneideria, and Paraschneideria are removed from Sphaerocystidae and placed in Actinocephalidae. Protomagalhaensia is removed from Hirmocystidae and placed in Blabericolidae. Pyxinia is removed from Stylocephaloidea: Actinocephalidae and placed in Stenophoroidea: Monoductidae. Blabericola haasi, Blabericola migrator, Blabericolidae, Colepismatophila watsonae, Eugregarinorida, Geneiorhynchus manifestus, Gregarina basiconstrictonea, Gregarina blattarum, Gregarina coronata, Gregarina cuneata, Gregarina diabrotica, Gregarina kingi, Gregarina niphandrodes, Gregarina polymorpha, Gregarina tropica, Gregarine, Gregarinidae, Gregarinoidea, Hirmocystidae, Hoplorhynchus acanthatholius, Leidyana erratica, Monoductidae, Neoschneideria, Paraschneideria, Paraschneideria metamorphosa, phylogeny, Prismatospora evansi, Protomagalhaensia, Protomagha- lensia granulosae, Protomaghalensia wolfi, Pyxinia crystalligera, Schneideria, Septatorina, Sphaerocystidae, Stenophora robusta, Stenophoroidea, Stylocephalidae, Stylocephaloidea, Stylocephalus giganteus, Xiphocephalus ellisi, Xiphocephalus triplogemmatus.Comparative Parasitology 08/2009; · 0.88 Impact Factor