Tamara J. Cook
Sam Houston State University
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Environmental Entomology | 2002
Tamara J. Cook
Abstract Surveys were conducted at four Texas Army National Guard training facilities to assess the natural distribution and prevalence of Thelohania solenopsae Knell, Allen and Hazard infection in polygynous imported fire ants, Solenopsis invicta Buren. T. solenopsae was found at three of the four training facilities; intercolonial prevalence ranged from 9 to 47%, and worker prevalence ranged from 0.15 to 0.57. A plot containing fire ants infected with T. solenopsae at one of the training facilities was monitored for 2 yr to determine whether natural infection rates fluctuate over time, whether infection affects colony size, as indicated by mound volume, and whether there was a relationship between climate and infection prevalence. At this site, intercolonial prevalence ranged from a high of 47% in July 1999 to a low of 11% in October 2000, and mean worker prevalence ranged from 0.20 to 0.57. Mound volume of infected colonies was consistently less than the volume of uninfected colonies. There was no correlation between temperature or precipitation and proportion of infected colonies, but there was a positive correlation between colony density and percentage of infection with T. solenopsae.
Journal of Parasitology | 2004
Richard E. Clopton; Tamara J. Cook; J. L. Cook
Naiadocystis phykoterion n. gen., n. sp. (Apicomplexa: Eugregarinida: Hirmocystidae), is described from the Mexican pygmy grasshopper, Paratettix mexicanus (Orthoptera: Tetrigidae), collected from sandbars along Harmon Creek, Walker County, Texas, in the western edge of the Texas Big Thicket. Naiadocystis n. gen. is distinguished by the form of the epimerite complex, a simple cordoid or toroid epimerite with an interior obconoid structure resembling a funnel that tapers to a distinct axial canal bisecting the protomerite, which is conspicuous in all stages of development, and a satellite protomerite reduced to a linearly crateriform cup or sucker that receives and enfolds posterior end of primite deutomerite. Association is precocious, caudofrontal, and biassociative. Gametocysts are spherical. Sporoducts are present but vestigial and irregular in number. Oocysts are broadly elliptoid with 4 small spherical polar knobs, 1 each at 30°, 150°, 210°, and 330°, and dehisce en masse. The species described herein are differentiated by their overall size and relative proportion of cellular structures. Naiadocystis acantholobae (Hoshide, 1952) n. comb., Naiadocystis acrydiinarum (Semans, 1939) n. comb., and Naiadocystis tetrigis (Corbel, 1968) n. comb. are recognized as members of Naiadocystis previously placed within Gregarina (Apicomplexa: Eugregarinida: Gregarinidae).
Comparative Parasitology | 2007
Joanna Hays; Richard E. Clopton; Tamara J. Cook; Jerry L. Cook
Abstract Nubenocephalus secundus n. sp. (Apicomplexa: Eugregarinida) is described from adults of Argia sedula (Odonata: Zygoptera: Coenagrionidae) collected from Harmon Creek, Sam Houston State University Center for Biological Field Studies, Walker County, Texas, U.S.A. This is the second species described in the genus and confirms the generic hypothesis of Nubenocephalus. The generic diagnosis of Nubenocephalus is revised to reflect common characters of its constituent species and a previously described Asian gregarine, Nubenocephalus mutabilis n. comb. (=Ancyrophora mutabilis) is recognized as a member of the genus.
Comparative Parasitology | 2007
Richard E. Clopton; Tamara J. Cook; Jerry L. Cook
Abstract Geneiorhynchus manifestus n. sp. (Apicomplexa: Eugregarinida) is described from the naiads of Anax junius (Odonata: Aeshnidae) collected from the Big Sandy Creek Unit of the Big Thicket National Preserve, Polk County, Texas, U.S.A. The genus Geneiorhynchus is revised and its constituent species reviewed. Descriptions are provided for 2 previously named species, Geneiorhynchus monnieri from naiads of Libellula depressa (Odonata: Libellulidae) collected from Bayreuth, Germany and Roscoff, France and Geneiorhynchus aeshnae from naiads of Aeshna constricta and Aeshna sp. (Odonata: Aeshnidae) collected from Pennsylvania, U.S.A., and Cheboygan County, Michigan, U.S.A.; and 3 previously reported taxa recognized as new species: Geneiorhynchus desportesi n. sp. from naiads of Aeshna cyanea (Odonata: Aeshnidae) collected from Montpellier, France, Geneiorhynchus baudoini n. sp. from naiads of Aeschna grandis (Odonata: Aeshnidae) collected from Vincennes and Besse-et-Saint Anastaise, France, and Geneiorhynchus shteini n. sp. from naiads of Aeshna cyanea and Aeshna sp. (Odonata: Aeshnidae) collected from Lakes Pert and Svyat, Karelian Republic, Russian Federation and both Hersbruck and Bamberg, Germany.
Comparative Parasitology | 2008
Autumn J. Smith; Tamara J. Cook
Abstract Eugregarines are typically distinguished using characters, such as epimerite morphology, trophozoite morphometrics, timing of reproductive association, gametocyst morphology, and method of dehiscence. In some cases, new gregarine species have been recognized based solely on host associations, whereas other gregarine species have been reported from several host taxa. We used reciprocal cross-species experimental infections and in vitro excystation assays to evaluate the host specificity of 5 species of eugregarines among 6 species of cockroaches: Protomagalhaensia granulosae Peregrine, 1970, and Gregarina cubensis Peregrine, 1970, described from Blaberus discoidalis, (deaths head cockroach); Leidyana migrator Clopton, 1995, described from Gromphadorhina portentosa (Madagascar hissing cockroach); and Protomagalhaensia wolfi (Geus, 1969) Hays and Clopton, 2006, and Leidyana haasi (Gues, 1969) Hays and Clopton, 2006 infecting Nauphoeta cinerea (lobster cockroach). Eugregarines have not been reported from the other species of cockroaches used in this study: Blaberus giganteus (giant deaths head cockroach), Henschoutedenia flexivitta (giant lobster cockroach), and Diploptera punctata (Pacific beetle mimic). Experimental infections were produced in all homologous host–parasite combinations. With the exception of 1 host–gregarine combination, no infection was produced in heterologous reciprocal combinations. Excystation occurred in all instances when oocysts were placed in homologous host gut homogenate but excystation was never observed in heterologous host gut homogenate.
Comparative Parasitology | 2011
Joanna J. Cielocha; Tamara J. Cook; Richard E. Clopton
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 | 2008
Richard E. Clopton; Tamara J. Cook; Jerry L. Cook
Abstract Trichurispora wellgundis n. g., n. sp. (Apicomplexa: Eugregarinida: Hirmocystidae) is described from the adults of the water scavenger beetle Tropisternus collaris (Coleoptera: Hydrophilidae) collected from B A Steinhagen Lake in the Cherokee Unit of the Big Thicket National Preserve, Tyler County, Texas, U.S.A. Trichurispora is distinguished from known genera of Hirmocystidae by a distinct “trichurisiform” oocyst that is hesperidiform in outline, comprising a fusiform oocyst with shallowly ovoid terminal knobs or caps. Oocyst residua are present but confined to a central fusiform residuum vacuole. Adult and larval hydrophilid beetles represent distinctly different opportunities for parasite colonization and diversification. Gregarines have been reported from both adult and larval hydrophilid beetles, but no species and no genus is reported from both adult and larval hosts. In fact, gregarine taxic richness is often more disparate between adult and larval beetles of the same species than between host beetle species. This is the first report of a septate gregarine from an adult hydrophilid beetle in the Nearctic.
Comparative Parasitology | 2010
Richard E. Clopton; Tamara J. Cook; Joanna J. Cielocha
Abstract Two new species of Nubenocephalus (Apicomplexa: Eugregarinida: Actinocephalidae) are described from adult damselflies sampled in Cayo District, Belize, Central America. Nubenocephalus nickoli n. sp. is described from the American Rubyspot damselfly, Hetaerina americana, and the Smoky Rubyspot damselfly, Hetaerina titia (Odonata: Zygoptera: Hetaerinidae), and Nubenocephalus xunantunichensis n. sp. is described from the Comanche Dancer, Argia chelata (Odonata: Zygoptera: Coenagrionidae). New, complete morphological data sets are reported for populations of Nubenocephalus nebraskensis and Nubenocephalus secundus, and a complete, synoptic reevaluation of diagnostic morphological characters used to discriminate species within Nubenocephalus is presented for all known species of the genus in the New World. Nubenocephalus nebraskensis is reported from Argia apicalis for the first time.
Journal of Parasitology | 2007
Autumn J. Smith; Tamara J. Cook; William I. Lutterschmidt
Gregarina cubensis is an apicomplexan parasite that infects the intestinal lumen of the deaths head cockroach (Blaberus discoidalis). This study evaluated the effects of 3 temperatures on the development and viability of G. cubensis. Three groups of B. discoidalis were inoculated with G. cubensis oocysts and maintained at 15, 27, and 40 C. The alimentary canal was removed from 3 cockroaches in each group every 24 hr until mature gametocysts were found in the rectum or feces, and prepared for histological examination. Gregarina cubensis establishment and development were more rapid at 15 C than at 27 C. Development of G. cubensis at 40 C did not progress beyond the intracellular stage.
Comparative Parasitology | 2008
Richard E. Clopton; Tamara J. Cook; Jerry L. Cook
Abstract Gregarina tropica n. sp. (Apicomplexa: Eugregarinorida) is described from the brown-winged earwig, Vostox brunneipennis (Dermaptera: Labiidae) collected from the Turkey Creek Unit, Big Thicket National Preserve, Tyler County, Texas, U.S.A. We review the morphometric data and nomenclatural status of the 8 previously described species of Gregarina infecting earwigs and recognize 7 valid species: Gregarina ovata, Gregarina nalae, Gregarina megaspora, Gregarina ambigua, Gregarina fallax, Gregarina chelidurellae, and Gregarina labidurae. Although apparently valid taxa, the latter 3 species are very poorly described and thus considered species inquirendae pending new collections and redescription. Gregarina forficulae is recognized as a junior synonymy of G. ovata.
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