Jerry L. Cook

Conservation of biodiversity in an area impacted by the red imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae)

A conservation study was conducted at Camp Swift, Bastrop County, Texasto determine if the red imported fire ant, Solenopsisinvicta, could be selectively managed to protect endemic antdiversity. The study site was deemed to be an area where S.invicta had recently invaded, and was still in the process ofexpanding its population. The study was conducted between 1998 and 2001, andresulted in significantly higher ant diversity in the area where S.invicta was managed by prescription bait treatments. The controlsite, which was not conserved, lost four endemic ant species during the test,while the treatment site had an increase in one species. This provides evidencethat S. invicta populations can be managed, but may notneed to be eliminated, to preserve ant diversity. New county records are givenfor Brachymyrmex depilis, Foreliusmccooki, F. pruinosus, Gnamptogenyshartmani, Monomorium minimum,Pogonomyrmex comanche, and Tetramoriumspinosum.

Grassland Composition Affects Season Shifts in Seed Preference by Pogonomyrmex barbatus (Hymenoptera: Myrmicinae) in the Edwards Plateau, Texas

Abstract The effects of season and community composition as generated by livestock herbivory of differing intensity on seed species preference by Pogonomyrmex barbatus (F. Smith) were studied in a semiarid savanna on the Edward’s Plateau, TX. Seasonal differences in nutrient requirements of the colony could lead to differential preferences for seeds harvested in spring and fall. Field cafeteria studies were conducted to test the hypothesis that late successional species, with their high nutrient content, would be chosen regardless of grazing intensity or season. Commercial seeds of known nutrient content were used to test the hypothesis that high protein levels would be chosen in spring and high carbohydrate levels in the fall. Naturally occurring seeds were differentially harvested and some were preferred regardless of relative availability. Total seed harvest in cafeteria experiments was higher in spring than in fall. Commercial seeds were harvested equally among treatments within a season; thus, nutrient selection was indistinguishable. Preference for native species was significantly different in both seasons but was influenced by a significant interaction with grazing treatments. Bouteloua curtipendula, a late successional mid-grass, was harvested significantly more in the spring than the fall and at higher rates in the heavily grazed treatment, rejecting the hypothesis that they would be chosen regardless of treatment or season. Seed preference for late successional grasses within heavily grazed communities may slow succession after grazing. During disturbance recovery, late successional species may be reduced by forager preference and rates of spring harvest.

Revision of the Genus Nubenocephalus and Description of Nubenocephalus secundus n. sp. (Apicomplexa: Actinocephalidae) Parasitizing Adults of Argia sedula (Odonata: Zygoptera: Coenagrionidae) in the Primitive Texas Big Thicket, U.S.A.

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.

Revision of Geneiorhynchus Schneider, 1875 (Apicomplexa: Eugregarinida: Actinocephalidae: Acanthosporinae) with Recognition of Four New Species of Geneiorhynchus and Description of Geneiorhynchus manifestus n. sp. Parasitizing Naiads of the Green Darner, Anax junius (Odonata: Aeshnidae) in the Texas Big Thicket

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.

Trichurispora wellgundis n. g., n. sp. (Apicomplexa: Eugregarinida: Hirmocystidae) Parasitizing Adult Water Scavenger Beetles, Tropisternus collaris (Coleoptera: Hydrophilidae) in the Texas Big Thicket

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.

Review of the Biology of Parasitic Insects in the Order Strepsiptera

ABSTRACT: The order Strepsiptera comprises an enigmatic group of insects with a complex life cycle that includes a long, obligate endoparasitic phase. Due to the unusual characteristics of the strepsipteran life cycle, its natural history and classification have long been a source of confusion. Unique life-history strategies and extreme morphological modifications within this group have promoted many philosophical discussions between systematists and entomologists. Although this situation had left the relationship of strepsipterans with other insect groups continually in question for many years, the current general consensus is that Strepsiptera is a sister group to Coleoptera. Members of the Strepsiptera exhibit pronounced sexual dimorphism, 2 distinct larval forms, a pupal stage, host manipulation, and morphological characteristics that include many unusual differences from other insects.

NEW HOST ASSOCIATION, DISTRIBUTION, AND MORPHOLOGICAL VARIATION IN CAENOCHOLAX FENYESI (STREPSIPTERA: MYRMECOLACIDAE)

Abstract Records of the distribution and host associations of Caenocholax fenyesi continue to increase. Crematogaster laeviuscula is reported for the first time as a host of male C. fenyesi, increasing the number of known male hosts to seven species in three subfamilies of Formicidae. Additionally, the distribution of C. fenyesi continues to become better known, with a first record from Colombia and additional records from Panama and Mexico added herein. Noted variation in aedeagus morphology from this study and previous evidence of genetic differences suggests that C. fenyesi, which is currently recognized as a monotypic species, is most likely a species complex.

Harvester Ant Nests Improve Recovery Performance of Drought Impacted Vegetation in Grazing Regimes of Semiarid Savanna, Texas

ABSTRACT Vegetation composition is often dictated by grazing intensity in semiarid savannas; recovery following drought may depend on pre drought species composition. Nests of the red harvester ant, Pogonomyrmex barbatus, affect the dynamics, composition and recovery of post drought communities due to their larger size, greater seed production and higher perennial grass richness. We hypothesized that vegetation at ant nests would survive drought and recover faster than vegetation in the surrounding grasslands, but that individual and population recovery would depend on plant species composition, which, in turn, would be influenced by grazing intensity. We assessed nest influence on density, cover, number of inflorescences and dynamics of grass and forb species. Disk margins (area encircling the ant nest) were compared with grassland locations in unreplicated heavy, light and ungrazed treatments before, immediately after and one year after a severe drought. Significantly greater aerial and basal cover of grasses was found on disk margins compared to grasslands in each treatment. Grass cover and number of inflorescences increased faster on disk margins compared to grasslands. Fastest grass growth was seen on margins in the ungrazed treatment. There was greater diversity in ungrazed treatments of grazing intolerant mid-grasses compared to the grazed treatments, suggesting that mid-grasses may persist belowground, leading to faster productivity in the ungrazed treatment. Grass densities were generally higher and increased faster in grasslands resulting in smaller grasses compared to the large, more robust grasses on disk margins. Forbs showed significantly lower abundance and cover on margins compared to grasslands. These observations suggest that red harvester ant nests may serve as drought refugia for grass survival and a seed source for recovering grass populations after drought in semiarid savannas.

Rapid Spread of Balclutha rubrostriata (Hemiptera: Cicadellidae) in Texas and Southwestern Louisiana, USA with Notes on its Associated Host Plants

ABSTRACT The red streaked leafhopper, Balclutha rubrostriata (Melichar) (Hemiptera: Cicadellidae), is an invasive insect from southeastern Asia that is known to be a vector of the phytoplasma that causes Sugarcane White Leaf Disease (SCWL). Sugarcane is a vital crop for the United States and is being considered as a biofuel source. The purpose of this survey was to determine whether B. rubrostriata has established populations in Texas and Louisiana, USA; and, if established, to estimate its range expansion. The gulf coast region of Texas, east Texas, and 2 southwestern parishes of Louisiana were surveyed for the red streaked leafhopper. Samples of the leafhopper were collected in all Gulf Coast regions and the majority of east Texas counties. However, it was only collected in one Louisiana parish. The leafhopper appears to be closely associated with an invasive grass, King Ranch Bluestem, Bothriochloa ischaemum (L.), throughout much of its present range in the United States, and it is now common along much of the Texas Gulf Coast and is moving into Louisiana.

Gregarina tropica n. sp. (Apicomplexa: Eugregarinorida: Gregarinicae: Gregarinidae) Parasitizing the Brown-Winged Earwig, Vostox brunneipennis (Dermaptera: Labiidae), in the Texas Big Thicket

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.