Causal Analysis of a Migration of the Snout Butterfly, Libytheana bachmanii Iarvata (Strecker) (Libytheidae)

Observation of a massive migration of the snout butterfly, Libytheana bachmanii larvata (Strecker), in central Texas in 1971 is described. An association of peak migration periods and periodic precipitation episodes is believed to be causal in nature.Waller Creek Working Grou

Paleoecological Implications of a Holocene Fossil Assemblage: Lower Rio Grande, Cameron County, Texas

Contents: Abstract -- Acknowledgments -- Introductions -- Fossil Site -- Fossil Assemblage -- Aquatic Mollusks -- Miscellaneous Biota -- Plant Remains -- Age of Fossil Site -- Paleoenviromental Reconstruction -- Origin of Fossil Assemblage -- Paleogeological and Paleoclimatological Implications -- Concluding Remark -- ReferencesA Late Holocene fossil site from extreme southern Texas consists of invertebrate remains dominated by terrestrial, freshwater and brackish water mollusks. Sparse plant remains were recovered. Analysis of the origin of this heterogeneous fossil biota indicates that a brackish marsh was periodically inundated by freshwater runoff. The presence of a marsh clam not known living in the area today is significant; the fossil site is reconstructed to have been a brackish marsh habitat at elevation of 3.6 meters above mean sea level. A brackish marsh at this elevation may indicate high sea levels, although existence of nontidal brackish marshes are known from the lower Texas coast. Changes in river flow and seasonal distribution of local precipitation, and/or regional runoff, are postulated to explain the existence of a saline marsh in an area where this biotype is extremely rare today.Texas Memorial Museu

Paleoclimatic Reconstruction Based on Molluscan (Gastropoda, Pelecypoda) Environmental Indicators-Late Quaternary of Northwestern Texas

Paleoecologic interpretation of fossil molluscan faunas provides a basis for indirect reconstruction of paleoclimates. Terrestrial and aquatic mollusks are abundant in late Quaternary sedimentary deposits of the western Rolling Plains of Texas. These taxa compose a succession of distinct faunal assemblages. Most mollusks represented in late Pleistocene to middle Holocene assemblages of the region are absent from the modern fauna. However, none of the extirpated species are extinct; their distribution has merely been reduced such that at present, these taxa are found northeast or in montane areas west of the Southern High Plains and Rolling Plains. Because they are living species, their environmental requirements, habitat, and climate are relatively well known. Environments that sustain these mollusks today are presumed to have existed in northwestern Texas in the past. Ecological conditions throughout the Pleistocene and Holocene Epochs can be inferred by tracing the range of environmentally sensitive taxa through radiocarbon-dated stratigraphic sequences. Allowance is made for local variations owing to facies changes and temporary modifications of habitat. Conditions in this region during the late Pleistocene favored diverse molluscan faunas. By comparison, the living fauna is depauperate and virtually restricted to species with broad environmental tolerances; climatic and ecological change was gradual, affecting different species at different times. Regional extirpation of a number of species with comparable ecologic requirements indicates a profound change in environment probably related to climate. Data from three well-constrained stratigraphic sections permit refinement of existing paleoclimatic reconstructions. Climatic variations during the Holocene have taken two related but somewhat independent paths. A summer warming trend that began in the latest Pleistocene greatly increased temperatures by about 8,000 years before present. A similar trend toward desiccation was accelerated between 8,000 and 6,000 years before present until essentially modern conditions were attained 3,000 years before present. Other, comparatively minor fluctuations of the regional paleoclimate are evident as well.Bureau of Economic Geolog

Aberrant Reproductive Behavior Patterns Of Dragonflies In Human Impacted Habitats Odonata Libellulidae

Volume: 87Start Page: 181End Page: 18

On the origin of snout butterflies (Libytheana bachmanii larvata, Libytheidae) in a 1978 migration in southern Texas

Volume: 38Start Page: 319End Page: 32

HAWK MOTHS SPHINGIDAE IN THE WHITLEY COLLECTION FROM WALKER COUNTY TEXAS

Volume: 45Start Page: 231End Page: 23

CAUSAL ANALYSIS OF A MIGRATION OF THE SNOUT BUTTERFLY LIBYTHEANA-BACHMANII-LARVATA LIBYTHEIDAE

Volume: 37Start Page: 121End Page: 12

LEAF SELECTION FOR OVIPOSITION SITES BY A TROPICAL SKIPPER BUTTERFLY PHOCIDES-LILEA-SANGUINEA

Volume: 35Start Page: 240End Page: 24