Browsing by Author "Carle, Frank Louis"

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    A contribution to the knowledge of the odonata
    Carle, Frank Louis (Virginia Tech, 1982-06-16)
    Theories concerning the origin of insect wings and flight are reviewed and a new scenario for their origin proposed. It is suggested that environmental conditions of the small stream were responsible for the evolution of insect flight, and that thermoregulation as well as respiration was important in the preadaptation of wings. The possibility that the five paired convex-concave vein systems each represented a dorsal-ventral blood channel is suggested. Odonate wing vein homology and nomenclatural systems, and phylogeny are reviewed. The process of vein loss is evaluated in the Palaeoptera and a new system of odonate wing vein homologies proposed. The odonate wing mechanism is analyzed and the heretofore overlooked discal nodus characterized. Reevaluation of the comparative morphology of fossil and recent Odonata indicates that Protozygoptera and Protanisoptera represent evolutionary side branches, that the Anisozygoptera is polyphyletic, and that Isophlebiidae and Calopterygoidea are the most generalized Odonata known. Previous scenarios explaining evolution of the unique odonate copulatory process are reviewed. Considering the copulatory behavior of the Calopterygoidea generalized supports evolutionary trends toward male domination and in-flight completion of the process. Assuming direct sperm transfer the original odonate mode requires that originally oviposition be in tandem and that sperm transfer to and from male anterior abdominal sterna be accidental. In contrast, assuming an original indirect transfer of sperm leads to a copulatory sequence similar to that of the Odonata. The proposed scenario differs from others in that extraordinary postures are not envisioned, the process is completed at rest, and the odonate tandem hold is developed prior to copulation. Anisopteran morphology and phylogeny are reviewed and reliable dentification keys developed for North American families and genera, and for 180 anisopteran species collected in Virginia and vicinity. Each species is described and photographed, including seven new species. The biogeography of Virginia Anisoptera is best explained by overlapping biotic regions, the fauna being a mixture of eastern North American, boreal, and tropical elements. New efficient methods for collecting, preserving, and rearing Odonata are described.
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    An evaluation of the removal method for estimating benthic populations and diversity
    Carle, Frank Louis (Virginia Tech, 1976-05-15)
    A Circular Depletion Sampler (the CDS) was constructed in order to collect removal data for estimating benthic sample populations and species catchability. The removal sampling method was compared to Modified Hess, Surber, and Kicknet sampling methods, and gave consistently higher and less variable estimates than other methods. Taxa showing the lowest catch abilities included the case-building Trichoptera, the Mollusca, and the Annelida. The highest catch abilities were shown by the smaller Chironomidae and the nonburrowing Ephemeroptera. Taxa with high catchability generally showed high emigrability for Surber and Kicknet methods, particularly the aquatic Insecta. The determination of species richness and evenness diversity was significantly biased by low catchabilities or emigration or both with Modified Hess, Surber, and Kicknet sampling methods. Removal samples have a higher probability of representing rare species, and as expected, pooled removal collections accumulated species at a higher rate than the pooled collections of other methods. The dominance diversity of pooled CDS collections became stable more rapidly than those of other methods, and gave higher resolution between benthic communities of different structure. DPLETE, a computer program for making removal population estimates by the method of Carle and Strub (1976) and making dominance diversity estimates based on information theory is presented, and is suitable for use in any study where removal data has been collected.