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THE EVOLUTIONARY ECOLOGY OF A SPECIES-RICH SYMPATRIC ARRAY OF CATOCALA MOTHS (FOODPLANTS, SPECIFICITY)

Posted on:1985-05-02Degree:Ph.DType:Dissertation
University:Yale UniversityCandidate:GALL, LAWRENCE FREDERICKFull Text:PDF
GTID:1478390017461642Subject:Ecology
Abstract/Summary:
Species in the large Holarctic noctuid moth genus Catocala are striking exceptions to the general rule in macrolepidoptera of foodplant divergence among close relatives. The 25 feeders on plants in the family Juglandaceae have narrow foodplant use, synchronous phenologies, similar morphologies, and show extensive microsympatry throughout their restricted eastern Nearctic range.;Only 1 of the 11 Juglandaceae-feeders proves to have a unique foodplant, a pecan; 2 others use walnut; the remaining 8 are tied to the biology of Shagbark Hickory (Carya ovata), an array of 5 very closely related species among them having essentially identical foodplant ecologies in all developmental stages. The foodplant divergences that do exist parallel closely the taxonomic divisions within Juglandaceae. The extent to which the 8 species feeding on hickory compete with each other for food and other resources is discussed; episodic larval competition with the Gypsy Moth, an introduced defoliator, is shown to be intense. Fine-grained distributions of larvae on individual trees are also presented, as are some aspects of Catocala predator-parasitoid relationships.;Capacities for major foodplant shifting among the Juglandaceae feeders are limited at present. This also appears to be the case with the oak and Salicaceae feeders, who have comparably overlapping larval biologies. Foodplant conservatism over evolutionary time characterizes Catocala, the pattern being clearest at the intrageneric levels of both moths and foodplants. Combining systematic and ecological results for Catocala reveals the general power of such an integrated approach for studying historical patterns in host range evolution.;This dissertation covers the ecological and evolutionary reasons for such species packing, focusing on the foodplant-linked biologies and patterns of resource use shown by 11 Juglandaceae-feeding, 7 Salicaceae-feeding, and 5 oak-feeding Connecticut Catocala. The experimental approaches are: assessment of larval foodplant and adult oviposition preferences; controlled rearings under field conditions; field sampling of trees for larvae and adults. Numerical taxonomic analyses of affinities within the genus are presented to frame the questions about evolution of foodplant ecology.
Keywords/Search Tags:Foodplant, Catocala, Species, Evolutionary
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