A study of the chrysopids (Neuroptera : Chrysopidae) in two old fields in Quebec.
| Autor: | Manuel, Raymond Lewis |
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| Jazyk: | angličtina |
| Rok vydání: | 1982 |
| Předmět: | |
| Druh dokumentu: | Electronic Thesis or Dissertation |
| Popis: | Faunistic composition and population dynamics of chrysopids were investigated in two old fields in Quebec. Nine species were collected; Chrysopa oculata Say and Chrysopa chi Fitch are dominant and resident. Parasitism due to Chrysopophthorus americanus Mason has little effect on the reproductive potential of C. oculata and C. chi populations. However, embryonic mortality, resulting from autosomal translocations, is a major mortality factor in both species. Their karyotypes are described and developmental studies conducted on them and Chrysopa lineaticornis Fitch are reported. Inheritance of wing and cephalic characters was investigated in C. oculata. A population genetics study revealed seasonal selection against the allelic gene B (black gradates) and superior fitness of its recessive counterpart b (green gradates). A meiotic drive mechanism also favors the b allele, and the allele A determining "facial band" expression. Chrysopa chi exhibits obligatory and facultative prepupal diapause. The field population, however, is primarily univoltine. Voltinism is controlled by two independently segregating autosomal genes; the recessive alleles, in the homozygous state, determine obligatory diapause and, consequently, univoltinism. Diapause termination is reported. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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