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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A biological-taxonomic study of the Neodiprion virginianus complex in Wisconsin

Becker, George Charles, January 1965 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1965. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
2

The biology and ecology of the red-pine sawfly in Wisconsin

Kapler, Joseph Edward, January 1958 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1958. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 73-74).
3

Preliminary investigation of the influence of photoperiod and temperature on the development of multivoltine populations of Neodiprion rugifrons Middleton

King, Lonn Louis, January 1965 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 43-44.
4

Phenotypic variation in host quality of pines for the European pine sawfly (Neodiprion sertifer)

Chorbadjian, Rodrigo A., January 2009 (has links)
Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 134-151).
5

Syntheses of Allelochemicals for Insect Control

Smitt, Olof January 2002 (has links)
This thesis describes the synthetic preparation of somecompounds, which can serve as chemical signals for use in thedevelopment of control methods for pest insects. The compoundssynthesised are of the isoprenoid type and of two kinds:carvone derivatives and germacranes. The derivatives of carvoneare based on modifications of this compound, by reactions ofeither its endocyclic or its exocyclic double bond. One type ofmodifications was accomplished by chemoselective additions ofthiophenol. The latter ones imply additions to the exocyclicdouble bond and seem to constitute general, previously rarelystudied reactions. In other modifications of its exocyclic side chain, carvoneafforded some sesqui- and diterpeniod natural products. Thefollowing compounds were synthesised in an enantioselectiveway: (-)-epi-delobanone, (-)-delobanone,(-)-7-hydroxy-3,10-prenylbisaboladien- 2-one (an insecticidalconstituent of Croton linearis) as well as its diastereomer andsome other compounds with similar structures. All of thesecompounds weretested for their antifeedant/feeding deterrentcapability against gnawing of the pine weevil, Hylobiusabietis. The germacranes prepared by means of enantioselective totalsyntheses are: (–)- 1(10),5-germacradien-4-ol and(–)-germacrene D. The former is a constituent of thedefence secretion (an allomone) from the larvae of the pinesawfly, and the needles of Scots pine. (–)-Germacrene D isa ubiquitous compound in nature. For example, it occurs in thepeels of apples and acts as one component of a lure (akairomone) to the apples, which attracts the codling moth,Cydia pomonella. The main problem in the total syntheses of the germacraneswas the formation of the unsaturated monocyclic 10-memberedring. This was achieved by intramolecular alkylation with asuitably functionalised/protected cyanohydrin derivative,which, after further elaboration, afforded a monocyclic10-membered enone, that was used in the syntheses of the twogermacranes mentioned above. In the initial steps in thesynthetic sequence the stereochemistry was established byalkylation of an amide enolate attached to a chiral auxiliary.This approach could most likely also readily furnish the(+)-enantiomers of these germacrenes (of the germacraneterpenoid class) using the opposite enantiomer of the chiralauxiliary in the initial steps. <b>Keywords</b>: isoprenoids, natural product synthesis,allelochemicals, kairomones, allomones, bisabolane terpenoids,Hylobius abietis, germacrane terpenoids, Neodiprion sertifer,stereoselective synthesis.
6

Syntheses of Allelochemicals for Insect Control

Smitt, Olof January 2002 (has links)
<p>This thesis describes the synthetic preparation of somecompounds, which can serve as chemical signals for use in thedevelopment of control methods for pest insects. The compoundssynthesised are of the isoprenoid type and of two kinds:carvone derivatives and germacranes. The derivatives of carvoneare based on modifications of this compound, by reactions ofeither its endocyclic or its exocyclic double bond. One type ofmodifications was accomplished by chemoselective additions ofthiophenol. The latter ones imply additions to the exocyclicdouble bond and seem to constitute general, previously rarelystudied reactions.</p><p>In other modifications of its exocyclic side chain, carvoneafforded some sesqui- and diterpeniod natural products. Thefollowing compounds were synthesised in an enantioselectiveway: (-)-epi-delobanone, (-)-delobanone,(-)-7-hydroxy-3,10-prenylbisaboladien- 2-one (an insecticidalconstituent of Croton linearis) as well as its diastereomer andsome other compounds with similar structures. All of thesecompounds weretested for their antifeedant/feeding deterrentcapability against gnawing of the pine weevil, Hylobiusabietis.</p><p>The germacranes prepared by means of enantioselective totalsyntheses are: (–)- 1(10),5-germacradien-4-ol and(–)-germacrene D. The former is a constituent of thedefence secretion (an allomone) from the larvae of the pinesawfly, and the needles of Scots pine. (–)-Germacrene D isa ubiquitous compound in nature. For example, it occurs in thepeels of apples and acts as one component of a lure (akairomone) to the apples, which attracts the codling moth,Cydia pomonella.</p><p>The main problem in the total syntheses of the germacraneswas the formation of the unsaturated monocyclic 10-memberedring. This was achieved by intramolecular alkylation with asuitably functionalised/protected cyanohydrin derivative,which, after further elaboration, afforded a monocyclic10-membered enone, that was used in the syntheses of the twogermacranes mentioned above. In the initial steps in thesynthetic sequence the stereochemistry was established byalkylation of an amide enolate attached to a chiral auxiliary.This approach could most likely also readily furnish the(+)-enantiomers of these germacrenes (of the germacraneterpenoid class) using the opposite enantiomer of the chiralauxiliary in the initial steps.</p><p><b>Keywords</b>: isoprenoids, natural product synthesis,allelochemicals, kairomones, allomones, bisabolane terpenoids,Hylobius abietis, germacrane terpenoids, Neodiprion sertifer,stereoselective synthesis.</p>
7

EXAMINING THE ROLE OF HOST USE ON DIVERGENCE IN THE REDHEADED PINE SAWFLY, <em>NEODIPRION LECONTEI</em>, ACROSS MULTIPLE SPATIAL SCALES

Bagley, Robin Kimberly 01 January 2017 (has links)
Phytophagous insects make up over one quarter of described species on Earth, and this incredible diversity seems directly linked to feeding on plants. Comparative studies of sister groups have shown shifts to herbivory are consistently associated with increased species diversity in insects, but the reasons for this diversification remain unclear. While other explanations, such as decreased extinction rates or influences on population structure, exist, one prominent hypothesis suggests shifts and subsequent adaptation to novel host plants can lead to the evolution of reproductive barriers. Given their extreme specialization on host plants in the genus Pinus and intimate, life-long association with their host plants, divergent host use has been suspected to drive speciation in the conifer sawfly genus Neodiprion. Previous work showed host shifts coincide with speciation events in the genus; but could not determine if these host shifts initiated speciation or if they occurred after other reproductive barriers arose. Determining the contribution and timing of host shifts relative to speciation will require examination of populations at the earliest stages of divergence, before post-speciation changes amass. If host shifts frequently drive speciation in the genus, there will likely be evidence of host-driven divergence within species occurring on a wide range of host plants. The goal of this dissertation is to examine populations of the red-headed pine sawfly, Neodiprion lecontei, an abundant, well-studied pest species that occurs on multiple hosts throughout its range, for evidence of host-driven divergence. Using a combination of reduced representation genomic sequencing, population genomics, and ecological assays, I specifically look for evidence of 1) genetic differentiation between populations utilizing different host plants, 2) ecological divergence in female oviposition preference, larval performance, and ovipositor morphology between populations on different hosts, and 3) ecologically-driven reproductive isolation between genetically and ecologically divergent populations. Each chapter of this dissertation examines the role of host use in driving ecological, genetic, and/or reproductive divergence within N. lecontei at a different spatial scale. First, I surveyed range-wide patterns of diversity. I identified three genetic clusters, dated the divergence of these clusters to the late Pleistocene, and found evidence that both dispersal limitation (geography) and host use contribute to genetic differentiation within N. lecontei. Next, I looked within one of these genetic clusters for additional evidence of the role of host in driving divergence. Sawflies in this cluster primarily utilize two hosts which differ significantly in needle architecture. Although I found no evidence of neutral genetic differentiation between hosts exists, I did detect spatial and temporal differences in host use, and host-specific differences in ovipositor morphology, a performance-related trait. Finally, I examine a single site where N. lecontei utilizes three structurally divergent species of pine. Although there was little genetic structure, no sexual isolation, and no distinct host preferences, the host types were partially temporally isolated and varied in ovipositor morphology and larval performance across on the three hosts. Overall, although divergent host use consistently resulted in divergent ovipositor morphology, a reduction in gene flow via temporal or geographic isolation may be required before additional forms of ecological and genetic differentiation can develop. Together these results suggest host shifts alone may not be enough to drive population divergence and speciation in Neodiprion.

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