• Login
    View Item 
    •   Home
    • Massey Documents by Type
    • Theses and Dissertations
    • View Item
    •   Home
    • Massey Documents by Type
    • Theses and Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Factors influencing host finding behaviour of hessian fly : a thesis presented in partial fulfilment of the requirements for the degree of Doctorate of Philosophy in Plant Health at Massey University, Palmerston North, New Zealand

    Icon
    View/Open Full Text
    02_whole.pdf (4.912Mb)
    01_front.pdf (944.4Kb)
    Export to EndNote
    Abstract
    The influence of environmental and plant variables on the behaviour of female Hessian flies (Mayetiola destructor Say) during opposition were investigated. Female behaviour was observed with respect to different spatial and plant variables in a large arena in a greenhouse. The distance between patches of wheat (Triticum aestivum L.) plants and the number of plants in patches did not influence the allocation of time to flight, examining and oviposition behaviours on plants, or time spent in a patch and the numbers of eggs laid there. Females did alter their behaviour by partitioning time differently within large versus small patches. When the ratio of wheat to non-host plants, oat (Avena sativa L.) was altered, females spent more time and laid more eggs on wheat, despite non-selective alighting. Influences of wind and plant stimuli on flight and egglaying decisions were studied in a wind tunnel. As wind speed increased, the time spent on wheat and oat plants before leaving increased and the number of oviposition bouts on the plant increased proportionately. Observed flights showed females losing control of flight direction and less able to reach plants in winds over 0.9 m/s. Under such conditions, females moved in a down-wind direction in the wind tunnel. The consequences of egg clutch size for a female offspring were studied by manipulating egg clutches on individual plants. Mortality increased and offspring size decreased with increasing clutch size. As adult body size is proportional to fecundity in female Hessian fly, females maximise reproductive fitness by laying small clutches. However, if adult females do not survive to lay all their eggs, reproductive fitness may be increased by laying larger clutches. These different oviposition strategies are visible in female behaviour under differing environmental conditions. A study of the movement of female Hessian flies in small field plots extended and verified results from lab-based studies. Females moved faster through an area of plants than was predicted by random diffusion models. The percentage of females recaptured from circular arrays of wheat or oat plants using a D-Vac insect sampler decreased as the time since release into a central patch increased. Recapture rates were lower in non-host compared to host plant arrays. Results suggest that female Hessian flies can readily move considerable distances in the field, and if eclosing in a non-host field habitat, will move extensively in search of host plants. The degree to which spring wheat crops in New Zealand are presently under threat from Hessian fly was ascertained through a field survey. Some areas of mid and south Canterbury showed high pupal numbers. All cultivars presently sown in New Zealand appeared to be susceptible to feeding by Hessian fly larvae.
    Date
    1995
    Author
    Withers, Toni May
    Withers, Toni May
    Rights
    The Author
    Publisher
    Massey University
    URI
    http://hdl.handle.net/10179/2973
    Collections
    • Theses and Dissertations
    Metadata
    Show full item record

    Copyright © Massey University
    | Contact Us | Feedback | Copyright Take Down Request | Massey University Privacy Statement
    DSpace software copyright © Duraspace
    v5.7-2020.1-beta1
     

     

    Tweets by @Massey_Research
    Information PagesContent PolicyDepositing content to MROCopyright and Access InformationDeposit LicenseDeposit License SummaryTheses FAQFile FormatsDoctoral Thesis Deposit

    Browse

    All of MROCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    Statistics

    View Usage Statistics

    Copyright © Massey University
    | Contact Us | Feedback | Copyright Take Down Request | Massey University Privacy Statement
    DSpace software copyright © Duraspace
    v5.7-2020.1-beta1