Essays about: "insects response"

Showing result 21 - 25 of 25 essays containing the words insects response.

  1. 21. Plume interaction and odour source spacing ofpheromone and non-host volatiles : : Behaviouraleffects on bark beetles and moths

    University essay from SLU/Dept. of Plant Protection Biology

    Author : Muhammad Binyameen; [2009]
    Keywords : Odour; plume structure; plume interactions; Spodoptera littoralis; S. litura; Ips typographus; Lepidoptera; Noctuidae; Coleoptera; Scolytidae; PID; orientation; sex pheromone; NHV ;

    Abstract : Insects have a remarkable ability to sense whether odours are released from one point source or from two closely separated ones. Therefore it is of interest to study the interactions of pheromone component odour plumes to affect the insect behaviour when the release points ofdifferent components are physically separated. READ MORE

  3. 22. Metapopulation persistence of insects living in hollow oaks: effects of adding oaks in  the surrounding landscape

    University essay from Institutionen för fysik, kemi och biologi

    Author : David Gilljam; [2009]
    Keywords : Metapopulation; Matrix; Fragmentation; Hollow oaks; Saproxylic; Conservation; Restoration;

    Abstract : The oak district of Östergötland is one of the largest oak forests left in Europe and it harbours many threatened species dependent on old hollow trees. In this study, the saproxylic beetle Osmoderma eremita living in hollow oaks was used as a model species and parameterised for a metapopulation model (the incidence function model) at the level of individual trees. READ MORE

  4. 23. Correlation between photoperiod and development rate in the damselfly Lestes sponsa (Hansemann) : A compensating mechanism across latitudes?

    University essay from Institutionen för ekologi, miljö och geovetenskap

    Author : Szymon Sniegula; [2009]
    Keywords : development insects aquatic ecology;

    Abstract : Although there is much theoretical and empirical data about the life history responses of time constrained organisms, little is known about the latitude compensating mechanism that enables northern populations’ developmental rates to compensate for latitude. To investigate the importance of photoperiod on development and growth, I collected adults and raised the offspring of the obligatory univoltine damselfly Lestes sponsa from two populations at different latitudes (53º N and 63º N). READ MORE

  5. 24. Indirect effects of mammalian herbivores on invertebrates in a river gradient of the Kruger National Park, South Africa

    University essay from SLU/Dept. of Wildlife, Fish and Environmental Studies

    Author : David Bell; [2008]
    Keywords : large herbivores; aavanna system; Kruger national park; insects response;

    Abstract : Savanna biomes have been heavily affected by fire suppression, and changed grazing and browsing regimes, caused by human interventions. As a result many biotic interactions, and ecosystem functions, have been altered. READ MORE

  6. 25. Induced defense in tomato damaged by Spodoptera littoralis larvae

    University essay from SLU/Dept. of Plant Protection Biology

    Author : Anna Eriksson; [2007]
    Keywords : tomato; induced defense; Spodoptera littoralis;

    Abstract : Plants defend themselves against feeding insects via both a constitutive; always existing defense, and/or via an induced defense that is activated in response to the feeding damage. The aim of this study was to investigate the induced defense in tomato after damage by insect larvae. READ MORE