Award details

Movement and population dynamics of insect pests and beneficial organisms in farmland

Reference	BBS/E/C/00041193
Principal Investigator / Supervisor	Professor Wilfred Powell
Co-Investigators / Co-Supervisors
Institution	Rothamsted Research
Department	Rothamsted Research Department
Funding type	Research
Value (£)	254,015
Status	Completed
Type	Institute Project
Start date	01/04/1997
End date	31/03/1999
Duration	24 months

Abstract

Recent ecological theory has highlighted spatial heterogeneity, within habitats and in the landscape, as an important factor influencing the local population dynamics of both plants and animals. In particular, habitat and resource patchiness is believed to be a major factor promoting stability in predator/prey and parasitoid/host relationships. 2 The effects of habitat fragmentation are being studied in an experimental arena, consisting of a series of sown semi-natural habitat patches within an arable field. This allows a number of parameters such as patch size, degree of fragmentation and distances between habitat patches to be controlled and manipulated. Long-term data is being collected to investigate the effects of habitat fragmentation on a model tritrophic system invoving a plant, two herbivorous weevils and their associated parasitic wasps. The movements and community structure of carabid beetles within the patch system are also being studied. 3 This work is complemented by studies of the plant communities in the sown grass/flower patches. The patch experiment is also being used to study the foraging behaviour of bumble bees and hoverflies. Within the natural farmland ecosystem, the local structure of aphid parasitoid populations is being investigated in relation to habitat and host spatial distribution. Molecular techniques are being used to assess the level of gene flow between local populations of parasitic wasps in different habitat patches and on different host species. Wind tunnel bioassays are being used to investigate the host location behaviour of aphid parasitoids, particularly their responses to semiochemical cues within the tritrophic plant- aphid-parasitoid system.Particular attention is being paid to plant-derived semiochemicals which act as synomones and aphid sex pheromones which function as kairomones for foraging parasitoids. Knowledge gained from this project is being used to design sustainable pest control strategies involving appropriate habitat and landscape management, in conjunction with beneficial insect manipulation. 1.To use statistical techniques to analyse spatial population data relating to the model plant-herbivore-parasitoid system sampled over the past four years. 2.To write up completed analyses of predatory beetle population and community data collected over the past five years from the farmland ecology patch experiment. 3.To initiate new studies on the influence of habitat fragmentation on communities of aphids and their natural enemies within fragmented habitat patches. 4.To investigate population structure of the aphid parasitoid Praon volucre in relation to habitat and host spatial distributions. 5.To determine the role of associative learning in the host finding behaviour of aphid parasitoids. 6.To set up field trials to measure the spread of aphid-pathogenic fungi between aphid colonies in crops and other habitats and to assess the potential of ladybirds as pathogen vectors. 7.To determine, under field conditions, the distance over which the conidia of the entomopathogenic fungus Erynia neoaphidis can travel through the air and remain viable from sources within hedgerows and crop fields. 1. To continue long-term population studies on the tritrophic plant-weevil- parasitoid system within the habitat fragmentation (patch) experiments. 2.To investigate further bee foraging patterns at several spatial scales, relating these to pollen flow, particularly with respect to wild plant species growing in a fragmented environment. 3. To complete studies of the host preference behaviour of the generalist aphid parasitoid Praon volucre in relation to population structure within the farmland ecosystem. 6. To determine the relative importance of genetics, conditioning and learning in the host location and host recognition behaviour of aphid parasitoids. 4.To compare the use of different semiochemical cues by specialist and generalist parasitoid species during host location.

Summary

unavailable

Committee	Closed Committee - Agri-food (AF)
Research Topics	X – not assigned to a current Research Topic
Research Priority	X – Research Priority information not available
Research Initiative	X - not in an Initiative
Funding Scheme	X – not Funded via a specific Funding Scheme

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