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Investigating indirect effects of insecticides upon Collembola - PS2324

In contrast to the situation for predatory arthropods, relatively little information is available on the impacts of widely-used insecticides upon Collembola. Effects of cypermethrin, pirimicarb and chlorpyrifos were therefore investigated during summer 1994 in a replicated field study in four winter wheat fields. Statistically significant increases in Collembola abundance were caused by applications of cypermethrin and pirimicarb. Evidence from other sources suggests that such indirect effects on Collembola might occur relatively frequently. The increased catches of Collembola following insecticide applications are of relevance to risk assessment because they reflect effects upon multiple species and ecological interactions. Such indirect effects are unlikely to be detected under the current pesticide risk assessment scheme (as guided by Directive 91/414/EEC).

The original work has been published, but limited resources restricted the initial analysis to 25% of the available suction samples that were collected. An opportunity exists to extend the initial data set by analysing the remaining 75% of samples, which have been preserved. This project would improve understanding of indirect effects of insecticides upon Collembola in a cost-effective way by making use of the available samples. The information arising from this work would assist pesticide risk assessment by clarifying the importance of indirect effects of insecticides upon Collembola. In particular, the persistence of indirect effects needs to be established, as this may have a bearing on the interpretation of the acceptability of environmental impacts. The work would also contribute effects data for the three insecticides to improve the database in the DEFRA WEBFRAM-5 project (PS2305).
Objective 1: Identify Collembola and their predators in existing suction samples to determine the persistence and taxonomic spectrum of insecticide effects. This would extend an existing data set from 10 days after treatment to 45 days after treatment (adding six sampling dates). The aim is to determine the persistence and taxonomic spectrum of insecticide-induced increases in Collembola caused by cypermethrin and pirimicarb; data would also be available for chlorpyrifos, to enable the comparison of direct and indirect effects.

Objective 2: Analyse, interpret and report the findings. The output would comprise: (1) analysis of the persistence of indirect effects; (2) analysis of the taxonomic spectrum of indirect effects; (3) multivariate analysis of the Collembola community response that summarises and tests statistically both indirect and direct effects; (4) effects data sets for cypermethrin, pirimicarb and chlorpyrifos for input to the WEBFRAM-5 project.

Project Documents
• Final Report : Investigating indirect effects of insecticides upon Collembola   (693k)
Time-Scale and Cost
From: 2005

To: 2006

Cost: £25,679
Contractor / Funded Organisations
University - Southampton
Environmental Impact              
Insecticide use              
Pest and Weed Control              
Plants and Animals              
Fields of Study
Pesticide Safety