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Providing evidence to improve practice

Action: Procambarus crayfish control: Add chemicals to the water Control of Freshwater Invasive Species

Key messages

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  • One replicated, controlled study in Italy found that red swamp crayfish could be killed using the natural pyrethrum Pyblast at a concentration of 0.05 mg/l, but that application to drained crayfish burrows was not effective.


Supporting evidence from individual studies


One replicated, controlled study in 2009 in Italy (Cecchinelli et al. 2012) found that natural pyrethrum (Pyblast) concentrations of 0.05mg/l and higher resulted in 100% mortality of red swamp crayfish Procambarus clarkii under laboratory conditions, 95% mortality when 0.05mg/l Pyblast was applied to a drainage channel, but no mortality following application of 0.05 mg/l Pyblast into active crayfish burrows. For the drainage channel study, two 50m-long upstream control transects were compared with two downstream transects treated with 0.05 mg/l Pyblast, and mortality of crayfish in each transect was monitored recorded every 24 h for 96 h.  For the burrow study, a 0.3 l solution of 0.05 mg/l Pyblast was injected up to 2 m inside active crayfish burrows after the channel had been drained. Crayfish population changes were assessed by comparing capture rates in four replicated, baited traps before and after the treatment.


Referenced papers

Please cite as:

Aldridge, D., Ockendon, N., Rocha, R., Smith, R.K. & Sutherland, W.J. (2019) Some aspects of control of freshwater invasive species. Pages 569-602 in: W.J. Sutherland, L.V. Dicks, N. Ockendon, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2019. Open Book Publishers, Cambridge, UK.