American bullfrog control: Application of a biocide

Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
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How is the evidence assessed?

Effectiveness

50%
Certainty

20%
Harms

0%

Calculating overall effectiveness category

Background information and definitions

Biocides may offer a tool for localised eradication or population reduction of American bullfrogs, provided potentially negative effects on native species are carefully managed.

Key messages

One replicated, controlled study in the USA found a number of chemicals killed American bullfrogs, including caffeine (10% solution), chloroxylenol (5% solution), and a combined treatment of Permethrin (4.6% solution) and Rotenone (1% solution).

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A replicated, controlled laboratory study from 2008 to 2009 at the University of California, USA (Snow & Witmer 2010) reported that a number of chemicals killed American bullfrog. Caffeine (10% solution), chloroxylenol (5% solution), and a combined treatment of Permethrin (4.6% solution) and Rotenone (1% solution) each achieved 100% mortality. Dosed on their own, Permethrin (4.6% solution) and Rotenone (1% solution) each achieved 40% mortality. In the trial, approximately 4 ml of treatment solution was sprayed on the entire dorsal surface of randomly-selected groups of bullfrogs using a handheld plastic spray bottle. There were five bullfrogs in each group. Water was used as the solvent for all materials. To improve solubility, a small amount of sodium benzoate was added to the caffeine solution, and a small amount of alcohol was added to the chloroxylenol solution.
Study and other actions tested
Referenced paper
Snow N.P. & Witmer G (2010) American bullfrogs as invasive species: a review of the introduction, subsequent problems, management options, and future directions. 24th Vertebrate Pest Conference, University of California, Davis, USA,.

Please cite as:

Aldridge, D., Ockendon, N., Rocha, R., Smith, R.K. & Sutherland, W.J. (2020) Some Aspects of Control of Freshwater Invasive Species. Pages 555-87 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

This Action forms part of the Action Synopsis:

Control of Freshwater Invasive Species

Related Actions

Actions	Effectiveness	Studies	Category
American bullfrog control: Public education Action Link	No evidence found (no assessment)	0	Synopsis Link
American bullfrog control: Fencing Action Link	No evidence found (no assessment)	0	Synopsis Link
American bullfrog control: Direct removal of juveniles Action Link	Likely to be beneficial	2	Synopsis Link