Action Synopsis: Bee Conservation About Actions

Exclude introduced European earwigs from nest sites

How is the evidence assessed?
  • Effectiveness
    not assessed
  • Certainty
    not assessed
  • Harms
    not assessed

Study locations

Key messages

In California, USA, a replicated controlled trial showed that numbers of introduced European earwigs Forficula auricularia resting in solitary bee nest boxes can be reduced using a sticky barrier Tanglefoot. This treatment increased the use of the boxes by native bees.


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

  1. Thirty drilled pine wood solitary bee nest boxes were suspended from 15 valley oak trees Quercus lobata on the Cosumnes River Preserve, near Sacramento, Caifornia, USA, in 1990 (Barthell et al. 1998). The boxes each had twelve 10 cm-deep holes, 0.65 cm in diameter. Boxes were placed in pairs. One on each tree excluded crawling earwigs Forficula auricularia using the sticky barrier Tanglefoot. The treatment substantially reduced the number of earwigs found in the boxes and allowed a greater total number of bee cells (during the peak bee nesting week, there were 134 cells in boxes with Tanglefoot, 45 cells in untreated boxes). The majority of nesting bees in this study were native species of the leafcutter bee genera Megachile and Osmia although introduced species of Megachile were also present.

    Study and other actions tested
Please cite as:

Dicks, L.V., Showler, D.A. & Sutherland, W.J. (2010) Bee conservation: evidence for the effects of interventions. Pelagic Publishing, Exeter, UK


Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Bee Conservation

This Action forms part of the Action Synopsis:

Bee Conservation
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust