The use of moth traps is generally a non-lethal method of surveying what species are using a site. Some moths will occasionally expire in the trap but not very often and the numbers won’t have a significant effect on the population as a whole.
However, it is important that certain precautions are taken in order to minimise suffering of animals which have been attracted to the trap. The following is a list of ideal precautions to be taken when running moth traps of varying kinds either for surveying purposes or for public events:
- Do as little damage to the surrounding habitat as possible.
- No more specimens should be taken than is necessary to confirm difficult species identification.
- Keep adequate records of any species encountered, including who (if anyone) confirmed the identification, life stage, location and method of trapping (if relevant).
- Records should then be sent to the appropriate county recorder and/or local record centre.
- Sugar should never be applied to tree trunks etc. where lichens/epiphytes could be affected. Wine ropes are preferable.
- If the light trap could potentially cause suspicion or confusion then the relevant authorities should be notified (e.g. police/coastguard) as well as any near neighbours.
- Always seek permission from the landowner or occupier before trapping on private land and always report findings to the landowner afterwards.
- Avoid touching moths’ wings directly. Children often like to hold some of the bigger moths at trapping events but should only do so for short periods and avoid touching the wings when doing so.
- Put moths in clear glass/plastic containers for close inspection.
- Only put one moth in each container and ensure the container is big enough.
- If moths are very active they can be put in fridge or cool box for a short time.
- Moths can be kept in a container in a fridge for up to two days while they are identified.
- Moths should be released carefully out of sight of birds in thick or long vegetation, ideally at dusk after having been kept in cool shady conditions. They should be released near (but not at) the trap site but also be spread as wide as possible around the immediate area in order to minimise losses to birds.
- To avoid birds learning to come and eat moths where you have attracted them:
- Check (or cover) trap at dawn.
- Use bird scarers (don’t leave in place for longer than necessary).
- Regularly change moth trapping site.