Sightings of caterpillars (larvae) are just as important to the National Moth Recording Scheme as records of adult moths. Indeed, caterpillars provide direct evidence that a species is breeding at a site, so such records can be very important. Records of caterpillars can be contributed in exactly the same way as those of adult moths.
Spotting caterpillars is the easiest recording method for some species. Cinnabar caterpillars, for example, are distinctive and highly visible. Others need to be searched for. This can be done through using a beating tray (or even a turned-up umbrella!), which is held underneath a suitable branch of a tree or small shrub while the branch is given a sharp tap with a stick. Dislodged caterpillars (and other insects) fall onto the tray where they can be examined and identified.
Alternatively a sweep net can be used in long grass. This is swept backwards and forwards through the top of the vegetation dislodging larvae, which can then be removed from the net and examined.
Many larvae are only active by night, so sweeping and beating is often best undertaken at night. Even a torchlight hunt around your own garden at night will reveal moth caterpillars – sure evidence that your patch is good breeding habitat for some moth species.
Having found a caterpillar, the next step is to identify it. Some macro-moth caterpillars are easy to identify but many are not. In such cases, keeping the caterpillar and rearing it through to adulthood (so that you can identify the moth prior to release) may be the best option. Click here for information and advice on rearing caterpillars.