Before treating OPM, the first step is to look for infestations and confirm the presence of caterpillars. If found, there are a variety of treatments available for affected trees, including:
Removal of OPM caterpillars or larval nests is another method to control the spread of this pest. Caution must be taken when coming in contact as there are many risks to human health.
Below is a table that shows the recommended treatment options for the life-cycle stages of development of the oak processionary moth. The table sets out the life cycle of OPM. Note that the timings of the various stages are approximate, reflecting seasonal and local variation. In some years, S1 may appear in mid-April and S4 by the first week of May.
S = Life cycle stage. Timing can be heavily influenced by prevailing climatic conditions. The table provides an estimation and should be used only as a guide.