The substantial elimination of airborne sulphur dioxide pollution has reportedly allowed for the recovery and geographical spread of lichens and algae, which footman moth caterpillars largely consume. This change has been linked to the thriving of footman moths.
However, a more realistic message suggests that the balance of major airborne pollutants has shifted since the 1990s, from sulphur dioxide to nitrogen oxides. Nitrogen oxides, a byproduct of internal combustion engines among other sources, are said to benefit lichens and algae, and consequently footman moths.
Despite this, environmental pollution from various sources is reportedly contributing to widespread and massive declines in the numbers of most groups of moths and other insects in Britain today. Footman moths are considered an exception and not a representative model for other insect populations.