Overview
- Huge numbers of migratory painted lady butterflies have arrived in the UK this summer, mated here and produced a new locally born adult generation that is now emerging.
- Experts say a chain of favourable conditions earlier in the year — rain and warmth across sub‑Saharan Africa, North Africa and southern Europe — allowed successive breeding generations to move north into the UK.
- Butterfly Conservation reports counts so far are well above last year and says 2026 could rank among the largest recorded painted lady years, comparable to previous boom years in 1996 and 2009.
- The charity is urging the public to take part in the Big Butterfly Count through early August so scientists can quantify the event and confirm how large this surge is.
- Large local emergences will boost nectar and host‑plant use, help control thistle growth in some areas, and offer a visible example of how weather and breeding success shape cyclical insect population swings.