The wall brown butterflies (Lasiommata megera) is reported to have disappeared from its original habitat in southern England. There is some new evidence provided by a study conducted by Belgian scientists that suggests that the rapid decline of the wall brown butterflies may be caused by climate change.

The study proposes that, the recent climate change has resulted in a drastic change in the reproductive cycle of the butterflies, causing them to slowly die. Scientists have observed that the butterflies hatch too late in the season for the new generation to survive, which in turn, leads the butterfly population to keep decreasing every year.

Scientists also noted that new generation of the wall brown butterfly species emerge fully formed later in the year in the months of September or October, instead of their regular emergence in the summer months of July and August. The warmer climactic conditions seem to be forcing the caterpillars to emerge more quickly than before.

In addition, researchers have been lead to believe that due to the butterflies being fully formed closer to the winter months, the butterflies find little or no food for the newer generations to survive. Professor Hans Van Dyck from the Louvain University, who is also the lead of the study, calls this the "developmental trap.".

Richard Fox of Butterfly Conservation said, "This year there were a lot of unusual sightings of moths in the autumn - late spring species suddenly being seen again, but whether the butterfly can adapt and not fall into this trap is a big question - some species adapt and thrive but lots of species become extinct." While Fox is in agreement with the Belgian scientists conducting the study, he also cautioned that climate change may not be the only factor in causing the decline of the wall brown butterflies.