There is a secretive and enigmatic species of moth that will only emerge from their pupa in very specific conditions, on the first day of April. These once in a lifetime conditions are due to be met in the Oxford area today.
The caterpillar of this insect sub species, known as the Lesser April Jester moth (Stulte aprilis dies), will find a sheltered, confined space in which to pupate. In nature, cracks in rocks are an ideal location, but it has adapted to built environments by using the gaps between paving stones. Here it will stay, for years or even decades, until the required environmental conditions are met. When a cold snap follows an unseasonably warm spell, the adult will emerge from the pupa. Entomologists from Oxford University Museum of Natural History believe that the weather we have experienced recently meets these conditions, and is the best chance to see emerging adults for several decades.
The moth will exit the pupal case and, if necessary, will tunnel to the surface, squeezing out through the cracks in the pavement. It will unfurl its glorious, clear wings, displaying the red, blue, green and yellow stripes, on its back, for all to see. It will then fly off to find a mate, to ensure the next generation of this rarely seen insect.
Unfortunately so many jester moths never make it out of their pupa, whether due to the required conditions never being met, or to not having enough energy to dig their way to the surface. If you wish to help, gently inserting and then removing small twigs between paving stones to loosen the soil can help to ease their paths.
The last know sightings in Oxfordshire occurred on Parks Road in Oxford on 1st April 1951. Please let us know if you catch sight of this moth, and even better please share any photos you may take either in the comments below, or via the Contact us page.
Crunchy on the outside 
Published by