We are at a crossroads. We have been finding much fewer Painted Ladies than we had expected. We have only 12 caterpillars for the parasite study and this is too small for any statistics. So what should we do? We had planned to go on from Tafraoute to the town of Tata which is on the edge of the Sahara desert and then on to the Draa Valley which has never been investigated for Painted Lady butterflies. Constanti's theory is that the Souss Valley around Taroudant is the main area in Morocco for overwintering Painted Lady butterflies but the Draa Valley has potential to harbour the butterflies also. However, with our small number of caterpillars we are wondering if we should take the chance on finding nothing by going to the Draa Valley? Or should we go back to Taroudant to collect more caterpillars? Hmmm... We pour over the maps, Eugenie's Royal Irish Academy proposal, Constanti's emails, and our itinerary. All the travelling has been very tiring and it is hard to think clearly. In the end, we decide that our itinerary has flexibility and that will we head to the Draa Valley but spend less days there than we had planned. That way we have some leeway if we need to revisit Taroudant for more caterpillars.

The road from Tafraoute to Igherm is another breath-taking journey. We stop at the top of a pass for a picnic lunch. While we are there we hunt around for scorpions and beetles (there being no thistles to look for Painted Lady caterpillars) and also do a bit of bird watching. We feel like we are on top of the world. It is a stark, beautiful landscape with very few plants or animals. And then! Out of nowhere a butterfly flies by. And not just any butterfly - a Painted Lady! We run to the car and grab the butterfly net but this butterfly is much smarter than us and evades the net. It doesn't matter - we still have the record. But gosh - what is it doing here? It must be undertaking a migration flight up over the Anti-Atlas mountains.

Insect migration is a fascinating science. Countless numbers of insects migrate within and between continents every year. The Monarch butterfly is the most famous of these. Each spring millions of Monarch butterflies migrate from overwintering sites in Mexico to eastern North America. This flight of thousands of kilometres is an incredible feat for such a small animal. Another interesting example is the migration of the Globe Skimmer dragonfly that undertakes the longest migration of any insect from southern India to Africa. But unlike other migratory animals, insects undertake these migrations over a number of generations. So the Monarch butterfly takes four generations to complete its journey. With the Painted Lady we think it takes between six and eight generations. So the great-great-great grandchildren return to the same breeding locations.

Many questions about insect migration remain unanswered. For example, why do insects migrate? How do they know which way to go? What triggers a migration episode? Despite being the most widespread butterfly in the world, the Painted Lady butterfly also has many unanswered questions about its migration. There are a number of different populations of this butterfly in the world. Each completes its migration within a particular region. For the European population, they overwinter in North Africa and spend the spring and summers in the Mediterranean and Northern Europe. Whether there is much genetic exchange with other populations is not known.

And it is the unknown that we venture into in the Draa Valley. Are we using precious time and money to survey the Draa Valley and find nothing? Is finding nothing useful as it will delineate the boundary of the Painted Lady's distribution in Morocco? But perhaps, just perhaps, we will find the Painted Lady in this desolate valley on the edge of the Saharan desert.