Lost in the Iguidi erg

In 1989, along with several colleagues from CIRAD, we had to travel in the Tamesna, in the northern saharian Niger, to study habitats and populations of the Desert locust (Schistocerca gregaria Forsk.) less than a year after the huge invasion of 1987-1989. Our guide was Ayuba Ali, a former prospector of the OCLALAV, a " Joint Locust and Bird Control Organization", covering all of South Saharan countries. Ayuba was a connoisseur of the Desert locust and had a perfect knowledge of all the desert zones of Niger. Among his " exploits ", he had spent a year in the massif of Termit in the heart of the Ténéré desert – a particularly isolated place - to study low density populations of this insect.

Ayuba therefore guided us. Arrived in the region of the erg Iguidi we began several surveys on the edge of the erg, in areas where the Schouwia purpurea (a plant species of the Cruciferous family, appreciated by the Desert locust), reached an impressive height. Some locusts actually took advantage of this manna; some camels grazed at their ease. Then it was decided to cross the erg from south to north, on approximately 50km of sand dunes. In this area, inter-dune habitats could be interesting for the locust. After the rains, he could find a suitable soil for egg laying and a very favorable vegetation for young larvae development.

We started crossing the erg northward, from an interdune to another. Magnificent but monotonous landscape. Then, of course, after a few kilometers we get stuck in the sand. Then another time. We had no radio, only one vehicle, no one knew about our itinerary ... but we had an outstanding guide ! Soon, all our sand waffle boards (unfortunately plastic) eventually break. After 24 hours spent searching, in the interdunes, sandstone slabs to be placed under the wheels, we finally were able to leave ... till the following dune. After a few hundred meters, we were stuck in the sand again, and we were able to overcome after only 24 hours of hard work. Yet, in this desert we were not alone: a camel-driver came by. He kept us company for a few minutes and then seeing that all was well (at least for him!), he left us for the infinity of the desert. All this makes routine of the Saharan zone. Nevertheless, after getting stuck in the sand several times, having covered 200 meters in 2 days, and as we were a bit discouraged, we made a U-turn... abandoning the locusts to their fate. It was decided that Iguidi will keep its secrets !