Daytime predation by a nocturnal scorpion on marching desert locust nymphs during an outbreak

During a desert locust ( Schistocerca gregaria ) outbreak in Mauritania in 2025, we observed a typically nocturnal fattail scorpion ( Androctonus amoreuxi ) emerge from its burrow and capture a marching last-instar locust nymph during the hottest part of the day. After repeatedly stinging the nymph, the scorpion attempted to carry it back to its burrow but abandoned the prey after briefly crossing sun-exposed ground where the surface temperature reached 48°C. Excavation of the burrow revealed another paralyzed locust nymph stored underground, suggesting possible prey storage. In subsequent experiments in bright conditions, this scorpion readily attacked, captured and envenomated eight active locust nymphs in succession. During more than 15 years of fieldwork in the Sahara Desert, we have never observed daytime surface activity by this scorpion species except during desert locust outbreaks. These observations suggest that unusually high prey availability may promote opportunistic daytime foraging by this nocturnal predator, suggesting adaptive predatory flexibility.