Daytime activity in Androctonus amoreuxi during locust outbreak in Mauritania

 

It is well known that scorpions are mainly nocturnal to avoid sun and high temperatures, and to avoid being eaten and killed by predators. Harington (1981) reported daytime activity in Parabuthus Villosus (Peters, 1862) (Buthidae) in Nambia and refered to similar observation in a few other species. But these are exceptions.

Koutaro Ould Maeno and co-workers have recently published an article describing daytime activity in Androctonus amoreuxi (Audouin,1826) (Buthidae) during a locust outbreak in Mauritania. This happened despite very high surface temperatures. Daytime activity has never been reported in this species previously.

The authors suggest that the unusual high availability of prey has triggered an opportunistic daytime prey capture during the outbreak and this show that this species has the potential of predatory flexibility.

Abstract:
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.

Reference:
Maeno KO, Benahi AS, Jaavar MEH. Daytime predation by a nocturnal scorpion on marching desert locust nymphs during an outbreak. J Orthoptera Res. 2026;35(2):343–6. [Open Access]

Thanks to Matt Simon for informing me about this article!