Abstract
The impact of climate change is intensifying in Amazonia through, among other causes, the higher frequency of both severe droughts and floods due to El Niño and La Niña events as well as an Atlantic influence. Over a 25-year period (1997–2021) we examined in French Guiana the impact of different climatic parameters on the most frequent social wasp, Polybia bistriata (Polistinae). As it commonly nests on Clusia grandiflora (Clusiaceae), its nests are easily found. Heavy rainfall, particularly during the 1999–2000 La Niña episode, negatively affected this social wasp species as the percentage of Clusia sheltering an active P. bistriata nest decreased from ≈ 40% during the pre-2000 period to zero in 2021. We conclude that extreme wet seasons related to climate change translated into the decline of this species and likely were detrimental to many other polistine wasps of north-eastern Amazonia.