Les insectes déclinent-ils aussi dans les Petites Antilles ? Étude diachronique 1997-2022 de la diversité de deux familles dans le sud de la Guadeloupe (Lepidoptera, Sphingidae ; Coleoptera, Scarabaeidae)

Are insects also declining in the Lesser Antilles? A 1997-2022 diachronic study of the diversity of two families in southern Guadeloupe (Lepidoptera, Sphingidae ; Coleoptera, Scarabaeidae). In 1997, Christophe Sautière used a light trap to study several insect families in and around the Guadeloupe National Park. At nine sites, Sphingidae (Lepidoptera) and Scarabaeidae (Coleoptera) were surveyed, with precise abundance quantification. In 2021-2022, 25 years later, the survey was repeated at the same locations, to assess any changes that had occurred during this period. Abundance, diversity and community composition were compared between the two periods. For Scarabaeidae, no significant differences are found. For Sphingidae, mean abundance per night is significantly lower in 2021-2022, with a loss of 85% in abundance (Cohen effect size d = - 0.74). Overall diversity across all nine sites and composition did not change significantly. The limitations of this study are discussed, the low number of repetitions of light trapping, the absence of intermediate monitoring and the difference in power of the lamps used between the two periods, 25 years apart.