Distribution and conservation of semiaquatic bugs (Hemiptera: Heteroptera: Gerromorpha) in the states of Alagoas and Sergipe, northeastern Brazil

Abstract

Aquatic and semiaquatic Heteroptera (Insecta: Hemiptera) are globally distributed and inhabit a wide range of lentic and lotic water bodies. Most semiaquatic bugs (Heteroptera: Gerromorpha) live on the water surface, among hydrophytes, or on the margins of limnic habitats. These predatory insects are particularly diverse in the Neotropical Region, but they are still very poorly known in the northeastern region of Brazil, especially in the Caatinga biome. Their distribution and conservation in the area have very recently started being explored. Based on literature data and samples obtained in the northeastern Brazilian states of Alagoas and Sergipe, we present here potential geographic distribution models for 17 species of semiaquatic bugs and a potential species richness map. We designed fieldwork to reduce sampling bias by including different mesoregions of the states and areas both within and outside local protected areas (PAs). Our results reveal that gerromorphan populations exhibit distinct distribution patterns in the study area, with several species showing high habitat specificity. Furthermore, they are generally well covered by the existing PAs and higher potential richness is likely related to the environmental integrity of these areas, which might play a crucial role in locally conserving aquatic insects. Furthermore, we show that a less dense vegetal cover negatively influenced the richness found in lotic systems. This highlights the importance of maintaining and effectively managing the PAs already established in these states.