Going out for dinner—The consumption of agriculture pests by bats in urban areas

Abstract

Insectivorous bats provide ecosystem services in agricultural and urban landscapes by consuming arthropods that are considered pests. Bat species inhabiting cities are expected to consume insects associated with urban areas, such as mosquitoes, flying termites, moths, and beetles. We captured insectivorous bats in the Federal District of Brazil and used fecal DNA metabarcoding to investigate the arthropod consumed by five bat species living in colonies in city buildings, and ascertained whether their predation was related to ecosystem services. These insectivorous bat species were found to consume 83 morphospecies of arthropods and among these 41 were identified to species, most of which were agricultural pests. We propose that bats may roost in the city areas and forage in the nearby agricultural fields using their ability to fly over long distances. We also calculated the value of the pest suppression ecosystem service by the bats. By a conservative estimation, bats save US$ 94 per hectare of cornfields, accounting for an annual savings of US$ 390.6 million per harvest in Brazil. Our study confirms that, regardless of their roosting location, bats are essential for providing ecosystem services in the cities, with extensive impacts on crops and elsewhere, in addition to significant savings in the use of pesticides.

Ecosystems Services Provided by Bats Are at Risk in Brazil

“…Even with the aggregate service measure at hand (e.g., number of fruit sets, plant damage), questions of how much diversity is needed for the desired outcome or which species/traits are associated with the effectiveness of service delivery remain unanswered. As such, these results offer evidence for service existence while making good cases for conservation of bat diversity, accounting for the importance of maintaining multiple species contributions to a service (Elmqvist et al, 2003;Aguiar et al, 2021). In other words, the importance of maintaining high provider richness (Isbell et al, 2011).…”

“…These give bats a place in almost every trophic level. While acting as seed dispersers, pollinators, and predators, bats' roles in the ecosystem can be translated into services (Kunz et al, 2011;Aguiar et al, 2021).…”

“…Bats sustain plant diversity (Wang and Smith, 2002) by acting as mobile agents of seed and pollen for hundreds of species (Kunz et al, 2011), facilitating tropical forest succession and accelerating the regeneration of degraded areas such as abandoned pastures (Galindo-González et al, 2000;Muscarella and Fleming, 2007). From a more direct perspective of human welfare, bats play essential roles in agriculture by acting as biological agents of pests suppression in crucial crops, reducing plant damage, and increasing crop yield (Maine and Boyles, 2015;Taylor et al, 2017;Aguiar et al, 2021). Bats also interact mutualistically with economically essential species associated with the survival and cultural reproduction of many social groups (Chévez-Pozo and Ortiz, 1997;Aguiar and Antonini, 2008;Scanlon et al, 2014;Aziz et al, 2017).…”

Could species‐focused suppression of Aedes aegypti, the yellow fever mosquito, and Aedes albopictus, the tiger mosquito, affect interacting predators? An evidence synthesis from the literature

“…A dietary study of four species of urban‐roosting bats in three Brazilian cities is particularly pertinent and indicates that the bats forage largely on agricultural pests in areas just outside the city. Of the five species for which fecal samples were barcoded, three, Nyctinomops laticaudatus , Molossus molossus and Eumops perotis , were found to have consumed Culicidae in a total of 6/43 samples sequenced 163 . Thus, despite being proposed as suitable biological control for mosquito populations, there is substantial evidence that mosquitoes represent only a small proportion of the diet of most bats and that other insects, such as moths, provide better nutritional value.…”

Contrasting Effects of Chronic Anthropogenic Disturbance on Activity and Species Richness of Insectivorous Bats in Neotropical Dry Forest

“…With over 1,400 species distributed globally, bats make up the second largest mammalian order and provide key ecosystem services as seed dispersers (Villalobos-Chaves and Rodríguez-Herrera, 2021), pollinators (Cordero-Schmidt et al, 2021), and pest suppressors (Aizpurua et al, 2018;Vesterinen et al, 2018;Ramírez-Fráncel et al, 2021;Maslo et al, 2022). Despite the fact that the economy largely benefits from services provided by bats (Wanger et al, 2014;Rodríguez-San Pedro et al, 2020;Aguiar et al, 2021), they are highly susceptible to human activity (Voigt and Kingston, 2015;Frick et al, 2019). Indeed, 21% of species are considered endangered or near threatened (IUCN), and globally every four out of five bat populations are decreasing (Welch and Beaulieu, 2018).…”