Mitigating the Effects of Habitat Loss on Solitary Bees in Agricultural Ecosystems

Abstract

Solitary bees and other wild pollinators provide an important ecosystem service which can benefit both the agricultural economy and the sustainability of many native ecosystems. Many solitary bees, however, are experiencing decreases in their populations and ranges, resulting in an overall loss of pollinator species richness in many areas. Several interacting factors have been implicated in this decline, including increased pesticide use, climate change, and pathogens, but habitat loss remains one of the primary drivers. The widespread conversion of natural habitats into agricultural landscapes has decreased the availability of adequate nesting sites and floral diversity for many bee species. Large monocultures with intensive production systems often cannot support the populations of wild bees (particularly species with short foraging ranges) necessary to ensure adequate pollination of animal-pollinated crops. Diversifying agricultural landscapes through the incorporation of wildflower plantings, as well as the preservation of remaining natural habitats, may offer a solution, as it has been shown to increase both bee diversity and abundance and the pollination of nearby crops. In this review article, we discuss the various effects of habitat loss on solitary bees and different ways to mitigate such effects in order to conserve bee diversity and populations in agricultural landscapes.

Nest Structure, Seasonality and Female Behavior of Epicharis (Anepicharis) dejeanii Lepeletier (Hymenoptera, Apidae, Centridini) in a Restinga Ecosystem, in Southern Brazil

“…The behavior of spending the night inside the nest herein described was also observed in the two previous study with E. dejeanii (Hiller & Wittmann, 1994;Dec & Vivallo, 2019). By spending more time away from the nest, the female bee leaves it more vulnerable to predators and parasites (Kline & Joshi, 2020). Despite the activity of parasites and predators of bee nests is more intense during the day (Kelber et al, 2005), the behavior of females in spending the night inside the nest could be related to a more effective strategy in protecting their nests.…”

Using the Lonsdorf model for estimating habitat loss and fragmentation effects on pollination service

“…It has been demonstrated that the abundance of wild bees and their diversity in habitats such as farms depend not only on the quality of the farms but also on the distance between the nesting habitats and the patches of their foraging habitat (Ekroos et al 2013;Gathmann et al 1994;Ricketts et al 2008;Steffan-Dewenter and Schiele 2008). In addition to a sufficient amount of nesting habitat, a landscape should provide sufficient floral resources for pollinators (Kline and Joshi 2020).…”

“…Habitat loss and fragmentation make it challenging to find nesting sites and floral resources because bees need their nesting and floral habitats to be adjacent (Kline and Joshi 2020). Habitat loss affects the abundance and diversity of pollinators mainly because of decreasing floral resources (Winfree et al 2011).…”

“…Habitat loss affects the abundance and diversity of pollinators mainly because of decreasing floral resources (Winfree et al 2011). This would be more critical for the wild bees which nest in tree cover (Kline and Joshi 2020). Habitat loss results in decreasing flower density in an area consequently reduce visiting rate (Hegland and Boeke 2006), which can change foraging behavior (Dauber et al 2010).…”

“…Habitat loss results in decreasing flower density in an area consequently reduce visiting rate (Hegland and Boeke 2006), which can change foraging behavior (Dauber et al 2010). Habitat loss also negatively affects the wild bee's accessibility to food resources, and they have to move more distance and take more time to find food, leading to reduced protein content in the larvae (Kline and Joshi 2020).…”