Conservation insights from wild bee genetic studies: Geographic differences, susceptibility to inbreeding, and signs of local adaptation

Abstract

Conserving bees are critical both ecologically and economically. Genetic tools are valuable for monitoring these vital pollinators since tracking these small, fast‐flying insects by traditional means is difficult. By surveying the current state of the literature, this review discusses how recent advances in landscape genetic and genomic research are elucidating how wild bees respond to anthropogenic threats. Current literature suggests that there may be geographic differences in the vulnerability of bee species to landscape changes. Populations of temperate bee species are becoming more isolated and more genetically depauperate as their landscape becomes more fragmented, but tropical bee species appear unaffected. These differences may be an artifact of historical differences in land‐use, or it suggests that different management plans are needed for temperate and tropical bee species. Encouragingly, genetic studies on invasive bee species indicate that low levels of genetic diversity may not lead to rapid extinction in bees as once predicted. Additionally, next‐generation sequencing has given researchers the power to identify potential genes under selection, which are likely critical to species’ survival in their rapidly changing environment. While genetic studies provide insights into wild bee biology, more studies focusing on a greater phylogenetic and life‐history breadth of species are needed. Therefore, caution should be taken when making broad conservation decisions based on the currently few species examined.

Matrix type affects carabid beetle community and trait composition, and intraspecific variation in remnant forests

“…First, a smaller female may produce fewer eggs but of the same size as a larger female. This will affect future population size negatively, possibly leading to inbreeding, genetically more depauperate populations (Kelemen & Rehan, 2021) and/or local extirpation. Second, females in isolated and small habitat patches may produce smaller eggs, which will result in smaller adults in future generations.…”

Biology, Genetic Diversity, and Conservation of Wild Bees in Tree Fruit Orchards

“…Using 10 microsatellite loci analyses, Ballare and Jha (2021) found significant levels of high genetic relatedness in microhabitats, suggesting dispersal at the regional scale [160]. However, other studies have indicated high sensitivity to landscape changes that may limit gene flows as the landscape becomes more fragmented because of human activities [161][162][163][164].…”

The impact of geography and climate on the population structure and local adaptation in a wild bee

“…Despite the fact that wild bee populations are particularly vulnerable to habitat loss (Kline & Joshi, 2020 ; Koh et al, 2016 ; Potts et al, 2010 ) as evidenced by their continued decline on the global scale (Aldercotte et al, 2022 ; Jacobson et al, 2018 ; Zattara & Aizen, 2021 ), bee genetic research has concentrated on a few taxa (primarily Apis and Bombus spp. ), while the majority of solitary species continue to be underrepresented in conservation and genetics literature (Cameron & Sadd, 2020 ; Kelemen & Rehan, 2021 ). As sequencing becomes more accessible and is routinely used to characterize nonmodel species, newly emerging techniques and analyses make it possible to answer previously intractable conservation questions.…”

“…In recent years, there has been an increase in the number of studies aiming to characterize local adaptation in bees. Genome‐wide screening has identified regions under selection across bee genomes (reviewed in Kelemen & Rehan, 2021 ); but research has predominantly focused on traits unrelated to environmental conditions (honeybees: (Cridland et al, 2018 ; Grozinger et al, 2007 ; Harpur et al, 2014 ; Mikheyev et al, 2015 )), sweat bees: (Kocher et al, 2013 ), bumble bees: (Harpur et al, 2017 ) and carpenter bees (Rehan et al, 2016 ). Only a few number of studies have investigated patterns of selection with respect to geographic and climatic variation.…”