The potential of cleptoparasitic bees as indicator taxa for assessing bee communities

Abstract

International audienceMany factors affect bee diversity and abundance, and knowledge of these is crucial for maintaining healthy bee communities. However, there are few means to fully evaluate the status of bee communities; most are based on monitoring species richness and abundance and do not consider the diverse life histories of bees. We propose that functional diversity of bee communities offers a more consistent means of evaluation and suggest that cleptoparasitic bees in particular show much promise as indicator taxa. Cleptoparasitic bees play a stabilising role within bee communities. They represent the apex of bee communities and are the first guild to respond to disturbances, are easily distinguished as such and are diverse enough to be representative of entire bee communities. The diversity and abundance of cleptoparasites in relation to all bees is indicative of the status of the total bee community, and monitoring them should form an integral part of assessing bee communities

Local and landscape effects on bee functional guilds in pigeon pea crops in Kenya

“…These bee species, commonly live within natural or semi-natural vegetation. Cavity-nesting bees have been shown to respond negatively to intense agriculture, presumably in response to loss of nesting habitat availability (Sheffield et al 2013).…”

Increasing the conservation value of powerline corridors for wild bees through vegetation management: an experimental approach

“…Large population sizes are usually linked to lowered risk of extinction, and diversity of pollinators has been found to increase pollination services, likely through redundancy (Steffan-Dewenter and Westphal 2008;Winfree et al 2008). Many would argue, however, that richness and abundance are not the only (or even the most critical) gauge of healthy bee communities and functional group analysis should be included in any assessment (e.g., Sheffield et al 2013a). Analyzing the impact of vegetation management on the representation of particular groups/guilds based on body size, sociality, trophic level, nest site preferences, foraging specificity, etc., can tell us more about community health than richness measures.…”

“…Further, as social bees have been shown to be more severely impacted by isolation from natural habitat and patch size (Jauker et al 2013;Williams et al 2010Ricketts et al 2008;Klein et al 2002), we would expect that the increased presence of social species would be an indication of successful management. The presence of parasitic bee species (cleptoparasites of other bee species) are also relevant, as they add a trophic level and are thought to only persist where populations of their hosts reach a stable threshold, likely due to a sufficient resource base (see Sheffield et al 2013a). Therefore, we should look for a management protocol that increases the number of parasites.…”

An expert-assisted citizen science program involving agricultural high schools provides national patterns on bee species assemblages

“…-Species richness: This is the number of species caught over 1 year at the sampling site; -Species dominance: This is the proportion of the most abundant species (also known as Berger-Parker index); -Ecological traits: Each species was described according to three ecological traits that have been shown to be important to determine the response of bees to environmental disturbances (e.g., Moretti et al 2009;Williams et al 2010;Winfree et al 2011;Sheffield et al 2013;Rader et al 2014;Kremen and M'Gonigle 2015): reproducti ve strategy, trophi c speci ali zati on, and nesting behaviour. Information was compiled from the literature (Westrich 1989;Amiet et al 1999Amiet et al , 2001Amiet et al , 2004Amiet et al , 2007Amiet et al , 2010Michener 2007).…”

“…In each case, the first four environmental variables were derived from the High Nature Value (HNV) data and calculated at the municipality level. The proportion of herbaceous semi-natural elements was derived from Corine Land Cover data (2006) and calculated at two spatial scales (100 and 500 m radius centred on sampling sites) This aspect has been little investigated in bees (but see Sheffield et al 2013;Marini et al 2014). Thus our results that dominance at the species, genus and parataxonomic levels decreased with crop diversity provides new insights on the influence of agricultural practices on bee assemblages.…”