Survival, reproduction and population growth of the bee pollinator, Osmia rufa (Hymenoptera: Megachilidae), along gradients of heavy metal pollution

Abstract

Bees are one of the most important groups of pollinators in the temperate zone. Although heavy metal pollution is recognised to be a problem affecting large parts of the European Union, we currently lack insights into the effects of heavy metals on wild bee survival and reproduction. We investigated the impact of heavy metal pollution on the wild bee Osmia rufa (Hymenoptera: Megachilidae) by comparing their survival, reproduction and population dynamics along two independent gradients of heavy metal pollution, one in Poland and the other in the United Kingdom. We used trap nests to evaluate the response of fitness and survival parameters of O. rufa. To quantify the levels of pollution, we directly measured the heavy metal concentration in provisions collected by O. rufa. We found that with increasing heavy metal concentration, there was a steady decrease in number of brood cells constructed by females and an increase in the proportion of dead offspring. In the most polluted site, there were typically 3–4 cells per female with 50–60% dead offspring, whereas in unpolluted sites there were 8 to 10 cells per female and only 10–30% dead offspring. Moreover, the bee population growth rate (R0) decreased along the heavy metal pollution gradients. In unpolluted sites, R0 was above 1, whereas in contaminated sites, the values tended to be below 1. Our findings reveal a negative relationship between heavy metal pollution and several fitness parameters of the wild bee O. rufa, and highlight a mechanism whereby the detrimental effects of heavy metal pollution may severely impact wild bee communities.

Metal contaminant accumulation in the hive: Consequences for whole‐colony health and brood production in the honey bee (Apis mellifera L.)

“…In addition to these high levels of pollutants, cavity‐nesting bees were less diverse and less abundant closer to the smelters. The megachilid bee Osmia rufa created fewer brood cells and showed greater mortality along these same pollution gradients . Together, these data suggest that metals can affect insect pollinators other than honey bees.…”

Assessing zinc tolerance in two butterfly species: consequences for conservation in polluted environments

“…enzyme regulation and immunity) (Scrutton et al, 1971;Rink & Haase, 2007), zinc pollution may have negative consequences for pollinators that potentially consume toxic levels of zinc accumulating in plants in human impacted areas (e.g. along roadside ditches or in agricultural fields) (Moro n et al, 2014). Here, we assessed the potential for larval zinc tolerance in wild populations of monarch and cabbage white butterflies.…”

“…For example, zinc can accumulate in urban soils from sources such as industrial combustion, waste incineration, and automobile tire residue (Lagerwerff & Specht, 1970;Jaradat & Momani, 1999;Ramakrishnaiah & Somashekar, 2002). It can mobilise from soil to plant tissue and nectar (Lagerwerff & Specht, 1970) at levels that are potentially toxic to foraging pollinators (Moro n et al, 2014). Although zinc has crucial roles in enzyme regulation and immunity in animals (Scrutton et al, 1971;Rink & Haase, 2007), higher levels of zinc may exert toxicity through the production of oxidative stress (i.e.…”

Trap nests for bees and wasps to analyse trophic interactions in changing environments—A systematic overview and user guide

“…In addition to interaction networks, trap nests are promising tools for long term environmental monitoring (e.g., Steffan‐Dewenter & Schiele, ), pesticide residue (Peters, Gao, & Zumkier, ) or environmental pollution assessments (Moron, Szentgyoergyi, Skorka, Potts, & Woyciechowski, ) and can be used to stock animals for manipulative experiments (e.g., Hudewenz & Klein, ). Nonscientists know various modifications of the methodological approach behind trap nests as “bee hotels” or “insect hotels.” If maintained properly and depletion of local populations due to excessive collecting is avoided, these can have great potential for environmental education (Césard, Mouret, & Vaissiere, ) and citizen science projects (Everaars et al., ).…”

“…Dewenter & Schiele, 2008), pesticide residue (Peters, Gao, & Zumkier, 2016) or environmental pollution assessments (Moron, Szentgyoergyi, Skorka, Potts, & Woyciechowski, 2014) and can be used to stock animals for manipulative experiments (e.g., Hudewenz & Klein, 2015). Nonscientists know various modifications of the methodological approach behind trap nests as "bee hotels" or "insect hotels."…”