Frédéric McCune

Bio: Frédéric McCune is an academic researcher from Laval University. The author has contributed to research in topics: Pollinator & Ecology. The author has an hindex of 1, co-authored 5 publications receiving 13 citations.

Response of wild bee communities to beekeeping, urbanization, and flower availability

Abstract: Wild bees provide pollination services and are currently declining at the global scale. A potential cause for this decline is competitive interactions with domestic honey bees. Urban beekeeping, a fairly new activity, is rapidly gaining popularity. In contrast with agricultural and natural areas, the extent of competition between honey bees and wild bees in urban areas is unclear. The objectives of this study were to quantify the impact of honey bees, urbanization, and the availability of floral resources on wild bee communities. We hypothesized that honey bees exert negative impacts on wild bees, that floral resources favor wild bee communities and mitigate the negative impacts of competition with honey bees, and that the influence of heat islands, used as a proxy for urbanization, varies between wild bees with their functional traits (nesting behavior). We tested these hypotheses with a data set of 19,077 wild bee specimens collected using colored pan-traps at 25 urban sites in 2012 and 2013. We investigated community and population patterns after accounting for imperfect detection probability. We found no evidence of competition between wild and domesticated bees. Our analyses indicate mixed effects of urban heat islands across species and positive effects of floral resources. We conclude that cities can allow the coexistence of urban beekeeping and wild bees under moderate hive densities. However, it will remain crucial to further investigate the competitive interactions between wild and honey bees to determine the threshold of hive densities beyond which competition could occur.

Supplying honey bees with waterers: a precautionary measure to reduce exposure to pesticides

Abstract: Water is essential for honey bees (Apis mellifera L.), but contaminated sources of water in agricultural environments represent a risk of exposure to potentially harmful contaminants. Providing clean water to honey bees could be an efficient and cost-effective measure for beekeepers to reduce bee mortality associated with pesticides and improve the health of their colonies. The main goal of this study was to design a waterer prototype to fulfill the water requirements of honey bees and to evaluate the potential of this waterer in improving colonies’ health in agricultural settings, through mitigating the possible impact of an exposure to pesticides from puddle water. We tested the preference of honey bees regarding water composition and waterer prototypes, among which honey bees showed a strong preference for salted water and a poultry-type waterer. Our waterer models were quickly adopted and intensively used through the season in both the context of honey production in field crops and pollination services in cranberry crops. However, in neither context did the use of waterers reduce worker mortality nor increase overall colony weight. Our waterers provided bees with water containing fewer pesticides and were associated with reduced risks of drowning compared to natural sources of water. Our study suggests that the use of waterers fulfills an important requirement for honey bees and represents an interesting and convenient precautionary measure for beekeepers.

Insecticidal effect of Bacillus pumilus PTB180 and Bacillus subtilis PTB185 used alone and in combination against the foxglove aphid and the melon aphid (Hemiptera: Aphididae)

Abstract: The foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), and the melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), are among the serious insect pests found in greenhouses. The efficacy of microbial control against these insects has been demonstrated and can be enhanced by the combination of different microbial agents. This study evaluated the efficacy of Bacillus pumilus Meyer and Gottheil PTB180 and Bacillus subtilis (Ehrenberg) Cohn PTB185, used alone and together, to control these two aphids both in the laboratory and in greenhouse on tomato, Solanum lycopersicum Linnaeus (Solanaceae), and cucumber, Cucumis sativus Linnaeus (Cucurbitaceae), plants. The results from the laboratory tests showed an increase in mortality induced by all biological treatments. In the greenhouse, all treatments induced mortality rates significantly higher than that of the control for A. solani. Similarly, all treatments performed better than the control against A. gossypii, significantly reducing its reproduction. Furthermore, we found no additive effects when mixing products nor negative interactions affecting survival for the bacteria investigated. These microorganisms therefore have potential for use in biological control.

Onion thrips, Thrips tabaci (Thysanoptera: Thripidae), reduces yields in indoor-grown cannabis

Abstract: Cannabis (Cannabis sativa L.; Rosales: Cannabaceae) is a newly legalized crop and requires deeper insights on its pest communities. In this preliminary study, we identified a thrips species affecting indoor-grown cannabis in Canada and tested its impact on plant yield. We used three levels of initial infestation (zero, one, and five thrips) on individual plants grown in two growing mediums: conventional substrate or substrate containing the biostimulant Bacillus pumilus Meyer and Gottheil (Bacillales: Bacillaceae). We found that the onion thrips, Thrips tabaci (Lindeman) (Thysanoptera: Thripidae), is proliferating in indoor-grown cannabis. Furthermore, our results showed that fresh yields were higher for the plants that initially received zero thrips compared to those that initially received five thrips. Moreover, the biostimulant only marginally helped reduce the impact of thrips. We highlight the importance for growers to carefully monitor thrips infestations in indoor-grown cannabis. Finally, we emphasize the need for more research related to the impact of pests on cannabis yields and safe means of pest control for this strictly regulated crop.

More losses than gains in ground-nesting bees over 60 years of urbanization

Abstract: Along with agricultural intensification, urbanization is often implicated in bee declines worldwide. While the vast majority of studies investigate how bee assemblages respond to urbanization across different spatial scales, very few attempts have used a temporal comparison to evaluate the impact of urbanization. The city of Curitiba in southern Brazil is unique for having long-term data of bees, and thus is a good model for studying urban temporal changes. The main goal of this study is to investigate how a ground-nesting assemblage responded to six decades of urban growth in Curitiba. In this time lapse the city population grew from 140 thousand to almost 2 million inhabitants. We demonstrate a 94% decline in nest abundance, a 35% decline in species richness, and a 24% decline in phylogenetic diversity from 1955 (T1) to 2018 (T2). Temporal beta diversity values between T1 and T2 were very high and most sampling sites were dominated by losses in nest abundance. All sampling sites changed similarly with losses in nesting substrates (i.e. exposed soil) and a substantial increase in surrounding impervious surface. This study exhibits how depletion of nesting substrates combined with increases in urban cover can affect pollinators, a concerning scenario as most bees nest in friable soil and thus are strongly susceptible to urbanization. We emphasize that urban planning policies to protect ground-nesting bees are essential to preserve the important ecological service of pollination in cities.

Grassland restorations improve pollinator communities: a meta-analysis

Abstract: Natural grasslands are being destroyed at an alarming pace, but land managers are actively working to restore these habitats Many of these efforts focus on restoring plant diversity but often do not consider responses of higher trophic levels such as pollinators, which provide crucial ecosystems services We conducted a meta-analysis of 25 large-scale studies to examine the effects of grassland restorations on pollinator communities Specifically, we compared pollinator communities in restored, degraded and remnant grasslands to determine if restorations improve pollinators from a degraded state and if they fully restore them to remnant values We found that grassland restorations significantly improved both pollinator abundance and richness as compared to degraded grasslands Additionally, pollinator abundance and richness did not significantly differ from remnant sites, indicating a near full recovery Sub-analyses found that factors such as pollinator taxa, restoration age, and mode of land degradation all influenced the magnitude of recovery In particular, lepidopteran abundance increased more than bee abundance in these restorations Older restorations (> 10 years) showed the strongest improvements in pollinator communities This research highlights the importance of grassland restorations in supporting not only plant diversity but also pollinators

To bee or not to bee.

Abstract: Can you spell words like tyrannosaurus or guillotine? If you think you can, you may make it into the Times Spelling Bee team! This year the team was composed of Luke Shortland (7G), and Vishal Shah, Alec Walker and me (all 7B). Miss Haire was our team coach. We all got into the team after a really competitive process; this included spelling words out on paper, followed by words spelt out loud. The words varied from jettison to conscientious. I felt that it was more difficult to spell out loud than on paper, which was annoying as the whole point of the spelling bee was to spell out loud! It was hard to get used to, yet practice with Miss Haire every Friday helped us improve our oral spelling skills, which made us confident of success in the local heats. Every Friday lunchtime we practised spelling words of increasing difficulty out loud. “Ecclesiastical” was a team favourite!