Mite‐y bees: bumble bees (Bombus spp., Hymenoptera: Apidae) host a relatively homogeneous mite (Acari) community, shaped by bee species identity but not by geographic proximity

Abstract

1. Parasites can affect the communities of their hosts; and hosts, in turn, shape communities of parasites and other symbionts. This makes host-symbiont relationships a key but often overlooked aspect of community ecology.2. Mites associated with bees have a range of lifestyles; however, little is known about mites associated with wild bees or about factors influencing the make-up of bee-associated mite communities. This study investigated how mite communities associated with bumble bees (Bombus spp.) are shaped by the Bombus community and geographic proximity.3. Bees were collected from 15 sites in Ontario, Canada, and examined for mites. Mite abundance and species richness increased with local bee abundance. Several bee species also differed in mite abundance, species richness, prevalence, and diversity. Locally uncommon species tended to have more mites than other bees. Queen bees had the most mites, and males had more mites than workers.4. Spatial proximity was not a predictor of mite community composition, despite a strong effect of proximity on bee community similarity. 5. On the 11 Bombus spp. examined, 33 mite species were found. Whereas nearly half of these mite species are obligate associates of bumble bees, none was restricted to particular Bombus species.6. The best predictor of mite community composition was bee identity. Although many parasite communities show strong geographic patterns, the communities of primarily commensalistic bee-mites in this study did not. These findings have implications for bumble bee conservation, given that pollen-feeding commensals might become harmful at high densities or act as disease vectors.

Bumble Bee (Bombus vosnesenskii) Queen Nest Searching Occurs Independent of Ovary Developmental Status

“…This idea is supported by our observation that all nest-searching queens with mites had substantial loads (between 9 to 100s of mites), whereas all pollen-collecting queens with mites had loads of five or fewer individuals. The majority of bumble bee-associated mite species do not parasitize bumble bees ( Haas et al. 2019 ), but instead are phoretic, using bumble bees as transportation between nest sites ( Eickwort 1994 ).…”

Patterns of intraspecific morphological variability in soil mites reflect their dispersal ability

“…Morphological stasis in general is considered to be the result of low-standing genetic variation, developmental constraints on the morphospace, and/or a relatively constant ecology of a taxon (Struck et al 2018 ). The microclimate inside belowground bumblebee nests is favorable for mites because of an abundance of stored food reserves and debris (Baumann 2018 ); moreover, it is considered to be little variable even across geographical localities (Haas et al 2019 ), and these stable conditions could explain the morphological stasis of S. acarorum . Another important stabilizing factor leading to the conserved phenotype might be the phoretic lifestyle.…”

Acari of Canada

“…Species records of Laelapidae in Canada are largely unpublished, and possibly 60 additional species remain to be identified or described in the country (Table 2). A few studies of parasites of rodents and other mammals, of bumble bee associates, and soil surveys have increased records of laelapids in Canada (Jones and Thomas 1982, Whitaker and French 1982, Haas et al in press). At least three species are sold as biocontrol agents of greenhouse pests, one of which was discovered in Canada (Beaulieu 2009).…”

“…More restricted ecological surveys have been published for mites in forest canopies of the Pacific coast (Fagan et al 2006, Lindo and Winchester 2006, 2009), in soil and litter (e.g., St. John et al 2002, Déchêne and Buddle 2009, BehanPelletier and Kanashiro 2010, Sylvain and Buddle 2010, Walter and Latonas 2012, Newton 2013, Meehan and Turnbull 2018), peatlands (BehanPelletier and Bissett 1994, Barreto and Lindo 2018, McAdams et al 2018), in dung (Lindquist 1998), and on plants (Forest et al 1982, Beaulieu and Knee 2014), bumble bees (Haas et al in press), beetles (Lindquist and Wu 1991, Knee et al 2013), and birds (Galloway et al 2014, Knee and Galloway 2017b). For certain families or higher taxa of Acari, these publications represent a key source of information for species records in Canada.…”