Spatial aggregation of phoretic mites on Bombus atratus and Bombus opifex (Hymenoptera: Apidae) in Argentina Pablo Revainera, Mariano Lucia, Alberto Abrahamovich, Matias Maggi To cite this version: Pablo Revainera, Mariano Lucia, Alberto Abrahamovich, Matias Maggi. Spatial aggregation of phoretic mites on Bombus atratus and Bombus opifex (Hymenoptera: Apidae) in Argentina. Api- dologie, Springer Verlag, 2014, 45 (5), pp.579-589. 10.1007/s13592-014-0275-4. hal-01234756 HAL Id: hal-01234756 https://hal.archives-ouvertes.fr/hal-01234756 Submitted on 27 Nov 2015 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. 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Apidologie (2014) 45:579–589 Original article * INRA, DIB and Springer-Verlag France, 2014 DOI: 10.1007/s13592-014-0275-4 Spatial aggregation of phoretic mites on Bombus atratus and Bombus opifex (Hymenoptera: Apidae) in Argentina 1 2,3 2,3 Pablo REVAINERA , Mariano LUCIA , Alberto Horacio ABRAHAMOVICH , 1,3 Matias MAGGI 1Laboratorio de Artrópodos, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, 7600, Mar del Plata, Argentina 2División Entomología, Museo de La Plata, Universidad Nacional de La Plata, Paseo del Bosque s/n, 1900FWA, La Plata, Argentina 3CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Rivadavia 1917, C1033AJ, Buenos Aires, Argentina Received 1 June 2013 – Revised 9 January 2014 – Accepted 5 February 2014 Abstract – Mites have been observed on the bumblebee’s body and inside their nest for over 150 years, and parasitic relationships between them have occasionally been reported. One of the most interesting animal associations between mites and bees is phoresy. At present, no study has evaluated the distribution patterns of phoretic mites on bumblebees nor the factors that might be influencing such association. The main goal of this research was to determine whether an aggregation of external mites on bumblebees is influenced by (a) the phoretic mite load per bee, (b) the host species, (c) the caste of bumblebee, (d) the interaction between mite load and bee species, and (e) the presence of a suitable physical place for the mites to accommodate on the bee body. The following mite species were recorded on Bombus atratus and Bombus opifex: Kuzinia laevis, Kuzinia americana, Kuzinia affinis, Kuzinia sp., Pneumolaelaps longanalis, Pneumolaelaps longipilus, Scutacarus acarorum, and Tyrophagus putrescentiae. Our results indicate that Kuzinia mites have a strong preference for a particular region on the propodeum, which has shorter hairs than on most areas of the body. In addition, generalized linear model analysis demonstrated that mite aggregation was influenced by the caste and host species. bumblebees / phoretic mites / aggregation 1. INTRODUCTION association could lead to different interactions, ranging from negative impacts on the bees to the Mites have long been associated with bees, often potential benefits to them (Chmielewski 1971). The showing a close relationship among particular taxa, best-known negative association between mites probably as a result of a coevolutionary process and bees is that between Varroa mites and (Klimov et al. 2007). Records of these relationships honeybees. These ectoparasitic mites feed on the are widely available, but the biological understand- bee’s hemolymph, weakening the bee and often ing of such relationships is still limited. A mite-bee leading to the death of the colony (Sammataro et al. 2000). The genetic structure of the Varroa popula- tions, its reproduction, and its negative impacts on Corresponding author: P. Revainera, the bee colonies have been widely reported (Maggi [email protected] et al. 2009, 2010, 2011b, 2012;Rosenkranzetal. Manuscript editor: James Nieh 2010). However, the associations of mites on other 580 P. Revainera et al. bees are poorly understood (e.g., Fain et al. 1999; natural and agricultural ecosystems Fain and Pauly 2001; Waiter et al. 2002). (Abrahamovich et al. 2001; Goulson 2003). Mites One of the most interesting animal associations have been observed on bumblebees and in their is phoresy. Farish and Axtell (1971) proposed that nests for over 150 years (Husband 1968). These phoresy is a phenomenon in which one animal associations have been studied by several authors actively seeks out and attaches to the outer surface including Chmielewski (1971, 1977, 1998), of another animal for a limited time during which O’Connor (1988), Houck and O’Connor (1991), the attached animal (termed the phoretic) ceases Schwarz et al. (1996), Huck et al. (1998), both feeding and ontogenesis. Such attachment Chmielewski and Baker (2008), and Maggi et al. presumably results in dispersal from unsuited to (2011a). These ecological interactions among suited areas for further development, either of the mites and bees vary in form and complexity, individual or its progeny. Phoresy occurs, for ranging from strictly phoresy to parasitism example, in some species of bees that can carry (O’Connor 1988), but no studies have evaluated one or several mite species, usually the hetero- the distribution patterns of phoretic mites on morphic deutonymphs (non-feeding instars), bumblebees and the factors that influence them. which complete their life cycles inside the bee Reports of mites other than Varroa infesting nest. Both bees and mites might benefit from this honeybees suggest that mite distribution on the association. Mites reach a safe place for reproduc- bee body is aggregated and significantly differs tion (besides ensuring food resources and protec- from a Poisson distribution (Le Conte et al. 1990; tion against potential predators), and bees become Floris 1991; Donzé et al. 1996). The authors of favored by the mites, which feed on potentially these studies indicated that mite aggregation harmful microorganisms from the surface of the suggests differences in the chemostimuli trigger- pollen-nectar sources (Schwarz and Huck 1997). ing infestation, such as higher production of The presence of special areas or “acarinaria” on kairomones from the bee host, deposition of the bee body in which mites are transported chemical trails, or emission of an aggregation provides a secure place for them. In many species pheromone by the infesting mites. of solitary bees (genera Ctenocolletes of the family Here, we studied external mites on bumblebees Stenotritidae; Thectochlora and Lasioglossum of to determine whether aggregations are influenced Halictidae; and Xylocopa, Ceratina,and by (a) the phoretic mite load per bee, (b) the host Tetrapedia of Apidae), this acarinarium is the species, (c) the bumblebee caste, (d) the interac- result of modified external morphological struc- tion between mite load and bumblebee species, tures (McGinley 1986;O’Connor and Klompen and (e) the presence of a suitable physical place 1999;Engel2000; Klompen et al. 2007). No for mite accommodation on the bumblebee body. information concerning the acarinaria on bumble- We hypothesized that mites modify the density of bees has yet been reported. As suggested by their aggregation on the host bee accordingly to Klimov et al. (2007), true acarinaria are not simply (a) density-dependent phenomena, (b) the caste of induced by the mites’ presence, but from changes the bumblebee species that they are infesting, and in the host’s body over evolutionary time to (c) the area of the bee body on which they accommodate the mites. Nevertheless, aggregate. In addition, we provide information on Abrahamovich and Alzuet (1989) defined another the ecological relationships of mites infesting type of acarinarium: a functional one, where mites Bombus in the neotropical region. are safely transported even when no drastic morphological changes are observed on bees. 2. MATERIALS AND METHODS Whatever the location of an acarinarium in the bee or its morphological complexity, a conse- 2.1. Bombus survey quence of this structure is the grouping of mites. Bumblebees (genus Bombus Latreille) are We surveyed mites on a total of 668 bumblebee among the most efficient insect pollinators in specimens of Bombus atratus and Bombus opifex Aggregation of mites on Argentinean Bombus 581 from three entomological collections in Argentina: patterns of mite aggregation, only Kuzinia mites were IFML (Fundación e Instituto Miguel Lillo, Tucumán), used to establish the presence/absence of a visibly IADIZA (Instituto Argentino de Investigaciones de recognizable cluster of mites. We chose these mites las Zonas Aridas, Mendoza), and MLP (Museo de La because they present heteromorphic deutonymphs, Plata, La Plata). These bumblebee specimens are dry- which stay attached to their host even after they die. mounted (pinned) and were collected between 1945 The presence of mite aggregation was only recorded and 1986 from ten provinces in Argentina: Buenos when more than two mites were found attached in the Aires, Catamarca, Córdoba, Entre Ríos, Formosa, same place and were in close contact with each other. Jujuy, La Rioja, Mendoza, Salta, and Tucumán. Mites scattered on the bee body were not considered