Parasitellus talparum (=Parasitus favus) (Acari: Parasitidae), phoretic deutonymph, ex Bombus flavifrons, USA: Wyoming, BMOC 99-0624-001 title=
Fig. 1. Parasitellus talparum (=Parasitus favus) (Acari: Parasitidae), phoretic deutonymph, ex Bombus flavifrons, USA: Wyoming, BMOC 99-0624-001. Click to enlarge
Bee Mites : Acari : Parasitiformes : Mesostigmata : Parasitidae

Genus Parasitellus  Willmann, 1939

Parasitellus Willmann, 1939: 534 (Type species Eugamasus (?) ferox Tragardh, 1910 = Acarus fucorum De Geer, 1778 by original designation); Hyatt, 1980: 327 (his synonymy).
Parasitus (Parasitus) non Latreille, 1795: Tichomirov, 1977: 60.
Parasitus non Latreille, 1795: Richards, 1976: 732 (part.); Karg, 1985: 525 (part.).

Type speices Eugamasus (?) ferox Tragardh, 1910 = Acarus fucorum De Geer, 1778 by original designation

Material (show database records).

General Description. This genus includes 11 species that inhabit nests of bumblebees (Bombus) in the Holarctic region (Davydova, 1988; Hyatt, 1980; Karg, 1985; Richards, 1976). Occasionally they occur in beehives or burrows of small mammals (Hyatt, 1980; Crozier, 1989). Deutonymphs are commonly phoretic on the adult bumblebees or cuckoo bumblebees. Since bumblebee colonies are annual and only young queens overwinter, mite deutonymphs are able to distinguish between queens and other castes (workers, males). Although the mites may disperse on all castes of bumblebees, they prefer queens, and never move from a queen to a male. Mites dispersing on workers and males may try to switch to queens later, either during copulation or on flowers, where bumblebees forage (Huck et al., 1998; Schwarz and Huck, 1997).
The species of Parasitellus, although only associated with bumblebees, are not specific to a particular species of host, with species often co-occurring in individual Bombus nests. The lack of host specificity in this group may be the result of host switching in flowers by cockoo bumblebees, or by queens that visit old nests with overwintered deutonymphs. In the nests of a single bumblebee species, mites can disperse due to queen supersedure or invasion of workers or queens from different nests (Richards and Richards, 1976; Tichomirov, 1969a).
The exact nature of the association between these mites and their bumblebee hosts is uncertain, although predatory behavior toward acarid mites and other parasitid mites was suggested (Richards and Richards, 1976). If these mites feed preferentially on potentially damaging acarid mites, they may be beneficial to colony health. In Parasitellus fucorum, males, larvae, protonymphs, and possibly deutonymphs were found to be predatory under laboratory conditions, while pollen was the preferred food for adult females and deutonymphs (Koulianos and Schwarz, 1999).
Variation in many species of Parasitellus involves asymmetry in the shape of the tectum.

Distribution (show map).

Species included.

Key to species of the genus Parasitellus from North America
1Tarsus I not divided ... Parasitellus inquilinobombus
- Tarsus I divided
... 2
2(1) Opisthonotal shield with more than 20 pairs of setae. Tectum with tapered middle point. Apex of tarsus II with 2 lateral spines. Basitarsus IV with 1 long seta (about twice as long as other tarsal setae) ... Parasitellus talparum
- Opisthonotal shield with less than 16 pairs of setae. Tectum with rounded or slightly tapered middle point. Apex of tarsus II with filiform setae. Basitarsus IV with or without long seta
... 3
3(2) Basitarsus IV without long setae. Metapodal shields comma-shaped. Sternal setae smooth. ... Parasitellus hobbsi
- Basitarsus IV with 1 long seta (about twice as long as other tarsal setae). Metapodal shields oval or pear-shaped. Sternal setae serrate or smooth
... 4
4(3) Opisthonotal shield with rounded posterior end and slightly convex lateral edges. Sternal shield narrower (Fig. 1), without longitudinal striations. Sternal setae serrate, sternal setae ST1-3 not inflated at bases ... Parasitellus perthecatus
- Opisthonotal shield triangular. Sternal shield broad, with scarce longitudinal striations. Sternal setae smooth, sternal setae ST1-ST3 distinctly inflated at bases ... Parasitellus sp ex Bombus diligens (Mexico)

* Crozier (1989) lists four unidentified Parasitellus species from bee hives in Nova Scotia (Canada): P. nr. crinitus, P. nr. talparum (as P. favus), P. nr. perthecathus, and P. sp5. Davis and McRory (1987) reported "Parasitus sp. that is not one of the native species" for Canada. This material is not included in the key because it has not been yet studied. Parasitellus papei Karg, 1985 (Greenland) and Parasitus arcticus Karg, 1985 (female only) (Greenland) also should be included here.

Crozier, L. 1989. Melittiphis alvearius (Berlese) and other mites found in honeybee colonies in Nova Scotia. Journal of Apicultural Research.28: 166-168.
Davis, A. & D. MacRory. 1987. Various mites from Ontario beehives. Canadian Beekeeping.13: 209.
Davydova, M. S. 1988. [New species of gamasid mites associated with bumble bees]. Novye i Maloizvestnye Vidy Fauny Sibiri.20: 18-32.
Huck, K., H. H. Schwarz & P. Schmid-Hempel. 1998. Host choice in the phoretic mite Parasitellus fucorum (Mesostigmata: Parasitidae): which bumblebee caste is the best? Oecologia.115: 385-390.
Hyatt, K. H. 1980. Mites of the subfamily Parasitinae (Mesostigmata: Parasitidae) in the British Isles. Bulletin of the British Museum (Natural History) Zoology.38: 237-378.
Karg, W. 1985. Die mit Arten der Gattung Bombus Latreille vergesellschafteten Raubmilben der Gattung Parasitus Latreille 1795 (Acarina, Parasitiformes). Zoologische Jahrbuecher Abteilung fuer Systematik Oekologie und Geographie der Tiere.112: 525-535.
Koulianos, S. & H. H. Schwarz. 1999. Reproduction, development and diet of Parasitellus fucorum (Mesostigmata : Parasitidae), a mite associated with bumblebees (Hymenoptera: Apidae). Journal of Zoology.248: 267-269.
Richards, L. A. 1976. Parasitid mites associated with bumblebees in Alberta, Canada (Acarina: Parasitidae; Hymenoptera: Apidae). I. Taxonomy. University of Kansas Science Bulletin.50: 731-773.
Schwarz, H. H. & K. Huck. 1997. Phoretic mites use flowers to transfer between foraging bumblebees. Insectes Sociaux.44: 303-310.
Tichomirov, S. I. 1969. [Morphological and ecological structure of the genus Parasitus sensu Micherdzinski, 1966 (Gamasoidea, Parasitidae). I. Subgenera Eugamasus Berl., Parasitus Latr., Vulgarogamasus subgen. n.]. Zoologicheskiy Zhurnal.48: 1325-1336.
Tichomirov, S. I. 1977. Family Parasitidae. In [Opredelitel' obytayshchikh v pochve kleshchey Mesostigmata = Identification key to soil-inhabiting mites Mesostigmata], eds. M. S. Gilarov & N. G. Bregetova, 55-107. Leningrad: Nauka.
Willmann, C. 1939. Terrestrische Acari der Nord- und Ostseek├╝ste. Abhandlungen der Naturwissenschaftlichen Verein zu Bremen.31: 521-550.

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Parasitellus talparum, phoretic deutonymph, ex Bombus flavifrons, USA: Wyoming, BMOC 99-0624-001



B. OConnor and P. Klimov ©
Created: April 24, 2012
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