Bee Mites : Acari : Acariformes : Trombidiformes : Pyemotidae : Pyemotes

Pyemotes beckeri Krczal, 1957

Pyemotes beckeri Krczal, 1957: 451, Figs 28-30; Cross and Moser, 1975: 734; Cross et al., 1981: 181.
Pyemotes ventricosus (non Newport, 1850): Krombein, 1967: 369.

Distribution. USA: Arizona, Florida, Louisiana, Maryland, Mississippi, New York, and Virginia; Germany (type locality) (Cross and Moser, 1975; Krczal, 1957; Krombein, 1967).

Biology. In the United States this species was recorded from Lyctus planicollis LeConte, 1858 (Coleoptera: Lyctidae) in Mississippi, Scolytus multistriatus (Marsham, 1802) (Scolytidae) in Louisiana, and a wasp nest in Virginia (Arlington) (Cross and Moser, 1975). Krombein (1967) reported "Pyemotes ventricosus" from an array of sphecid and vespid wasps, as well as from nests of megachilid bees infested in the laboratory. Because his material included numerous samples from nests of wasps from Arlington (Virginia), and Cross and Moser (1975) reported Pyemotes beckeri from a wasp nest from exactly the same locality, we assume that Krombein's material in fact was misidentified. Unfortunately, without Krombein's material we can not confirm this assumption or check whether it is represented by one or more species. Unverified records of Pyemotes beckeri from North American Hymenoptera include Tripargilum clavatum (Say, 1837) (Maryland, New York, Virginia), Tripargilum tridentatum tridentatum (Packard, 1867), Tripargilum tridentatum archboldi (Krombein, 1959) (Florida), Trypoxylon frigidum Smith, 1856 (Virginia), Psenulus pallipes parenosas (Pate, 1944) (Virginia) (Sphecidae), Stenodynerus krombeini Bohart, 1953 (New York), Euodynerus foraminatus apopkensis (Robertson, 1901) (Virginia) (Vespidae), Prochelostoma philadelphi (Robertson, 1891) (Virginia, infested in laboratory), Aschmeadiella bigeloviae (Cockerell, 1897) (Arizona, infested in laboratory), Aschmeadiella bucconis denticulata (1878) (Arizona, infested in laboratory), Osmia pumila Cresson, 1864 (infested in laboratory, the nest is probably from Maryland) (Megachilidae) (Krombein, 1967).
Outside North America, this species was found on larvae of Anobium punctatum (De Geer, 1774) (Coleoptera: Anobiidae), Sitophilus granarius (Linnaeus, 1758), and Sitophilus oryzae (Linnaeus 1763) (Curculionidae) in Germany (Krczal, 1957).
Krombein (1967) noted that "normal" females move relatively rapidly. They are able to leave an infested nest after the host insects have been killed, and enter adjacent nests through the breached entrance plugs and cell partitions. The mites attack eggs, larvae, pupae, as well as paralyzed prey stored by wasps (insects and spiders). This species of Pyemotes can cause serious problems in laboratory settings, as mite females can easily infest cultures of bees through the split halves of the trap nests.

Cross, E. A., J. C. Moser & G. Rack. 1981. Some new forms of Pyemotes (Acarina: Pyemotidae) from forest insects, with remarks on polymorphism. International Journal of Acarology.7: 179-196.
Cross, E. A. & J. S. Moser. 1975. A new, dimorphic species of Pyemotes and a key to previously-described forms (Acarina: Tarsonemoidea). Annals of the Entomological Society of America.68: 723-732.
Krczal, H. 1957. Sytstematik und Ökologie der Pyemotiden. In Sytstematik und Ökologie Mitteleuropäischer Acarina. 1(1). ed. H.-J. Stammer, 385-823. Leipzig: Akademissche Verlaggesellschaft.
Krombein, K. V. 1967. Trap-nesting wasps and bees: life histories, nests, and associates. Washington, D.C: Smithsonian press. 570 pp.



B. OConnor and P. Klimov ©
Created: April 27, 2012
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