''Chaetodactylus krombeini'', (Krombein's hairy-footed pollen mite), was described by
Karl Krombein and E. W. Baker in the 1960s. The mites are about 0.5 mm across, with the females larger than the males. Pollen mites are a
kleptoparasitic pest of
Megachilid
Megachilidae is a cosmopolitan family of mostly solitary bees. Both that their pollen-carrying structure (called a ''scopa'') is restricted to the ventral surface of the abdomen (rather than mostly or exclusively on the hind legs as in other be ...
solitary bees, with ''Ch. krombeini'' found with ''
Osmia lignaria'' of
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, (the Blue Orchard
Mason Bee). Pollen mites do not feed on bees, but rather their provisions, and are harmful because they consume the food resources and starve or stunt the developing larvae; there is evidence that pollen mites also directly harm the egg by puncturing it.
The common name is somewhat misleading, as pollen mites consume more nectar than pollen. Both their feeding habits and their size differs significantly from ''
Varroa destructor'', the mite very harmful to the
European Honey Bee. Although both are classified as mites, varroa mites are more closely related to ticks and only distantly related to ''Chaetodactylus''.
A mason bee, upon emerging from its nest, may be burdened by hundreds of hitchhiking pollen mites. While mites do shed off bees after leaving the nest, including during mating, studies find that mites are rarely picked up when visiting flowers.
The mite's life cycle is necessarily tied to the bee's reproductive cycle, but the mechanisms are not fully understood. They have both mobile and immobile phases that are reproductive and non-reproductive, at times simultaneously. ''Ch. krombeini'' appears to be more successful in humid conditions, possibly because the food mass stays moist longer under these conditions; heat and dehydration is sometimes used for pollen mite pest management.
Identification
Because accurate identification of different pollen mite species is exacting and microscopic, and several host bees are in commerce and shipped regularly, it is likely that ''Ch. Krombeini'' is over-identified. Even experts express reluctance in specifying mites, such as reported in a study of ''Osmia pumila''.
In Japan ''Chaetodactylus nipponicus'' is linked to the hornfaced bee, ''
Osmia cornifrons'', and in Europe ''Chaetodactylus osmiae'' is associated with the red mason bee, ''
Osmia rufa''.
But, ''Ch. osmiae'' has been recorded in eastern Oregon, where ''O. rufa'' is not known.
Gallery
File:Chaetodactylus krombeini Osmia lignaria pollenmites enlarged.jpg, ''Chaetodactylus krombeini'' infestation of an ''Osmia lignaria'' nest cell.
File:Covered in Mites.jpg, Mason bee covered in ''Chaetodactylus krombeini'' mites
File:BMOC-15-0510-001 Chaetodactylus krombeini f m in copula.jpg, ''Chaetodactylus krombeini'' mites copulating
File:Ontogeny Chaetodactylus krombeini.jpg, Life stages of ''Chaetodactylus krombeini''; non-phoretic deutonymph and male not shown.
File:BMOC-15-0510-001 Chaetodactylus krombeini f supracoxal sclerite TM3030 1662(x1.0k).jpg, ''Chaetodactylus krombeini'' female lateral propodosoma showing enlarged supracoxal sclerite. This trait is diagnostic for the family Chaetodactylidae.
References
''Chaetodactylus_krombeini''bugguide.net. Species ''Chaetodactylus krombeini''
{{Taxonbar, from=Q56076906
Sarcoptiformes
Parasitic acari
Animals described in 1962