Chaetodactylidae

Associated with bee nests and bodies; found within nest cavities of solitary bees including carpenter bees (Xylocopa), mason bees (Osmia), and small carpenter bees (Ceratina). Some species occupy specialized abdominal pouches (acarinaria) on host bees.

Worldwide distribution following host bee ranges; documented from Taiwan, Kinmen, Japan, Egypt, Turkey, Belgium, Brazil (São Paulo), and the United States. One genus (Roubikia) recorded from four localities in São Paulo, Brazil.

• Xylocopa (Alloxylocopa) nr. appediculata - phoretic hostSennertia alfkeni
• Xylocopa (Alloxylocopa) phalothorax - phoretic hostSennertia alfkeni
• Xylocopa (Koptortosoma) ruficeps - phoretic hostSennertia alfkeni
• Xylocopa (Biluna) auripennis - phoretic hostSennertia eximius, Sennertia horrida
• Xylocopa (Zonohirsuta) dejeanii - phoretic hostSennertia eximius, Sennertia lauta
• Xylocopa (Biluna) tranquebarorum - phoretic hostSennertia eximius, Sennertia horrida, Sennertia lauta; introduced to Japan with non-indigenous Sennertia mites
• Xylocopa (Bombioxylocopa) bomboides - phoretic hostSennertia taiwanensis
• Xylocopa aestuans - phoretic hostSennertia egyptiaca; 10–40 mites collected per bee from abdominal acarinarium
• Xylocopa virginica - nest associateSennertia americana
• Osmia cornifrons - cleptoparasitic hostChaetodactylus krombeini; major pest affecting orchard pollination in USA
• Osmia rufa - parasitic hostChaetodactylus osmiae
• Tetrapedia diversipes - phoretic hostRoubikia; mutualistic association, mites attach to mesosoma
• Coelioxoides waltheriae - phoretic hostRoubikia; kleptoparasitic bee
• Ceratina spp. - nest associateSennertia species associated with small carpenter bees in Japan
• Lithurgus - nest associateChaetodactylus species in North America

Phoretic deutonymphs (hypopi) serve as the dispersal stage, attaching to adult bees for transport between nests. In Sennertia egyptiaca, hypopi were the only developmental stage recovered from hosts. Chaetodactylus krombeini hypopi disperse via walking through nest entrances and parasitic wasp emergence holes, with limited flower-mediated dispersal. Chaetodactylus panamensis exhibits dimorphic males.

Phoresy is the primary dispersal mechanism, with hypopi attaching to host bee bodies—particularly the mesosoma or specialized acarinaria. Some species exhibit nest-to-nest walking dispersal independent of phoresy. Chaetodactylus krombeini shows spatial stratification within nests, occurring more frequently in inner portions where female hosts are concentrated. Mites do not enter host cocoons.

Variable relationships with hosts: mutualistic in Roubikia (potential fungal removal from nests, inverse relationship with nest mortality), cleptoparasitic in Chaetodactylus krombeini (causing significant mortality in egg and larval stages of female Osmia cornifrons). Sennertia species show high host specificity, with species groups (japonica-group, cerambycina-group, horrida-group) associated with particular carpenter bee lineages.

Chaetodactylus krombeini is a key pest disrupting maintenance and propagation of Osmia spp. for orchard pollination in the United States, prompting development of fumigant control strategies. Introduction of non-indigenous Sennertia mites via invasive Xylocopa tranquebarorum in Japan poses potential ecological risks to native bee-mite associations.

• mites
• bee associates
• phoresy
• cleptoparasitism
• mutualism
• pollinator pests
• acarinaria

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Phoretic mites (Acari: Chaetodactylidae) associated with the solitary bee Tetrapedia diversipes (Apidae: Tetrapediini)
• Distribution of Chaetodactylus krombeini (Acari: Chaetodactylidae) within Osmia cornifrons (Hymenoptera: Megachilidae) nests: implications for population management
• Note on bee mites of Sennertia Oudemans, 1905 (Sarcoptiformes, Astigmata, Chaetodactylidae) from Taiwan, with descriptions of two new species
• Nest‐to‐nest dispersal of Chaetodactylus krombeini (Acari, Chaetodactylidae) associated with Osmia cornifrons (Hym., Megachilidae)
• Confirming the presence of the phoront species Sennertia (Sennertia) gargantua Zachvatkin (Astigmata: Chaetodactylidae) dispersing on a Carpenter bee in Turkey
• A New Subgenus and Species of Sennertia (Acari,Chaetodactylidae) Associated with the Small Carpenter Bees, Ceratina spp. (Hymenoptera,Apidae) in Japan
• Notes on the biology of anthophorid beeTetrapediaand the miteChaetodactylus panamensisBaker, Roubik and Delfinado-Baker (Acari: Chaetodactylidae)
• Sennertia egyptiaca sp. n. (Acari: Chaetodactylidae), a Phoretic Mite Associated with the Carpenter Bee Xylocopa aestuans Linn.1
• Multivariate discrimination among cryptic species of the mite genus Chaetodactylus (Acari: Chaetodactylidae) associated with bees of the genus Lithurgus (Hymenoptera: Megachilidae) in North America
• The developmental stages and dimorphic males ofChaetodactylus panamensis, n. sp. (Acari: Chaetodactylidae) associated with solitary bee (Apoidea: Anthophoridae).
• Observations on the life cycle ofChaetodactylus osmiae(Dufour, 1839) (Acari: Chaetodactylidae) parasitic on the solitary bee,Osmia rufa(L.), 1758 (Insecta: Hymenoptera) in Belgium
• Ontogeny, systematics and ecology ofSennertia (Amsennertia) americanaDelfinado & Baker, 1976 (Acari: Chaetodactylidae) from the nest of the carpenter bee,Xylocopa virginica(Hymenoptera: Anthophoridae)
• An alien Sennertia mite (Acari: Chaetodactylidae) associated with an introduced Oriental bamboo‐nesting large carpenter bee (Hymenoptera: Apidae: Xylocopa) invading the central Honshu Island, Japan
• Redundant species, cryptic host-associated divergence, and secondary shift in Sennertia mites (Acari: Chaetodactylidae) associated with four large carpenter bees (Hymenoptera: Apidae: Xylocopa) in the Japanese island arc
• Assessment of Potential Fumigants to Control <I>Chaetodactylus krombeini</I> (Acari: Chaetodactylidae) Associated With <I>Osmia cornifrons</I> (Hymenoptera: Megachilidae)