probably neutral to beneficial; generalist that feeds on pollen and decomposing or fungus-infested organic matter

Name and classification

Suidasia Oudemans, 1905

Superorder Acariformes » Order Sarcoptiformes » Suborder Oribatida » Infraorder Desmonomata » Hyporder Astigmata » Family Suidasiidae » Genus Suidasia

Type species
Suidasia pontifica Oudemans, 1905

Common synonyms
Aphelenia Oudemans, 1923; Chibidania Sasa, 1952. Suidasia medanensis Oudemans, 1924 (invalid name) is commonly used, but it is a junior synonym of Suidasia pontifica Oudemans, 1905 and should not be used.

Common names
scaly grain mite (Suidasia nesbitti)


Adult: Proral setae (p, q) of tarsi I-IV, enlarged, claw-like (Fig. 8). Internal scapular setae (si) are microsetae, distinctly anterior to posterior margin of prodorsal shield (Fig. 3). Tarsal setae aa present (Figs. 7, 8).

Other diagnostic characters

Adult: Pretarsal ambulacrum not greatly expanded (Figs. 7, 8). Ventral subcapitulum without external ridges (Fig. 6). Body with various patterns: if with small rounded protuberances, then they are coalescent and at least some unequal (Fig 3). Dorsal setae smooth (Fig. 3). Prodorsum with external vertical setae ve present, situated at sides of prodorsal sclerite, near transverse level of vi (Fig. 3). Anus positioned near posterior margin of body (Figs. 1, 4, 5). Coxal apodemes III-IV present (Fig. 4). Empodial claws simple (Fig. 8). Solenidion ω2 situated in basal portion of tarsus, close to ω1 (Figs. 7, 8), or more distal. Setae e and f present on tarsi I-IV, both filiform (Figs. 7, 8). Supracoxal setae lanceolate, with fimbriate margins (Fig. 3). Hysterosomal setae short, distinctly not reaching bases of next setae (Fig. 2).

Bee hosts

Suidasia pontifica has been found in nests of honey bees (Apis) and large carpenter bees (Xylocopa).

Host association level


associated exclusively with bees or their close relative, wasps; cannot live without these hosts


some life stages are associated with bees, while others are not

Facultative or opportunistic

can complete entire life cycle without bees or their close relative, wasps


Host associations, feeding, and dispersal

  • This genus includes generalist species, with all stages living in various habitats (including bee nests), where they probably feed on pollen and decomposing or fungus-infested organic matter; S. pontifica feeds on dead insects.
  • This genus does not form phoretic deutonymphs; they may disperse as feeding stages on insects and other hosts. No records from bees are available.


Suidasia pontifica inhabits a variety of stored products and peridomestic habitats, including house dust, mostly in the tropics. It causes allergic reactions, dermatitis, and rhinitis to humans (Kilpio and Pirila, 1952). It is one of several mite species that is probably responsible for the 'pancake syndrome' (Barrera et al., 2015). This syndrome is known to occur in atopic individuals when eating starchy foods contaminated by mites, which induces moderate or severe, even fatal, allergic reactions.

Suidasia pontifica, as a generalist species, can invade beehives and nests of solitary bees (Xylocopa), and it feeds on dead insects, making it a pest in museum collections. This species has been recorded as part of surveys of bee nest fauna. Biology of this species inside bee nests in unknown. One work reported this species inside honeycombs of Apis cerana and Apis florea in Sri Lanka and suggested that it is a commensal (Koeniger et al., 1983).