Bakerdania

 

HARMFUL | NOT HARMFUL | UNCERTAIN

probably neutral to beneficial; feeds on fungi in bee nests

Name and classification

Bakerdania Sasa, 1961

Taxonomy
Superorder Acariformes » Order Trombidiformes » Suborder Prostigmata » Infraorder Eleutherengona » Hyporder Heterostigmata » Family Neopygmephoridae » Genus Bakerdania

Type species
Pygmephorus cultratus Berlese, 1904

Common synonyms
Neopygmephorus Cross, 1965

Diagnosis

Female: Posterior margin of posterior sternal plate entire (Fig. 7). Leg I subequal with leg II (Fig. 2).

Other diagnostic characters

Female: Tergite C not covering prodorsum (Fig. 5). Two pairs of propodosomal dorsal setae (Fig 5). Leg I four-segmented, with tarsus and tibia I fused forming tibiotarsus (Figs. 8). Two pairs of setae on each coxae I-II (Fig. 6). Claw I medium-sized, not striated (Figs. 8). Tarsus IV with claws (Fig. 9). Trochanter IV subquadrate (not triangular), distinctly constricted in middle part (Fig. 9). Setae d of femur I modified, slightly widened (Fig. 8). Pinnaculum on tibiotarsus I absent or present, bearing 1 seta (tc'') or wide, bearing several setae (B. amplus). Basal part of gnathosoma not elongated. Palps shorter than basal part of gnathosoma (Fig. 4). Bothridial setae, present, clavate (Fig. 5). Median genital sclerite absent (Fig. 7).

Species identification

This is a species-rich genus, with no dichotomous keys available except for regional keys to species from Central Europe (Krczal, 1959) and the Palaearctic (Sevastyanov, 1978). The only species found in association with bees, Bakerdania amplus (=Neopygmephorus amplus), can be identified by solenidion ω1 on tibiotarsus I with a characteristic bubble-shaped widening.

Similar genera

This genus is in need of revision; some species currently classified in Bakerdania should be placed in new genera (hence the boundaries of the genus Bakerdania may change in the future). Very similar to Parapygmephorus (subgenera Parapygmephorus and Sicilipes) but differs from them by trochanter IV distinctly constricted in middle part (not distinctly constricted in Parapygmephorus and Sicilipes). Differs from Parapygmephorus (subgenus Sicilipes) by its tibiotarsus I not enlarged (enlarged in Sicilipes). Bakerdania, Parapygmephorus and Sicilipes differ from Kerdabania by having an entire posterior margin of posterior sternal plate, whereas in Kerdabania it is tripartite, with 3 large lobes.

Distribution

Cosmopolitan. The only species found on bees (Bakerdania amplus) is from Germany.

Bee hosts

Bakerdania amplus, the only species of this genus collected from bees, has been found in a nest of a "wild bee."

Host association level

Permanent

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

Temporary

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

unknown, probably facultative

Host associations, feeding, and dispersal

Unknown for the single species found in bee nests.

Biology

This genus is species-rich. Species of Bakerdania are found in a wide variety of forest and cultivated soils and other organic and plant substrates. They are probably fungivorous, with various degrees of specificity. Females of some species were found phoretic on Coleoptera hosts. Unusual phoretic associations of females of Bakerdania elliptica include terrestrial isopods (Colloff and Hopkin, 1986). Bakerdania elliptica may rely on phoresy in order to gain access to patches of fungal mycelia which they would otherwise not encounter. All the attached mites are females and non-feeding while dispersing on hosts. Males are extremely rare and occur only in leaf litter.