Brevipalpia minima, Zacharda, 1980

Andre, H. M., Zacharda, M. & N'Dri, J. K., 2010, From Parataxonomy To Molecular Data: The Case Of Rhagidiidae (Acari) From Belgian Soils, Acarologia 50 (4), pp. 501-512 : 502

Comparison of B. minima and H. macrostella

The two species belong to the Rhagidiidae . They are both minute soft-bodied mites which are collected in similar habitats. B. minima is generally longer than H. macrostella , total idiosomal length 338-380 µm vs. 241-309 µm ( Zacharda, 1980; Ducarme et al., 2004b) ( Fig. 1 , 2 ). Contrary to many other species ( Fig. 1 ), both mite species have prodorsal trichobothria clavate, but the density of barbules covering the trichobothria is different in the two species. The trichobothrias arise from a sclerite which extends from the naso to the anterior part of the opisthosoma ( Fig. 3 ).

The microsculpture of this sclerite differs between the two species ( Fig. 3 ). Besides, a nodular microstructure is observed on the integument between chelicerae and on the paraxial faces of palps and legs ( Fig. 3 , 4 ), the shape and density of nodules are characteristic of the species.

The other major distinctive characters between B. minima and H. macrostella rely mostly on the unique diversity of forms of the subcapitulum, the chelicerae, the palps, the tarsi I, the rhagidial organs and the leg chaetotaxy as described hereafter.

Figures

FIGURE 1: Dorsal aspect of different soil Rhagidiidae. A – Brevipalpia minima Zacharda, 1980; B – Coccorhagidia clavifrons (Canestrini, 1886); C – Hammenia macrostella Zacharda, 1980; D – Parallelorhagidia evansi (Strandtmann and Prasse, 1976); E – Crassocheles virgo Zacharda, 1980 (from Zacharda 1980).

FIGURE 2: Brevipalpia minima and Hammenia macrostella in ventral view. Scale bar = 50 µm.

FIGURE 3: Prodorsum of Brevipalpia minima and Hammenia macrostella. Scale bar = 25 µm.

FIGURE 4: Brevipalpia minima Zacharda, 1980: A – dorsum, B – venter, C – trichobothrium, D – palp, E – tarsus I in lateral aspect, F – chelicera, G – subcapitulum, H – rhagidial organ I (from Zacharda 1980).