Revision of the family Carabodidae (Acari, Oribatida) XII. Yoshiobodes camerunensis sp. n. and Rugocepheus costaricensis sp. n.

Abstract Yoshiobodes camerunensis sp. n., collected in Cameroon, is the first species of this genus reported from the Afrotropical region. Diagnostic characters include lamellae terminating in a bridge and not in lamellar tips; cup-shaped bothridia, bothridial ring present; rostral setae cochleariform, smooth; lamellar setae slightly lanceolate, barbate; fifteen pairs of notogastral setae; c3 lanceolate, rounded end, with longitudinal shallow grooves; other notogastral setae curved lanceolate-cochleariform. Rugocepheus costaricensis sp. n. is the third species of the genus to be described, and the first collected outside the African region. Prodorsum presents a Y-shaped structure; elevated interlamellar process, superior flat zone; lamellae lacking lamellar tips; fourteen pairs of notogastral setae; four notogastral furrows, and an unpaired elevated central area devoid of setae. Both species are described and illustrated based on adult specimens, studied by means of optical and SEM microscopy.


Introduction
Extensive collection materials of the family Carabodidae sampled in Africa (Cameroon, Kenya, Zimbabwe, Rwanda, South Africa, Madagascar, Gabon, Comoros, Republic of the Congo, Democratic Republic of the Congo, Nigeria, Ghana); South and Central America (Argentina, Chile, Brazil, Paraguay, Uruguay, Bolivia, Peru, Ecuador, Costa Rica, Martinique, Honduras, Guadeloupe, Trinidad-Tobago), and Asia (Vietnam, China, Cambodia, Sri Lanka) are housed in the Museum national d'Histoire naturelles, Paris (MNHN), the Museum d'Histoire naturelles Geneva (MHNG) and in the senior author's personal collection. Studies of this material have been ongoing, in parallel to the redescriptions of type material of the various genera started in 2013.
The taxonomy of the genus Yoshiobodes is complex. This genus comprises 12 species and is divided into three subgenera: Yoshiobodes, which includes eight species with Pantropical (excluding Ethiopic) and Subtropical (Holarctic Southern) distribution; Berndobodes with two species from Borneo, and Dongnaibodes with two species from Vietnam (Subias 2017). According to Reeves (1997), the type species is Yoshiobodes irmayi (Balogh & Mahunka, 1969), with Neotropical distribution, and the comparison of Y. irmayi collected from North America and from St. Lucia, West Indies, revealed that they are conspecific.
This genus is very difficult to study using optical microscopy due to their small size, cuticular microsculpture, cerotegumental layer, particular topography, and setal particularities. The complimentary use of Scanning Electron Microscopy (SEM) is fundamental to understanding and clarifying several aspects of this fascinating group of Carabodidae. The contribution by Reeves (1997) is remarkable, and the redescription of the type species Y. irmayi is given here for the first time including both adults and immatures, as well as SEM micrographs. Yoshiobodes camerunensis sp. n. is the first species of this genus found in the Afrotropical region.
The second species, Rugocepheus costaricensis sp. n. is described from Costa Rica. Two species of this genus are known previously from Africa, namely Rugocepheus formosus Mahunka, 2009 and Rugocepheus joffrevillei Fernandez, Theron & Rollard 2013, both from Madagascar.

Materials and methods
The techniques used in the light and scanning electron microscopic investigations of the examined specimens follow those proposed by Fernandez et al. (2013).
The SEM observations were made using Scanning Electron Microscope FEI-Quanta Feg 250, with 10 Kv and working distant (WD) variable.
Measurements taken: total length (from tip of rostrum to posterior edge of notogaster); width (widest part of notogaster) in micrometers (μm). Leg setation studies making use of standard, polarized and phase contrast microscopes are provisional, due to the fact that only adult specimens were available for study. Setal formulae of the legs include the number of solenidia (in parentheses); tarsal setal formulae include the famulus (ε).
Lateral region (Figures 1, 5, 14). A thorough study of the lateral aspect was imperative for observation and interpretation of several structures. Conical e.i.p inclining slightly upwards (Figures 1, 5); lam clearly discernible (Figures 1, 5, 10, 11, 13, 15); le inserted on lam, behind level of ro setae ( Figure 15); no lamelar tips present; le setae inserted some distance from where the apical part of lam reaches the rest of prodorsum; this zone forming a bridge where le setae can be concealed (Figures 10, 15); large, laterally expanded Tu at same level as Pd I ( Figure 15); Tu with upward curving margin; several depressions ( Figure 15) visible on Tu and zone between Tu and Pd I, with variation in shape and depth ( Figure 15 (Figure 1, indicated by arrow). Pd II: small lamina, rounded apex; dis a triangular protuberance (Figure 34). Many circular to ovoid depressions (dep), delimited by cuticular thickenings, occurring behind, on top of and on lower part coxa IV up to genital opening (Figures 1, 5, 21).
Remarks. The positioning of the le setae during activation of the protection mechanism is interesting: these setae are shielded under the lamellae, but are also further protected by the cerotegumental layer (Fig. 10). Protected by the external margin of Lam (figure 1), and concealed in the deepest zone of the s.tu.d, Legs I are difficult to study. Yoshiobodes camerunensis is the first species of this genus from the Afrotropical region. Y. irmayi (Balogh & Mahunka, 1969), redescribed by Reeves 1997, is close to Yoshiobodes camerunensis sp. n. Principal similarities: presence of p.p.d on prodorsum; rectilinear microsculpture between d.sj; microsculpture c 1 , c 2 setae and behind setae c 1 , c 2 ; number of notogastral setae; shape of notogastral setae; shape of in setae. Principal differences: prodorsal cuticular microsculture, shape of prodorsum; characteristics of l.l.f; shape and characteristics of ro setae; shape and characteristics of le setae; microsculpture of epimeral zone; structure s.fu.
Colour. Specimens without cerotegument: females light brown to brown.
Remarks. Rugocepheus costaricensis sp. n. displays important differences to Rugocepheus joffrevillei Fernandez, Theron & Rollard, 2013 and R. formosus Mahunka, 2009. Principal differences: beak-shaped rostrum; distribution of furrows and elevated areas on dorsal zone of notogaster, central elevated area without setae; ventral zone with discidium differing in shape; genital and anal zone very different.
Discussion. Using SEM allows significant progress in detailed descriptions, as the small body size, morphological characteristics, and complex topology makes Yoshiobodes a difficult genus to study. This complexity is compounded by brief, somewhat cryptic original descriptions and illustrations. Reeves (1997), contributed much to our understanding of this genus, specifically due to studies of both adults and immatures. Reeves also originally pointed out the following characters with reference to the adult prodorsum of Yoshiobodes: "Dorsosejugal depression deep, slit-like, widest medially" (page 316) (in our series of papers on the revision of the family Carabodidae, this depression is designated as the "posterior prodorsal depression (p.p.d) " Fernandez et al. 2013), but this structure was not noted again until this present paper. The analysis by Reeves of the work done by Bellido (1978) is noteworthy as he analyses the depression observed on the prodorsum in protonymphs, deutonymphs and tritonymphs of Carabodes. Reeves (1997) indicates: "The scalloped edged depression on the prodorsum of protonymphs, deutonymphs and tritonymphs appears similar to the foveate sclerite found in immatures described by Bellido (1978) of Carabodes willmanni Bernini, 1975." The most recent generic diagnosis by Ermilov et al. 2014 is based on data from Mahunka (1986) and additions by authors, but the type specimen, Y. irmayi (Balogh & Mahunka, 1969) does not seem to have been studied. SEM and optical microscopy studies by Reeves (1997) on adults as well as ontogenetic studies, were also not discussed. Reeves 1997 indicated that, on comparison, "a specimen of Y. irmayi from St. Lucia (on loan from the Hungarian Natural History Museum) to North American material showed them to be conspecific".