Cyrthermannia Balogh, 1958

Miko, Ladislav, 2019, Oribatid mites (Acarina, Oribatida) from French Guyana II. Two new species from superfamily Crotonioidea Thorell, 1876, Acarologia 59 (3), pp. 348-363 : 355-360

Genus Cyrthermannia Balogh, 1958

Balogh (1958) proposed the genus Cyrthermannia for Nanhermanniidae with 6–8 large,

blunt and rounded protuberances on posterior part of the notogaster; and notogastral setae much shorter than those of Nanhermannia , and narrowly lanceolate. This definition is very broad and simple, but genus as such was established and accepted by most authors. A more modern diagnosis of the genus was never given. Some additional characters of the

genus may be extracted from later published determination keys. Balogh (1972) added the following diagnostic characters: notogaster without pteromorphs, areae porosae, sacculi or pori (Apterogasterina-Gymnonota); more than 6 pairs of genital setae (Polytricha), notogaster with

16 pairs of setae (!), concentric or excentric exuviae never present on notogaster, diagastric (with semicircular, medially interrupted suture between genital and anal plates – Nanhermannioidea), notogastral setae simple, whole, without flagelliform apical section, short; posterior portion of notogaster with tubercles. Later, Balogh and Balogh (1992) placed the family within nothroid genera, and precised information about genus as follows: sensillus present, legs monodactyle,

9 g, 2 ag, 2 an, 3 ad, epimeral setal formula 3-1-3-3. Genital and anal plates of brachypyline

type, separated by ventral plate. Anal plates with 2 pairs of setae. Semicircular, medially interrupted suture between genital and anal plates present ( Nanhermanniidae ). Notogaster

with blunt tubercles bearing part of notogastral setae. Notogastral setae short, setiform or leaf-shaped, never bifurcate. Posterior protuberance of prodorsum with one triangular process

on each side. Later, Hammer (1979) proposed a separate genus Bicyrthermannia for species differing from Cyrthermannia by having two distinct projections on the posterior side of interbothridial protuberances, and 16 setae on notogaster (even if her own figure shows only

15 notogastral setae). Later described species of both Cyrthermannia and Bicyrthermannia showed a variability in setation, particularly of genital plates (7–9 pairs of setae), but also

on epimeres (with formulas 3-2-3-3, 3-1-3-4 and 3-2-3-4 also present). Variable number of notogastral setae was reported (from 13 to 16), but from descriptions it is difficult to judge if

all setae were really counted. The figures sometimes indicate the possibility that some setae

may have been omitted. In any case, the most common number of notogastral setae is 15

(and not 16 as given by Balogh, 1972). Given the presence of 15 notogastral setae in several species of Bicyrthermannia , the presence of two large spiniform tubercles on the posterior part

of prodorsum against a single one in Cyrthermannia remains the only distinguishing character

of the genus. Characteristics of legs are usually not given at all in most of described species,

or only very scarce and general information is available. More detailed description of legs is available only for single species of Bicyrthermannia (Badejo and al., 2002).

both posterior and lateral parts of notogaster. Notogastral setae simple, setiform, smooth, some with short spur basally. Epimeral setae short setiform, 9 pairs of genital setae, 2 pairs of short and simple aggenital setae, 3 pairs of adanal setae which are the longest setae on ventral side. Genital and anal plates with longitudinal sclerotised ridge.

Material examined — 2 females collected 2-III- 2012 in mosses, rotting timber and dead leaves on and under fallen tree trunk in tropical rainforest, Saül, Boucle de Monts La Fumée,

near confluence of Crique Cochon and Crique quee Hocco, 150 m, 3°37’66”N, 53°12’00”W

(sample nr. LM-2012-001), French Guyana. Type preserved in acarological collection of Senckenberg Museum in Goerlitz, paratype (damaged, in parts) in collection of the author.

Description — Measurements – Values of holotype given only, as damaged paratype prevented precise measurements. Total body length 500, prodorsum length 186, prodorsum width between tips of pedotecta I 156, notogaster length 314, notogaster width 186.

Integument – ( Figs 3A, 3B , 4C, 4H, 4J ). Body robust, colour dark reddish brown. Integument distinctly ornamented, anterior part of prodorsum on prodorsal field (between prodorsal furrow and rostral setae), as well as whole notogaster and ventral plate foveolate, with foveae framed by mostly simple and not undulated margin, some foveolae may have double margins. Size of foveolae variable (mostly 8–15), largest ones (central on notogaster) not larger than half

of the length of shortest notogastral setae, their mutual distances equal or smaller than diameter

of largest. Some parts of prodorsum (lateral to postbothridial protuberances, axial between setae in and along dorsosejugal furrow smooth, rostral area with fine punctuation. Bothridia

with distinct punctuation, narrow strip between bothridia, postbothridial protuberances and tubercles L, as well as epimeral area with dense fine punctuation and cuticle densely, finely penetrated (“chagrenation”).

Prodorsum – ( Figs 3A , 4A–E ). Rostrum conical, broadly rounded, distally with distinct rostral protuberance (rop), this protuberance centrally with lighter, less sclerotised cuticle. Rostral setae (ro) inserted on sides of this protuberance, short (16), curved mediad and ventrad, smooth. Lamellar setae (le) much longer (37), more or less straight, smooth setiform, inserted on short but distinct transversal lamellar ridge. Distal end of setae le almost reaching base of rostral protuberance in dorsal view. Interlamellar setae (in) same or slightly longer in size (43) and similar in shape as setae le, inserted at anterior border of postbothridial protuberances, insertions on small tubercles or areas with strengthened sclerotisation. Bothridium almost rounded, with rather narrow opening. Sensillus smooth, short (36), not longer than setae le and in, distally bifurcate, with short branches attenuated towards the end. Exobothridial seta ex) (shortest of prodorsal setae (10), thin, hardly visible dorsally. Anterior part of bothridial protuberance with distinct transverse anterobothridial ridge, not longer than diameter of bothridium. Prodorsum anterior to this ridge with rather deep prodorsal furrow, causing significant posterior constriction

of prodorsal field (area behind setae le). Postbothridial protuberances well developed, almost quadrangular, laterally and posteriorly with distinct postbothridial ridge, posteriorly with single, strong, irregularly spiniform or dentiform tubercle (pbt), reaching anterior margin of notogaster or slightly beyond. Between tubercles, less pronounced and deeper positioned cuticular thickening connects the protuberances. Two distinct semicircular lateral ridges (L) present laterally and slightly posterior to postbothridial protuberances, between postbothridial tubercles and pedotecta II, above dorsosejugal groove,. Lateral outline of prodorsum with slightly pronounced angular pedotectum I, pedotectum II more distinct, triangular or irregular. Blunt projection present also on anterior end of acetabulum II. Acetabulum III dorsally with thickened margins.

Notogaster – ( Figs 3A , 4F–H ). Regularly oval in general shape, with well pronounced protuberances on posterior end (protuberances bearing setae h 3 most developed, followed by those bearing h 1 + p 1, p 3 and p 2), but distinct also on lateral sides, diminishing anteriad (largest bearing seta f 2, followed by e 2 and d 2), even setae c 2 and c 3 on small protuberances. Notogastral setae simple setiform, attenuated distally, relatively short (28–40, e 1 longest), setae of rows

c, d, e and f not reaching insertions of following more posterior setae. Lateral and posterior

setae more curved than others. Some of anterior setae (pair c 1 at least) with small, sometimes

indistinct basal spur, this often visible only in detailed lateral view ( Fig. 4F ).

Ventral characters – ( Figs 3B , 4I, 4J ). Gnathosoma relatively short (86), mentum broader

than its length (66 × 46), inverted bell-like, with three blunt projections. Seta a, h, m very short

(around 10), smooth, simple. Tectum of podocephalic fossa (tpf) well developed and broad,

bluntly rounded, projecting distinctly laterad. Lateral outline of epimeral area with several

distinct projections, pedotectum I and II of similar, dentiform or tubercular shape. Posterior to

pedotectum I strong, lateral projection covering partly anterior part of acetabulum II, separated

from pedotectum I by distinct ridge. Similar, but smaller tubercular projection present also

posterior to pedotectum II. Epimeral fields with well visible apodemes, broad and flat, epimeres

I largest. Epimeral setal formula 3-1-3-3, epimeral setae simple, setiform and very short (5–10),

only 4b and 4c slightly longer (17, 20). Genital plates (72 × 35) with longitudinal ridge, well

visible in lateral view, bearing 9 simple setiform genital setae, anterior ones slightly longer (22)

than more posterior (14–18). Two pairs of adgenital setae (ag) very short (14–16). Anal plates

(86 × 31) with longitudinal sclerotised ridge, bearing 2 pairs of very short (11), simple anal

setae, lyrifissure ian not observed. Adanal area well discernible, framed laterally by narrow

semicircular ridge, with 3 pairs of adanal setae, these longer than other ventral setae (26–28),

simple setiform. Lyrifissure iad present in area of adanal ridges, visible better in lateral view.

Lyrifissures ih and ips large, well visible, more-less transverse, positioned anterior to anal

opening, mutual distance of ips smaller than distance of ih.

Legs – ( Figs 4K, 4L ). All legs very strong, robust, with quadrangular or cylindrical

segments, genu and tibia of similar length, both about as long as or only slightly longer than

broad. Femora I and II proximally with distinct, spur-like projection oriented posteriad. Setae

of legs of different shape, those on ventral and lateral side of proximal segments (trochanters,

femora, genua and tibiae) setiform, more or less curved, smooth, dorsal setae of the same

segments usually stronger, claw-like, curved. Setae of tarsi, particularly at distal end and more

on anterior legs than on leg IV, modified, broadened, spiniform or phylliform, with sharp or

sometimes bifid end distally, only proral setae usually longer and not broadened, setiform.

Trochanteral setal formula 1-1-4-1, setal formula of leg I: 1-5-5[1]-6[1]-24(3), setal formula of

leg IV: 1-2-3[1]-5[1]-17. Solenidia small, short (8-10), setiform or bacilliform, slightly curved,

only solenidion ω of tarsus I larger, slightly longer (16) than surrounding setae.

Derivatio nominis — The name bifurcata recalls the specific form of bifurcate sensillus,

which is very unusual within this genus.

Remarks — Genus Cyrthermannia Balogh, 1958 is known mostly from tropical regions

of the world, with some species occuring also in the subtropics. Species of the genus, despite

being easily recognized and distinguished, are mostly insufficiently described (with some

characters simply missing in descriptions), which makes any analysis of taxonomical relations

within the genus quite difficult. Also concepts of the genus have evolved – originally, the genus

was proposed for species of Nanhermanniidae , having visible protuberances at least in posterior

part of notogaster and with generally short notogastral setae (shorter than distance to the setae

positioned in the next posterior row). Later, further genera or subgenera were proposed for

species differing in development of the posterior margin of postbothridial ridge. Species with

a single strongly developed postbothridial tubercle were left in Cyrthermannia , species with 2

such teeth were placed in the genus Bicyrthermannia Hammer, 1979 , and finally species with

posterior margin of postbothridial ridge bearing several smaller tubercles similarly as in some

species of genus Nanhermannia were placed into Nippohermannia Balogh, 1985, a separate

subgenus of Nanhermannia Berlese, 1913 . However, separation of genera only on the basis

of development of posterior edge of prodorsum may not be sufficient taking into account that

Nanhermannia includes both species with a single large tubercle, species with such a tubercle

in combination with smaller tubercles, and species with a set of smaller tubercles, and that

similarly in Cyrthermannia there are some species which have a few smaller tubercles present

laterally to a large tubercle. For further comparison of known species with the new species

described herein, I keep the concept of Cyrthermannia as presently defined.

Among the 11 species of Cyrthermannia , as given by Subías (2004, 2018), there are three

which I consider either doubtful or not belonging to this genus. Cyrthermannia formosana

Tseng, 1982 lacks a single, strongly developed postbothridial tubercle but has a set of numerous

small tubercles on the posterior end of postbothridial ridge. Thus, it should be clearly transferred

and treated as Nanhermannia (Nippohermannia) formosana ( Tseng, 1982) n. comb. Linothrus

perinfamis Tseng, 1982 was described on the basis of tritonymph. The figure ( Tseng, 1982)

indicated that notogastral setae of the nymph are very long, even longer than in some species

of Nanhermannia . It is not clear, on what basis Linothrus Tseng, 1982 was synonymised with

Cyrthermannia and consequently the species L. perinfamis Tseng, 1982 transferred to this

genus by Subías (2004, 2018) as species inquirenda. I consider this placement is doubtful and

both genus and species of Tseng need be considered incertae as sedis. As such, it cannot be

included in following considerations. Finally, the position of the species Hermannia nasata

Warburton, 1912, transferred to Cyrthermannia as species inquirenda by Subías (2004, 2018)

remains unclear, as the original description and figure do not provide the necessary information

– it is not clear if a strong postbothridial tubercle is or is not present, and prodorsal and all

notogastral setae are not mentioned nor depicted. The only indication for placing the species

into Cyrthermannia is the overall form of the body with truncate end of notogaster and body

surface covered by circular foveolae. As such, the species cannot be included in further analysis

and its placement in Cyrthermannia remains questionable.

Thus, disregarding the abovementioned 3 species, 8 species of Cyrthermannia are known.

C. bifurcata can be easily distinguished from all of these by the unusual, short and bifurcate

sensillus. All other species have a more or less clavate sensillus, with either more distinct, or

indistinct and narrow sensillus head. As far as existing information allows analysis, this is not

the only difference. First, the new species has setae in inserted on small but distinct tubercles,

which were not reported in other species. Second, most if not all species have also at least

some epimeral setae distinctly longer, often dilated and sometimes with bristles, while in C.

bifurcata, even the longest of epimeral setae are quite short, smooth and setiform.

The new species belongs to the broader group of species with setae le of the same length or

only slightly shorter as setae in (for the species included see the determination key below), so

that their tips often almost reach insertions of setae ro. Distance of insertions le-ro is therefore

usually much less, in some species closer to double length of seta le. Rostral setae are usually

positioned on a distinct rostral protuberance or on tubercles. Similarly, several species of this

group, including the new species have setae le placed on a short, transverse lamellar ridge.

Another, quite remarkable character is indicated for two species of this group and is present on

the new species – quite distinct and large, semicircular lateral ridge L, a probable analogue of

tubercle L in the lateral postbothridial region, known for example in some Damaeidae ( Miko,

2010, 2015). Unfortunately, in many species this area is not depicted with details and there

is no mention of this structure – so it is not possible to decide definitely, if this character is

specific for the whole group or not.

Within Cyrthermannia , species have 7–9 pairs of genital setae. 9 genital setae appear only

within the group mentioned above, however there are also species with 8 genital setae within

the group. The only known species with 7 genital setae is C. vicinicornuta Aoki, 1965 , which

differs also by position of postbothridial tubercles, which are positioned more medially, closer

to each other than in other species.

Distribution of other characters seems to be irregular among all known species of the genus,

and does not indicate any particular group pattern – the differences are in shape of notogastral

setae (smooth setiform vs. broadened to phylliform), presence of small tubercles on lateral part

of postbothridial ridge (one to three small tubercles present or absent), and development of

cuticular foveolae (round or oval with simple borders vs. modified: irregularly shaped or with

doubled or punctuated margins).

Based on analysis of known morphological character, the following determination key

distinguishes all known species of Cyrthermannia , including the new species described herein:

Figures

Figure 3 Cyrthermannia bifurcata n. sp., adult female: A – dorsal view, B – ventral view (legs only partly depicted). Bar indicating 200 micrometers. Abbreviations and descriptions:1b, 1c, 3c, 4c, 4d – epimeral setae; ad1 – adanal seta 1;ag1 – adgenital seta 1,an1 – anal seta 1;

Figure 4 Cyrthermannia bifurcata n. sp., adult female: A – detail of rostrum; B – seta le in lateral view; C – lateral part of prodorsum; D