Carabodidae

Mahunka, S., 1986, A survey of the family Carabodidae C. L. Koch, 1836 (Acari: Oribatida), Acta Zoologica Hungarica 32, pp. 73-135 : 73-78

[The Family Carabodidae ]

The species belonging to the family Carabodidae have the most strongly chitinized body among the Oribatida with a highly varied sculpture by which they are readily distinguishable. The taxa belonging here are spead all over the continents, excepting the Antarctica, many genera are treated as cosmopolites. The great majority of the species live in litter, in decaying wood, only a small number of the species live in moss and in matted grass.

The family was long since separated from the other groups by C. L. Koch (1836), and this fairly coherent group was rarely enriched by new genera, while those genera which proved to belong to other taxa, or were found to be synonyms (Berlese 1913, Trägardh 1931, Willmann 1936) were transferred. However, owing to recent explorations, the number of new genera suddenly increased, the diagnoses of which occasionally presented some difficulty when evaluating the supraspecific categories, leaving the researcher sometimes at loss, consequently, now it is inevitable to make a survey or a partial revision of the group. Thus, besides giving some highly needed redescriptions, I attempt to summarize on the bases of the literature, and partly on the investigated material and the type material that knowledge that definitely refer to the family.

Previously to my investigations the family included 35 genera (as nomen), among them, however, Neocepheus Willmann, 1936, according to our present State of knowledge, is unequivocally a synonym of Carabodes C. L. Koch, 1836 (Balogh 1961), furthermore, two such genera are treated here momentarily ( Podopterotegaeus Aoki, 1969 and Cerocepheus Trägardh, 1931) which, without even detailed examination, have no close relationship with the other genera.

According to my opinion the genus Podopterotegaeus should be transferred to the superfamily Polypterozetoidea Grandjean, 1959, and there provisorily in the family Polypterozetidae , although, a relationship with the families Eutegaeidae Balogh, 1965 or Cepheidae Berlese, 1896 might also be considered. That concerns the genus Cerocepheus some connections are standing with Bornebuschia Hammer, 1966 within the family Eutegaeidae . However, with regard to the structure of the mouthparts and that of the notogaster, further, the overall habitus of the sternocoxal region do not support even provisory solution, consequently, I suggest to separate this taxa under the name of

Cerocepheidae fam. n.

whose type genus is Cerocepheus Trägardh, 1931, belonging to the superfamily Cepheoidea .

My present studies revealed that the genus Carabocepheus Berlese , 1913, described from South Africa, cannot be retained in the family Carabodidae ; this I may safely State, since I have a long series of the only known species of the genus. I have found (see redescription later) that the genus should be transferred to the superfamily Otocepheoidea ,* and under that I errect a new family Carabocepheidae fam. nov.

* According to my opinion the closest allies of the superfamily Carabodoidea should be looked for in this superfamily, based primarily on the structure of the leg, but also on other features.

Besides the suggested transfers, my results of investigations include the erection of three new genera, thus, again, the number of valid genera in the family reaches 35. The State of Diplobodes Aoki, 1958 is not fully solved yet, but since I could not carry out type examination, I am not of the opinion (see identification key) that it is identical either with Gibbicepheus (see Balogh 1961: 276), or Machadocepheus (see Aoki 1970: 419).

I have also found that the family is by far not homogeneous, thus, some clearly delimitable groups of genera might be conceived. In order to make orientation easy and with a view to show the degree of relationship I propose to erect a number of subfamilies, though, obviously, this division might need some further comparative examinations and perhaps finer corrections.

The system of the family, thus, would show the picture on page 00-00.

So far in the separation of the taxa, either at the specific or supraspecific level, only a small number of features has been used, and in the descriptions, even in the comparatively more recent ones, such data as the number of epimeral setae, the position or the absence of the lyrifissure iad are lackirtg or incorrect. During my present investigations I endeavoured to study several new characteristics not studied before. Consequently, the most important identification features in the keys are the following:

1. The number and the position of notogastral setae. This number may vary between 8 and 15, their position is frequently, however, the function of the notogastral structure. I consider it most important how and in what number the setae originate on the humeral apophysis, or in general in the humeral region.

The shape of the setae is considered only at the specific level. True enough this feature as identification character combined with other features might appear and can be decisive in the Separation of genera: Hardybodes , Cavernocarabodes , Klapperiches , Berndobodes . Similarly, the highly variable shape of the sensillus I should not consider decisive in the characterization of genera, let alone Separation from other groups. For the description of setiform organs and setae I use a recently elaborated nomenclature (Mahunka and Zombori 1985).

2. The number of epimeral and anogenital setae. In the family Carabodidae two basic types (2 —1—3— 3 and 3 —1—3— 3) can be recognized, since the 2 —1—3— 3, the 1 —1—2— 4 or 3 —1—2— 4 are only variations of them. Furthermore, on epimere 1 frequently appears 1-1 insertion point asymmetrically in the place of seta la, the only reliable feature is the absence of seta lc.

The basic type for the number of anogenital setae is 4 —1—2— 3. The number of genital setae is between 4 and 10, that of aggenital ones between 0 and 2, adanal 2-3, while the number of anal setae is constantly two pairs.

It is rather questionable whether the number of the genital setae might be considered to be of generic value, since there are many generic pairs ( Gibbibodes - Gibbicepheus , Austrocarabodes - Xenocarabodes , etc.) where the separation is based on this character, otherwise, these pairs are highly similar.

The most important characters will be given in the following table:

I. Cavity or deep hollow in the dorsosejugal region: 0 = absent, 1 = present

II. Notogastral structure: 0 = absent, 1 = present

III. Lamellar cuspis: 0 = absent, 1 = present but short, and 2 = present and long

IV. Tutorium: 0 = absent, 1 = present but weak, and 2 = present and strong or with cuspis

V. Number of notogastral setae

VI. Number of genital setae

VII. Number of aggenital setae

VIII. Position of lamellar setae: on lateral surface of lamellae = 0, dorsal surface of lamellae = 1, in interlamellar position = 2, and in front of lamellae = 3

IX. Position of interlamellar setae: on dorsal surface of lamellae = 0, on the median margin of lamellae = 1, and in interlamellar position = 2

X. Setae in humeral position: absent = 0, one pair present = 1, and two pairs present = 2

XI. Direction of notogastral setae: all backwards = 0, without constant direction = 1, and one or more pairs directed forwards = 2

XII. Position of adanal setae: [[ pictogram ]]

XIII. End of anal plate: without long spine = 0, and with long spine = 1

3. The position of the adanal setae and lyrifissure iad. This feature apparently well characterizes the genera, since it is constant. There may be recognized three basic types and some variations of these. a) ad1 and ad2 in postanal, ad3 in preanal position; b) ad1 in postanal, ad2 is adanal and ad3 in preanal position; c) ad1 in postanal, ad2 and ad3 in adanal position.

It is rather difficult to recognize lyrifissure iad, the sculpture of the ventral plate frequently Covers it. It appears, that, excepting a few cases, when it is wholly reduced, that it is situated always far from the anal plate, and only rarely may it be found close to seta ad3, but then very frequently in paraanal position.

4. The sculpture of prodorsum, the development of the lamellae and the position of prodorsal setae. The lamellae were rarely included in the generic diagnoses, excepting when it was strikingly obvious, but especially the shape or the lack of lamellar cuspis, and together with this the origin of the lamellar setae are surely generic characters. The apex of the lamella may be insignificant, or rounded, sharply pointed, but there are strongly enlarged or reclinate types too. The swellings or the importance of transverse laths resembling translamellae in the interlamellar region are not fully explained, furthermore, there are many transitional forms. These all need further investigations.

The lamellar seta most frequently originates on the outer side of the lamella, but of course, it may appear on the surface of lamella dorsalis, or even on the prodorsal surface. The position of the interlamellar seta also appears to be significant, since it may be inserted on the lamellar surface, in the interlamellar region or on the margin of the lamella. Within a genus its position is reliably constant.

5. The structure of notogaster including the development of the dorsosejugal region. I do not consider the sculpture important at the supraspecific level, on the other hand, apparently the projections, elevations and costulae forming a structure may be decisive in making a choice, which is usually accompanied in the dorsosejugal region by a strong hollow or cavity. Their variation and joint appearance are shown in computer evaluation.

This time I had no opportunity to study the shape of the legs and their chaetotaxic variation. It appears, however, that the shape of seta l" of the genu, or that of setae u, further, the sculpture of the femur could well be used in future identification.