Liebstadia similis

Miko, L. & Weigmann, G., 1996, Notes on the genus Liebstadia Oudemans, 1906 (Acarina, Oribatida) in Central Europe, Acta Musei Nationalis Pragae, Series B, Historia Naturalis 52, pp. 73-100 : 90-93

Liebstadia similis (MICHAEL, 1888)

Figs 14-15

The typical form of the species was recently redescribed by Wunderle et al. (1990). It is the largest and most well-known species of the genus, being rather variable in some features, but easily distinguishable from the other species by the following combination of characters (figs 14-15, after Wunderle et al., 1990): body robust and arched; body length 500-565 µm, width 330-360 µm, length:width ratio 1.45-1.60; sensillus (in lateral view) lanceolate; 4 pairs of areae porosae developed; pteromorphs developed as horizontal humeral blades, not bent downwards; length of notogastral setae 30-35 µm; tarsus of leg I with 21 setae (including solenidions and famulus).

One slightly different form was present in our study material, possessing all the most important characters of the nominate form. The differences found are not considered to be at the species level. Because of the variability of the nominate species and an insufficient number of different specimens, we prefer to describe this form without fixing the taxonomical status. Further study may show, whether the different form is of subspecific character.

The main characters of the form (denotated as " longisetosa ") are as follows (figs 16, 17):

Generally with characters of L. similis s. str. Dimensions 493 x 254 µm. Body slender, arched dorsoventrally, with indistinct anterior border. Prodorsum very short in dorsal view. Lamellar and interlamellar setae over 100 µm, rostral setae 63 µm, exobothridial seta 28 µm long. Sensillus lanceolate, 65 µm long, with head length 34 µm and width about 6 µm. Lateral sides of notogaster bent down. Notogastral setae long, mostly between 55-60 µm, seta h2 posteriorly reaching area A3. The female studied was a light coloured, perhaps freshly moulted adult, without eggs. It is possible, that the slender body form may only be a time-limited character occurring during the development of eggs. Also, the most important differential character of the form is the length of the notogastral and other setae. For the similarities with Protoribates serratomarginatus MAHUNKA, 1983 see the discussion.

Material studied:

- 1 female from East Slovak Lowlands (Slovakia), Svätá Mária, corn field on fluvisol, lower soil layer (5-10 cm, sample LM-250-91), 21. 3. 1991 leg, L. Miko, in one of the author's (L. M.) collection.

- 1 female from East Slovak Lowlands (Slovakia), Egreš, corn field on albic luvisol, upper soil layer (0-5 cm, sample LM-541-92). 19. 5. 1992 leg. L. Kováč (the specimen was lost).

Remarks:

We are not able to decide whether " Protoribates longior " sensu Willmann, 1930: fig. 12, redrawn by Ghilyarov and Krivolutsky 1975: fig. 658, belongs to L. similis sensu lato, but the size of 525 µm suggests this. Some other forms, similar to the nominate form, are included in the discussion (see below).