Bilobella matsakisi Cassagnau, 1967

Dányi, László, 2010, Review of the genus Bilobella Caroli, 1912 in the Balkan Peninsula with description of a new species (Collembola: Neanuridae), Zootaxa 2605, pp. 27-44 : 37-41

Bilobella matsakisi Cassagnau, 1967

Figs 39–44 , Tab. 3–5

Bilobella matsakisi Cassagnau, 1967: 50 ; Cassagnau 1968: 299, Figs 2 F, 3, 5A, 6A, 6C, Pl. 1a; Cassagnau 1979: 188; Cassagnau et al. 1985: 9, Figs 1 , 2 , 4 , Pl. 5c, Tab. 1–2 ; Traser & Kontschán 2004: 76, Figs 6–11 , Tabs 3–4 .

Diagnosis. Dorsal tubercles well developed, hemispheric in shape. Colour orange. Buccal cone elongated. Labral chaetotaxy 4/2, 4. Maxilla with apical tooth. Ant. I. with 8, ant. II with 12 chaetae. Absence of chaetae D and O on head. Tubercle (Di+De) of head with 4 chaetae. Tubercle De of th. I with 2 chaetae, tubercle De of th. II–III with 4 chaetae. Integumental granulation arranged into separated fields on papillae. Tubercle L of abd. IV with 8–11 chaetae. Tubercle (Di+De+Dl) of abd. V with 11–12 chaetae. Claws without teeth.

Material examined. 1 female on slide (collpr–441): Greece, 2009/82, Larisa county, Ossa Mts, Karitsa, oak forest S of the village, 520m, N39°49.615’ E22°46.174’ leg. L. Dányi, J. Kontschán & D. Murányi, 9.iv.2009. 1 female on slide (collpr–443): Greece, 2009/50, Arkadia county, Magouliana, spruce forest SW of the village, 1130m, N37°39.404’ E22°06.976’ leg.L. Dányi, J. Kontschán & D. Murányi, 6.iv.2009. 1 female on slide (collpr–438), 1 female on three slides (collpr–451 (body), collpr–486 (head), collpr–487 (legs)), 1 female in alcohol (coll–648): Greece, 2009/63, Arkadia county, Kalavrita, Vouraikos River, ruderal vegetation W of the city, 685m, N38°02.154’ E22°05.899’ leg. L. Dányi, J. Kontschán & D. Murányi, 7.iv.2009.

Description of specimens from the Peloponnesus, Greece. Habitus similar to Bilobella aurantiaca ( Caroli, 1910) with dorsal tubercles hemispheric in shape ( Fig. 39 ). Body length (without antennae) 2.75– 4 mm. Tertiary granulation well developed, with reticular pattern forming by the grouping’s of granules into separated fields ( Fig. 39 ) on papillae. Reticulation on ventral side of body present ( Cassagnau 1968: Fig. 6 A).

Colour of the body orange in living specimens, but fading to white in alcohol. 2+2 medium, unpigmented eyes.

Dorsal ordinary chaetae: macrochaetae Ml thickened, narrowly sheathed, apically arc-like and distinctly serrated ( Cassagnau 1968: Fig. 6 C); macrochaetae Mc with similar morphology, mesochaetae thin and pointed.

Head. Buccal cone elongated. Labrum with ventral sclerifications as in Fig. 43 . Labrum chaetotaxy 4/2, 4 ( Fig. 43 ). Chaetotaxy of labium same as in B. mahunkai ( Tab. 3 , Traser & Kontschán 2004: Fig. 10 ). Maxilla styliform with minute apical tooth ( Figs 40, 42 ) and with two coherent lamellae. Base of maxilla without styliform appendage. Mandible thin with one basal, one medial and one two-branched apical tooth ( Cassagnau 1968: Fig. 2 F). Ant. I and II with 8 and 12 chaetae respectively. Ant. III with 14 chaetae and 5 S– chaetae. Ant. III and IV fused dorsally. Antennal III–organ as in Fig. 44 , organite of antenna IV as in B. mahunkai . Dorsal ( Fig. 44 ) and ventral chaetotaxy of ant. IV similar like in B. mahunkai with difference only in the relative smaler size of S3 and S4. Apical vesicle distinct, trilobed. Ant. IV with 8 moderately thickened S–chaetae, of which S7 and S8 distinctly longer than other sensilla ( Fig. 44 ). S1 and S2 weaker. S4 of similar size as S3, not as well developed as in B. mahunkai . Chaetotaxy of head as in Cassagnau (1968: Fig. 3 ), Traser & Kontschán (2004: Figs 8, 11 ) and as in Tab. 3 . Chaetae D and O absent.

Tubercle Number of chaetae Types of chaetae Names of chaetae Cl 4 Ml F Mc G Mc Di2, De2

(Dl+L+So) 9–10 Ml, Mc, me impossible to recognise Number of other cephalic chaetae: Vi, 6; Ve, 9; labrum, 4/2, 4; labium, 10, 0x; ant. I, 8; ant. II, 12; ant. III, 14+5s; ant. IV, 8S+i+or+12mou.

Thorax, abdomen, legs. Dorsal chaetotaxy of thorax and abdomen as in Fig. 39 and Tab. 4. Th. I: De with 1Mc, 1Ml; Dl with Ml. Th. II and III: Di with 1Mc, 1Ml; De with 2Mc, 1Ml, 1S; Dl th. II with 1Mc, 1Ml, 1S, 1ms; Dl th. III with 1Mc, 1Ml, 1S; L with 2Mc, 1Ml. Abd. I–III: Di with 1Mc, 1Ml; De with 1Mc, 1Ml, 1S; Dl with 1Mc, 1Ml; L abd. I with 2Mc, 1Ml; L abd. II with 1–2me, 2Mc, 1Ml; L abd. III with 2–3me, 2Mc, 1Ml. Abd. IV: Di with 1Mc, 1Ml; (De+Dl) with 2Mc, 2Ml, 1S; L with 3–5me, 3Mc, 2Ml. Abd. V: (Di+De+Dl+L) with 7Mc, 4Ml, 1S. Abd. VI: (Di+De+Dl+L) with 4Mc, 3Ml.

Ventral chaetotaxy of th. and abd. as in Tab. 4. VT with 4–5+4–5 chaetae. Furca rudimentary, with 8–10 mesochaetae, without microchaetae.

Terga Legs

Di De Dl L Scx2 Cx Tr Fe T th. I – 2 1 – 0 3 6 13 19 th. II 2 3+s 2+s+ms 3 2 7 6 12 19 th. III 2 3+s 2+ s 3 2 8 6 11 18

Sterna

Abd. I 2 2+ s 2 3 VT: 4–5

Abd. II 2 2+ s 2 4 –5 Ve: 2 – 3 Ve1: 5–6

Abd. III 2 2+ s 2 5 –6 Ve: 6 – 8 Fu: 8–10, 0 mi Abd. IV 2 4+s 8–10 Ve: 6 + 1 Vl: 5–6 Abd. V 11 +s Ag: 5–7 Vl: 5–6 Abd. VI 7 Ve: 12–13 An: 2–3 mi Cryptopygy present ( Fig. 39 ). Chaetotaxy of legs as in B. mahunkai and in Tab. 4. M chaeta present. Claw without tooth. Posterior surface of each trochanter with one modified chaeta in same position as in B. mahunkai . Femur I–III with one modified chaeta both on anterior and on posterior side in same position as in B. mahunkai .

Variability. See: Tabs 3–4 and in literature summarised in Tab. 5 .

Ecology. Two of the specimens (collpr-441, collpr-443) were collected in the thick layer of leaf litter of an oak forest and in that of a spruce forest respectively, while the other four specimens were found in decaying wood within ruderal vegetation (altogether in a range of 520–1377 m above sea level). Cassagnau (1967) reported the species from spruce forests, aleppo pine forests and from a cave too (50–1000 m a.s.l.), while Traser & Kontschán (2004) found their specimen in the leaf litter of a beech forest (1300 m a.s.l.). According to these data B. matsakisi seems to be a rather euryoecious in terms of habitat requirements and it is expectable to be much more widespread in the Balkan Peninsula than it is known presently.

Taxonomical remarks. B. digitata and B. matsakisi were originally described by Cassagnau (1967). Indeed, two papers containing the original descriptions were published ( Cassagnau 1967, 1968), but Cassagnau (1967) was published earlier and should be taken as providing the first valid descriptions of the species. In some cases the year of the original descriptions has been erroneously reported as 1968 ( Traser & Kontschán 2004, Deharveng 2007), referring to Cassagnau (1968) that also provided illustrations additionally to the descriptions, but was published later.

Traser & Kontschán (2004) found one specimen of B. matsakisi in Albania near to the type locality of B. proxima , a species differing only in size (1.5– 2 mm) and in the number of chaetae on tubercles L on abd. I–IV and (De+Dl) on abd. IV ( Tab. 5 ). Actually, the Albanian B. matsakisi specimen shows some characters intermediate to B. proxima . The difference of these characters was interpreted by Traser and Kontschán (2004) as „being related to the size and age” which is unusal for Neanuridae . Variability of the chaetae’s numbers on the abdominal tubercles was observable in our B. matsakisi specimens as well, even in specimens collected in the same locality. This variability also might implicate the consideration of B. proxima as a junior synonym of B. matsakisi . However, the Albanian as well as the Greek specimens have 5 chaetae on tubercle (De+Dl) of abd. IV, which seems to be constant and characteristical for B. matsakisi . As there was no intraspecific variability in this number and as it is lower in B. matsakisi than in the smaller B. proxima it can be used to differentiate the two species. More detailed investigation on the latter species may serve further features for separation of these two taxa.

Figures

FIGURE 1. Locus typicus of Bilobella mahunkai sp. nov. (black star) and its position regarding the type localities of the North Albanian Bilobella species. (white dot: Bilobella proxima, black square: Bilobella subaurantiaca, white square: Bilobella albanica, black triangle: Bilobella zekoi, white triangle: Bilobella matsakisi).

FIGURE 2. Bilobella mahunkai sp. nov.: habitus and colour of living specimens.

FIGURES 39 – 44. Bilobella matsakisi Cassagnau, 1967: 39, habitus and dorsal chaetotaxy; 40, mandible and maxilla; 41, head of mandible; 42, apex of maxilla; 43, chaetotaxy of labrum; 44, dorsal chaetotaxy of ant. III – IV.

FIGURES 3 – 6. Bilobella mahunkai sp. nov.: 3, habitus and dorsal chaetotaxy; 4, head chaetotaxy with aberrant single G chaeta in Af (frontal view); 5, ventral chaetotaxy of head; 6, chaetotaxy of labium (ventral view).

FIGURES 7 – 15. Bilobella mahunkai sp. nov.: 7, chaetotaxy of labrum. 8, mandible and maxilla; 9, head of mandible; 10, dorsal chaetotaxy of ant. I – II; 11, ventral chaetotaxy of ant. I – II; 12, apical vesicle of ant. IV; 13, antennal organ of ant. III (medial view); 14, dorsal chaetotaxy of ant. III – IV; 15, ventral chaetotaxy of ant. III – IV.

Tables

TABLE 3. Cephalic chaetotaxy of Bilobella matsakisi Cassagnau, 1967.

Af	6	Ml Mc	B C, E
Oc	2	Ml	Ocm
(Di+De)	4	Mc Ml	Oca Di1, De1

TABLE 5. Infraspecific variability of some characters in Bilobella matsakisi Cassagnau, 1967 found in literature and in present study.

	B. proxima (orig. B. matsakisi descr.) (orig. descr.)	B. matsakisi (Traser B. matsakisi (present & Kontschán 2004) study)
size (mm)	1.5–2 up to 4	2.7 2.6–3.3
abd. I: L	3 6–7	3 3
abd. II: L	4 7–9	6 4–5
abd. III: L	4 7–9	6 5–6
abd. IV: L	9–11 10–11	8 8–10
abd. IV: (De+Dl)	6 5	5 5
abd. V: (Di+De+Dl+L)	10–12 11	11 12