Paralobella kuchierabu, Kasai & Hayasaka & Sawahata, 2022

Kasai, Hiro, Hayasaka, Daisuke & Sawahata, Takuo, 2022, First report of the genera Paralobella and Blasconura (Collembola: Neanuridae Neanurinae) from Japan with the description of three new species, Zootaxa 5168 (3), pp. 332-349 : 333-337

Paralobella kuchierabu sp. nov.

[Japanese name: kuchierabu-yokoge-ibotobimushi]

Figures 1–11 , Table 1

Type material. Holotype: female, Japan, Kagoshima, Kuchinoerabu-jima (alt. 255 m, 30°27'25"N, 130°13'52"E), 4-XII-2021, Hiro Kasai leg. ( NMNS, NSMT-Ap 591) . Paratypes: 2 females ( NMNS, NSMT-Ap 592, NSMT-Ap 594), male ( NMNS, NSMT-Ap 593) and juvenile ( NMNS, NSMT-Ap 595), same data as holotype .

Diagnosis. 3+3 black eyes on head. Body color yellow living and white in alcohol. Body elongated and flattened, dorsal tubercles weakly developed. Labrum chaetotaxy as 0/ 2, 2. Mandible with three teeth. maxilla consists of 2 styliform lamellae, one pointed and smooth and one with two distal microteeth. Cephalic chaeta O present. Cephalic tubercle Dl separate from L and So. Tubercle Di of Th. I with 1 chaeta. Tubercle De of Th. II–III with 5 (4+s) chaetae. Tubercle De on Abd. V separated with only 1 sensory chaeta. Furcular remnant with 5–6 chaetae. Ventral chaetae Ve in Abd. VI with 14 mesochaetae and 3 microchaetae.

Description. Body length: 2.84–3.73 mm in adults. Color: Yellow alive, white in alcohol. Eyes: 3+3, pigmented. Body elongated and flattened, and head and tergite tubercles weakly developed ( Fig. 1 ). Types of dorsal ordinary chaetae: macrochaetae Ml relatively long and thickened, arc-like or straight, narrowly sheathed, feebly serrated, apically rounded ( Fig. 4 ); some lateral chaetae weakly acuminate, and slightly sheathed. Macrochaetae Mc and Mcc morphologically similar to long macrochaetae, but much shorter. Mesochaetae and microchaetae similar to ventral chaetae: thin, smooth, and pointed. S–chaetae of tergites thin, smooth.

Antennal morphology and chaetotaxy ( Figs 2, 3 and Table 1c ). Antenna 4-segmented. Ratio of antennal segments as I: II: III + IV = 1: 1: 1.5. Ant. I and II with 7 and 11 chaetae respectively, without serrated chaetae. Ant. III dorsally fused to Ant. IV. AOIII consists of 2 short rods, ventral ms and 2 longer sensory chaetae (sgd and sgv), with sgd positioned at a location higher than the 2 rods ( Fig. 2 ). Ant. IV dorsally with 13 mou-sensilla (immature with 12) ( Fig. 2 ). Ant. IV laterally with 2 iv and 7 brs (immature with 6). ( Figs 2–3 ). Apical bulb distinct, trilobed.

Mouthparts. Labrum chaetotaxy 0/2, 2 ( Fig. 7 ). Labium with 4 basal, 3 distal, and 4 lateral chaetae, papillae x absent ( Fig. 9 ). Mandible with 2 apical teeth and 1 basal tooth ( Fig. 5 ). Maxilla styliform, maxillary head consisting of 2 lamellae, one pointed and smooth and one with two distal microteeth ( Fig. 6 ).

Cephalic tubercles and chaetotaxy ( Figs 1 , 8 and Table 1a, 1b ). Dorsal central area with 3 well-differentiated tubercles (2 Oc and Fr), tubercles Cl and An weakly differentiated. Dorsal posterior area with 4 separate tubercles (2 Di and 2 De); 2 tubercles Di close to each other ( Fig. 1 ). Dorso-lateral area with 6 differentiated tubercles (2 Dl, 2 L, 2 So), tubercle L much lower ( Fig. 8 ). Chaetal group So with 9 chaetae, 3–6 chaetae out of tubercles. On the ventral side of head, group Vi with 6+6 chaetae, and groups Vea, Vem, and Vep with 4, 3, and 4 chaetae respectively ( Fig. 8 ).

Body tubercles and chaetotaxy ( Figs 1 , 10 and Table 1d ). Tubercles L on Abd. I–IV, each with 1 additional sensory chaeta in addition to ordinary chaetae. Abd. IV dorsally with 4+4 tubercles (Di, De, Dl, L), tubercle Di much lower (sometimes absent), tubercles De, Dl, and L on Abd. IV close to each other and situated on the lateral side. Abd. V dorsally with 3+3 tubercles (Di, De, Dl), tubercle De separated with only 1 sensory chaeta, and tubercle L ventrally situated. Abd. VI with 1+1 tubercles, no cryptopygy. Ventral chaetotaxy of Abd. II–VI given on Fig. 10 . VT with 4+4 chaetae. Furcular remnant with 5–6 rather long chaetae. Genital plate with 17–18 and 38 chaetae in females and males respectively.

Legs ( Fig. 11 and Table 1d ). Tibiotarsi I, II and III with 19, 19, and 18 chaetae respectively. Unguis ventrally with 1 inner tooth, basal granules and medial transverse striae. Tenent hair absent ( Fig. 11 ).

c) Chaetotaxy of antennae.

Etymology. After Japanese name: kuchierabu-yokoge-ibotobimushi.

Ecology. This new species was discovered amid fallen trees and branches decaying with brown rot in evergreen broad-leaved forests dominated by Castanopsis sieboldii subsp. sieboldii .

Remarks. Paralobella is widely distributed in East and South-East Asia and has been reported in Thailand, Malaysia, the Philippines, China, and Indonesia ( Jiang et al. 2018). Morphologically Paralobella kuchierabu sp. nov., is most similar to P. tianmuna Jiang, Wang & Xia, 2018 , resembling this species in having cephalic chaeta O present, tubercle De of Th. II–III with 5 (4+s) chaetae, tubercle Di of Th. I with 1 chaeta, tubercles De and Dl of Abd. V separated, and tubercle Di of Th. II–III with 3 chaetae. However, this new species is clearly distinguishable from P. tianmuna by its body color (in P. kuchierabu sp. nov. yellow, in tianmuna red), number of mandibular teeth (in P. kuchierabu sp. nov. 3, in tianmuna 7), and number of chaetae on tubercle L of Abd. II–III (in P. kuchierabu sp. nov. 5, in tianmuna 7). This new species is also similar to P. perfusa ( Denis, 1934) . However, they differ in the body color (in P. kuchierabu sp. nov. yellow, in perfusa red), number of chaetae on tubercle Di of Th. II–III (in P. kuchierabu sp. nov. 3, in perfusa 2), and the number of chaetae on tubercle L of Abd. II–III (in P. kuchierabu sp. nov. 5, in perfusa 4). The key for all species of the genus is as follows:

Figures

FIGURES 1–6. Paralobella kuchierabu sp. nov. 1, dorsal tubercles and chaetotaxy (left side of tubercle Dl on Th. III abnormal); 2, dorsal chaetotaxy of Ant. III–IV; 3, ventral chaetotaxy of Ant. III–IV; 4, chaeta Di1 of abd. V; 5, mandible; 6, maxilla.

FIGURES 7–11. Paralobella kuchierabu sp. nov. 7, labrum; 8, chaetotaxy of lateral area and ventral side on head; 9, labium; 10, ventral side of abdomen; 11, chaetotaxy of tibiotarsus III and unguis.

Tables

TABLE 1. Chaetotaxy of Paralobella kuchierabu sp. nov.

a) Cephalic chaetotaxy––dorsal side.
Chaetal group	Tubercle	Number of chaetae	Types of chaetae	Names of chaetae
Cl	+	4	Mc	F
			me	G
An	+	2	Ml	B
			Mc	E
	-	2	me or mi	C, D
Fr	+	2	Mc	A
			Mcc	O
Oc	+	3	Ml	Ocm
			me or mi	Oca, Ocp
Di	+	1	Mc	Di1
	-	1	mi	Di2
De	+	1	Ml	De1
	-	1	mi	De2
Dl	+	4	Mc+me+2mi	uncertain
L	+	2	Mc+me	uncertain
So	+	9 (3–6 chaetae free)	2Ml+7me	uncertain
b) Cephalic chaetotaxy––ventral side.
Group			Number of chaetae
Vi			6
Vea			4
Vem			3
Vep			4
labium			11, 0x