Folsomides mediterraneus, Arbea, Javier I. & Jordana, Rafael, 2002

Arbea, Javier I. & Jordana, Rafael, 2002, The genus Folsomides Stach of the Ibero­balearic fauna, with description of a new species (Collembola, Isotomidae), Zootaxa 55, pp. 1-8 : 2-6

Folsomides mediterraneus n. sp.

( Figs. 1­9 )

Size: 0.7­0.9 mm males, 0.8­1.0 mm females. Colour: blue greyish; pigment more concentrated in eye fields. Body long and slender ( Fig. 7 ). Dorsal mesochaetae smooth and pointed. Subaxial SA macrochaeta on abdominal tergite IV 0.4 times tergite length ( Fig. 1 ).

Antennae shorter than cephalic diagonal. Antennal segment IV with some 21 dorsal cylindrical sensilla, a dorso­external microsensillum and a subapical pit organ. Sensory organ of antennal segment III with a pair of small and rounded microsensilla and two short sensilla, one on each side. Another sensillum found in a ventrolateral location. Antennal segment III with 22 normal chaetae. Antennal segment II with a small subcylindrical ventral sensillum and 18 normal chaetae, and some of the basal ones short and fine. First antennal segment with two subcylindrical ventral sensilla and 12 normal chaetae; one of the basal chaetae smaller than the others ( Fig. 3 ).

Five corneola on each side of head. Postantennal organ long and narrow, 2.5 times corneolae diameter and width of a corneola, with two posterior chaetae ( Figs. 4 & 8 ). Clypeolabral chaetae formula: 2/5,5,4. Maxillary palp bifurcate with three sublobal chaetae.

Dorsal chaetotaxy represented in Figure 1 . Axial chaetotaxy of thoracic tergites II­III and abdominal tergites I­V have 5,3/3,3,3,4,2 pairs of mesochaetae respectively. Macrochaetotaxy: 1,1/0(1),1,1,3,3; type 3 of Fjellberg (1993), but lateral macrochaeta (L) of abdominal tergite I similar in length to normal chaetae. Microsensillar chaetotaxy: 1,1/ 0,0,0. Sensilla short, smooth and blunt ( Fig. 9 ), half as long as mesochaetae. Two lateral sensilla on abdominal tergite V subequal, slightly smaller than the two medial sensilla.

Tibiotarsi of legs I, II and III with 20, 20 and 22 pointed chaetae respectively. Chaetae A1­A7, B1­B7, C1­C7 and x present on tibiotarsus of leg III. Tibiotarsi of legs I and II with single chaeta B4/5. B5 and x chaetae of legs III in males rod­like modified ( Fig. 5 ). Claw with no teeth on inner edge. Empodial appendage sharp; its length less than half internal edge of claw.

Ventral abdominal chaetotaxy represented in Figure 2 . Ventral tube with 3+3 distal chaetae and 1+1 basal ones. The retinacle with 3+3 teeth and one chaeta on corpus. Subcoxa of furca with six chaetae on anterior side and five on posterior side.

Furca well developed. Manubrium usually with 9+9 dorsal and no ventral chaetae. Dens with five dorsal chaetae and one chaeta in ventro­apical location ( Fig. 6 ). The mucro with two teeth, with a small lateral lamella from base to subapical tooth.

Types Locality: Caparroso, Bardenas (Navarra), Spain. Mediterranean shrub of Rosmarineto­Linetum of the association of Rosmarino­Ericion. Soil on gypsy rock (torriorthent typical), altitude 300 m, UTM: 30TXM1184, date: 20­VII­1982. leg. Jordana.

which are present in Europe, north Africa and the Canary Islands.

Species ms Mc Dens Mucro Retinacle maxillary Distribution (1) (2) (3) (4) (5) Palp.

F. petiti (Delamare, 1951) 10/000 11/11133 2/0 2 3/0 bifurcate Iberian Peninsula,

sensu Fjellberg, 1993 Canary Islands, France

F. pocosensillatus Fjellberg, 1993 10/000 11/11133 2/1 2 3/1 simple Iberian Peninsula,

Canary Islands (1): Number of microsensillae from Thor. II to Abd. III. (2): Macrochaetae from Thor. II to Abd. V. (3): Dens:

Number of dorsal chaetae/ventro­apical. (4): Mucro: 1 or 2 (with 1 or 2 tooth). (5): Retinacle: Number of

tooth/chaetae.

Holotype female on slide CA0144­05. Number of paratype specimens in the slides: 5 in CA0144­06, 1 in CA0144­07, 1 in CA0144­09, 7 in CA0144­ 10, 5 in CA0144­ 11, 2 in CA0144­ 12, 7 in CA0144­ 13, 3 in CA0145­04, 1 in CA0145­05 and 196 in ethyl alcohol. All specimens are deposited in the Zoology Museum at the University of Navarra.

Other specimens: Specimens from the same locality and biotope: 234 from 27­X­1982 (samples CA0276 & CA0279). 27 from 1­III­1983 (samples CA0539 & CA0542). Specimens from the same locality and biotope but occurring in Pinus halepensis litter: 1 from 20­VII­1982 (sample CA0147), 3 from 27­X­1982 (sample CA0282). All these specimens were cited as Folsomides angularis ( Jordana et. al., 1987).

Madrid: Aranjuez, grass on soil of gypsy Serosem, HA, 21­III­1954, leg. W. Steiner (sample T72a). Vallecas, UTM: 30TVK4770, soil of gypsy Serosem, HA, 4­IV­1954, leg. W. Steiner (sample T73), deposited in the Museo de Ciencias Naturales in Madrid, labelled by Steiner as Folsomides n. sp.

Zaragoza: Retuerta de Pina, Pina de Ebro, UTM: 30TYL75, Mediterranean shrub of the Ononidetum tridentatae association, on moss ( Pleurochaete squarrosa ) and gypsy soil, numerous specimens of different dates between 1987­1992, leg. J. Blasco Zumeta. Deposited in the private collection of J.I. Arbea.

Discussion: Following Fjellberg (1993), Folsomides mediterraneus n. sp. belongs to the species group of Folsomides angularis (Axelson, 1905) as it has 5+5 corneolae and dens with mucro. The new species is close to F. t e r r u s Fjellberg, 1993 which has identical microsensillar chaetotaxy (11/000), but it is very different according to some other characteristics ( Table 1). According to its dental chaetotaxy (5/1) it is close to F. portucalensis Gama, 1961 , but it differs in the microsensillar distribution.

The main diagnostic characteristics are summarised in Table 1.

Biology: Folsomides mediterraneus n. sp, lives in a very dry area of Spain characterised by gypsy soils, and typical mediterranean shrub.

Derivatio nominis: Its name refers to the broad distribution of the specimen in the Mediterranean area of Spain.

Figures

FIGURES 1 ­ 6. Folsomides mediterraneus n. sp. 1. Dorsal chaetotaxy. 2. Ventral chaetotaxy. 3. Antenna. 4. Postantennal organ and eye. 5. Tibiotarsus and claw of leg III of a male. 6. Furcula.

FIGURES 7 ­ 9. Folsomides mediterraneus n. sp. Scanning electron microscope (SEM). 7. Habitus and leg I. 8. Postantennal organ and two eyes, with details of the perforated plate of the PAO. Thoracic tergite I from lateral view showing two sensilla and a spine­like microsensillum.