Isotomiella Bagnall 1939 (Collembola Isotomidae) of Sumatra (Indonesia)

Tropical Zoology ISSN: 0394-6975 (Print) 1970-9528 (Online) Journal homepage: http://www.tandfonline.com/loi/ttzo20 Isotomiella Bagnall 1939 (Collembola Isotomidae) of Sumatra (Indonesia) L. Deharveng & Y. R. Suhardjono To cite this article: L. Deharveng & Y. R. Suhardjono (1994) Isotomiella Bagnall 1939 (Collembola Isotomidae) of Sumatra (Indonesia), Tropical Zoology, 7:2, 309-323, DOI: 10.1080/03946975.1994.10539261 To link to this article: http://dx.doi.org/10.1080/03946975.1994.10539261 Published online: 01 Aug 2012. Submit your article to this journal Article views: 89 View related articles Citing articles: 2 View citing articles Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalinformation?journalcode=ttzo20 Download by: [46.3.192.235] Date: 20 November 2017, At: 06:02

Tropical Zoology 7: 309-323, 1994 lsotomiella Bagnall1939 (Collembola Isotomidae) of Sumatra (Indonesia) L. DEHARVENG 1 and Y.R. SuHARDJONO 2 1 UPR 9014 du CNRS, Laboratoire de Zoologie, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex, France 2 Museum Zoologicum Bogoriense, Bogar, Java, Indonesia Received 9 March 1993, accepted 15 October 1993 The genus Isotomiella is recorded for the first time on Sumatra island. Nine species have been collected, of which seven are new to science and described in this paper: Isotomiella annae n. sp., I. barisan n. sp., I. deforestai n. sp., I. dubia n. sp., I. thiollayi n. sp., I. cribrata n. sp. and I. michonae n. sp. The remaining two species, recently described from South America, are probably pantropical forms: I. symetrimucronata Najt & Thibaud 1987 ( = prussianae Oliveira & Deharveng 1990, n. syn.) and I. nummulifer Deharveng & Oliveira 1990. KEY WORDS: Collembola, Isotomidae, Isotomiella, Thailand, taxonomy. Introduction Studied sites and methods Sumatran species of Isotomiella List of species Key to Sumatran species Remarks about some taxonomic characters Descriptions Isotomiella annae n. sp. Isotomiella barisan n. sp. Isotomiella deforestai n. sp. Isotomiella dubia n. sp. Isotomiella thiollayi n. sp. Isotomiella cribrata n. sp. Isotomiella michonae n. sp. Acknowledgements References 310 310 310 310 311 312 313 313 315 316 318 319 320 322 323 323

310 L. Deharveng and Y.R. Suhardjono INTRODUCTION The genus Isotomiella was established by BAGNALL (1939) for the widespread temperate species Isotoma minor Schaeffer 1896, described from Germany. The number of species in the genus increased slowly until1989. At this date, 18 species or subspecies were assigned to Isotomiella. Eight were considered as synonyms of I. minor or of I. paraminor Gisin 1942, and eight were closely related to these two species. The remaining species were two strange African forms of unknown affinities (I. bidentata Delamare 1950 and I. delamarei Barra 1968). In a survey of Amazonian soil Collembola collected by E. Oliveira, our attention was drawn to some minute, white Isotomidae with short furca, which were found to be Isotomiella species, recalling the African forms described by DELAMARE DEBOUTTE VILLE (1950) and BARRA (1968). This finding led us to re-examine our Amazonian Isotomiella. It contained no less than 13 species, all new to science, which were described in two recent papers (DEHARVENG & OuvEIRA 1990, OLIVEIRA & DEHAR VENG 1990). We began to suspect that Isotomiella might be much more diversified than originally thought. We had collected in recent years a large material of soil Collembola in South-East Asia in which, as usual for tropical fauna, Isotomiella was the dominant genus of Collembola. A re-examination of this material, formerly identified as Isotomiella minor, the only species cited in the area (YAYUK 1989), showed that it contained a diversity of species nearly as high as the Amazonian samples. The present paper deals with species of the genus collected in Sumatra island (Indonesia) during the project «Agroforestry practices and conservation of biological diversity in tropical rainforests. Indonesian cases» (1991-1992), which aimed at evaluating biodiversity patterns in the primary forests versus the agroforests of Sumatra. STUDIED SITES AND METHODS Three main sites were sampled in Sumatra (Fig. 1):..(1) May 1991: Krui area in Lampung province, where agroforests are dominated by Shorea Javanzca K. & L. (kebun damar: MicHoN & BoMPARD 1987);. (2) June 1991: Muarabungo area injambi province, where Hevea agroforests (kebun karet) are widespread; (?)July 1992: Maninjau lake area in Sumatra Barat province, where Durio zibethinus Murr. and Cznnamo'!'um bu~anii Bl.. are the main trees in agroforests (MICHON et al. 1986).. Both primary ramforest soils and agroforest soils were sampled at each site. The agroforests studied a~e structured mu.ch as true forests, with a variety of large trees grown for fruits (durian), wood (~mnamon) or resms (damar, Hevea), with usually a well diversified understorey.. Dif~erent ~ample _methods we.re used: pitfall trapping, direct collecting under stones and logs, soil washing, soil and litter extraction. The latter was performed in field laboratories set up in the villages, using the field Berlese-Tullgren apparatus. SUMATRAN SPECIES OF ISOTOMIELLA List of species (1) symetrimucronata Najt & Thibaud 1987 (= prussianae Oliveira & Deharveng 1990, n. syn.) (Ecuador, Brasil, Seychelles, Indonesia); we examined the type material

Isotomiella from Sumatra 311 200 km Fig. 1. -The study sites on Sumatra island: 1, Krui; 2, Muarabungo; 3, Maninjau. of I. symetrimucronata and found it identical in all respects with prussianae; this species is dominant in soils and litters of the three studied sites; (2) nummulifer Deharveng & Oliveira 1990 (Brasil, Seychelles, Indonesia); abundant in soils and litters of the three studied sites; (3) annae n. sp. (Sumatra); (4) barisan n. sp. (Sumatra); (5) deforestai n. sp. (Sumatra); (6) dubia n. sp. (Sumatra); (7) thiollayi n. sp. (Sumatra); (8) cribrata n. sp. (Sumatra); (9) michonae n. sp. (Sumatra). Key to Sumatran species 1 Mucro falciform annae n. sp. Mucro bidentate or tritentate 2 Mucro bidentate nummulifer Deharveng & Oliveira 1990 Mucro tridentate 3 Dens with 5 dorsal chaetae Dens with 6 dorsal chaetae 4 Several ciliated chaetae on ant. I barisan n. sp. No ciliated chaetae on ant. I deforestai n. sp. 2 3 4 5

312 L. Deharveng and Y.R. Suhardjono 5 6 7 8 Several ciliated chaetae on ant. I No ciliated chaetae on ant. I Manubrium with 5 + 5 ventro-distal, and no unpaired ventra-proximal chaetae.... cribrata n. sp. Manubrium with 5 + 5 ventro-distal, and 2-3 unpaired ventro-proximal chaetae....... michonae n. sp. A ventro-lateral area devoid of chaetae on abd. II of adult.......... symetrimucronata Najt & Thibaud 1987 Ventro-lateral area with chaetae on abd. II of adult...... Subcoxae I with 1, 3, 2-(3) chaetae thiollayi n. sp. Subcoxae I with 1, 1, 2 chaetae dubia n. sp. 6 7 8 REMARKS ABOUT SOME TAXONOMIC CHARACTERS Taxonomic characters of Isotomiella have been reviewed by DEHARVENG & OLIVEIRA (1990) and OLIVEIRA & DEHARVENG (1990). We present here additional remarks about a few critical or interesting points. Supplementary S-chaetae on ant. IV. Three types of S-chaetae can be recognized on ant. IV of Isotomiella: (1) six large, thickened chaetae S1 to S6, peculiar to the genus, with interspecific differences in their relative length and thickness; the arrangement of these chaetae is stable, yet slight differences may exist between species (Figs 3, 12, 16); (2) some subcylindrical S-chaetae, less thickened than the former, with rather high intra-specific variability in number; one of those chaetae is noticeably enlarged in the species of the delamarei group (I. annae n. sp., I. nummulifer Deharveng & Oliveira 1990, I. spinifer Deharveng & Oliveira 1990, I. quadriseta Deharveng & Oliveira 1990, I. barrai Deharveng & Oliveira 1990); (3) a large number of blunt S-chaetae, often hardly distinguishable from ordinary chaetae, and not used for the taxonomy of the genus. S-chaetotaxy of tergites. Two patterns of S-chaetae are observed in Sumatran Isotomiella. The minor-group pattern, as defined by OLIVEIRA & DEHARVENG (1990), is found in most species, with 3, 2 I 0, 0, 1, 3, 5 S-chaetae on each half-tergite; the morphology of Spl of abd. V shows interesting interspecific variations in length and width, whereas other S-chaetae are quite stable. The second pattern is restricted to I. nummulifer and I. annae n. sp.; S-chaetae are present on abd. I-II, but their number is reduced on IV-V [formula: 3, 2 I 1, 1, (1-2), 1, 2]; similar patterns are described in several Amazonian species by DEHARVENG & OLIVEIRA (1990). Chaeta SL2 of th. II differs from other S-chaetae in its usually acute apex, making it difficult to distinguish from ordinary chaetae; it has however a peculiar morphology, being more or less flame-like, with a socket considerably less differentiated than other S-chaetae. Distal tenent hairs of tibiotarsus III. These tenent hairs are either thickened, or thin. In this last case however, a careful observation shows that the two tenent hairs differ slightly in length and thickness, the dorsal one being thinner and longer than the dorso-internal one. This character was found to be very stable in the specimens examined, and is therefore reported in descriptions.

Isotomiella from Sumatra 313 DESCRIPTIONS Symbols and abbreviations used in the descriptions follow DEHARVENG & OLI VEIRA (1990). Additional abbreviations used in ratios: ant, antenna length; L, body length; M, length of the macrochaeta anterior to Spl on abd. V; S, long S-chaeta of ant. I; s, short S-chaeta of ant. I. Type material is deposited in the collections of the Laboratoire d'ecologie des Invertebres Terrestres, Universite P. Sabatier, Toulouse (France) (LEITT) and of the Museum Zoologicum Bogoriense (Boger, Indonesia) (MZB). Isotomiella annae n. sp. (Figs 2-5) Type material. Holotype female and 2 paratypes: «Lampung prov., Krui, Pahmungan, Kebun damar, alt. 70 m, soil, 23.5.1991, Deharveng leg.» (SUM 4, 16, 26); 1 paratype as above, except «25.5.91» (SUM 50). Holotype and 2 paratypes in LEITT; 1 paratype in MZB. Description. Length: 0.40-0.55 mm. Habitus like Isotomiella minor with rather short furca. Large craters on tergites of abd. V-VI, as in I. nummulifer. No secondary granules on tergites or ant. IV. Integument channels and pseudopora not seen. Head. Anterolateral chaetae of labrum thickened but not spine-like. Maxillary outer lobe with bifurcate palp, without ciliated chaetae, and with 3 sublobal hairs. Antennae short (L:ant = 4.3). Chaetae S1-S6 of ant. IV subequal, ovoid. Supplementary S-chaetae of ant. IV subcylindrical, subequal, thin, most hardly distinct from ordinary chaetae (3 internal and 3 external) except 1 external shorter and thicker. Ant. I with 13-14 smooth ordinary chaetae, 2 basal microchaetae and 2 unequal S chaetae (S:s = 2-2.2). All chaetae of head smooth. Tergites. Axial chaetotaxy from th. II to abd. IV: 16-18, 12 I 6, 6, 6, 6. Macrochaetae indistinctly or slightly ciliated, erect, rather short, 1, 1 I 3, 3, 3, 4 by half-tergite from th. II to abd. IV. Mdl:ML = 0.6-0. 7 on abd. I. Mesochaetae not or very slightly ciliated (only a few cilia) on tergites. No ventro-lateral area devoid of chaetae on abd. II. On abd. VI, p1 is a smooth macrochaeta, ao a very short, smooth mesochaeta, mo a smooth macrochaeta, po a smooth mesochaeta. Formula of S chaetae: 3, 2 I 1, 1, 1, 1, 2 by half somite from th. II to abd. V; SLl on th. II and th. III, Spl on abd. II and abd. IV, and Sv on abd. III and abd. V are very longs-chaetae; SL3 on th. II and Spl on abd. V are medium-size S-chaetae; SL2 on th. II and th. III, and Spl on abd. I are short S-chaetae. SL3 of th. II has migrated towards the subcoxae like in I. nummulifer. Spl of abd. V rather small and moderately thick (Spl:GIII = 1.1-1.25; M:Spl = 2.6-3.1). Appendages. Two spine-like tenent hairs on tibiotarsus III and 1-2 on tibiotarsus II. Femoral tenent hair not or indistinctly ciliated on Felli. No spine-like chaetae on femora, trochanter or coxae. Subcoxae 1 of legs I, II, III with 1, 2, 3 chaetae. Claw short, but rather slender distally. Ventral tube with 4 + 4 distal, 3 + 3 anterior and 2 + 2 posterior chaetae. Tenaculum with 4 + 4 teeth and 1 chaeta. Subcoxae anterior with 8 chaetae (of which at least 2 ciliated), posterior with 7 chaetae (of which 5-6 ciliated). Manubrium with 1 + 1 ventre-distal, 11 + 11 dorsal and 1-2 lateral chaetae. Dorsal chaetae on dens and manubrium smooth and thin, ventral chaetae thicker and smooth. Dens short, with 15 ventral and 3 dorsal chaetae. Distal chaeta of dens 2 X the antedistal one. Mucro rather large, falciform. Basal hooks of dens normal.

314 L. Deharveng and Y.R. Suhardjono Figs 2-8. -Figs 2-5, Isotomiella annae n_ sp.; Fig. 2, habitus, with tergite S-chaetae; Fig. 3, right ant. IV with thickened S-chaetae (circles: sockets of blunt chaetae and ordinary chaetae); Fig. 4, abd. V-VI, lateral view; Fig. 5, manubrium and mucrodens ventrally (left), dens basis dorsally (right). Figs 6-8, I. barisan n. sp.; Fig. 6, manubrium and mucrodens ventrally (left), dens basis dorsally (right); Fig. 7, right ant. IV with thickened S-chaetae; Fig. 8, chaetotaxy around Spl of abd. V. (Scales, Fig. 2: 100 11m; Figs 3-8: 20 11m).

Isotomiella from Sumatra 315 Derivatio nominis. We are pleased to dedicate this species to Anne Bedos who assisted us patiently and efficiently in the field. Discussion. I. annae n. sp. is the rarest species in our material. It shows a remarkable set of regressive chaetotaxic characters. Its pattern of S-chaetae on tergites is similar to that of I. spinifer Deharveng & Oliveira 1990 from Amazonia or of I. nummulifer: absence of Sa, Spi and Spe on abd. V, Spl shorter than Sv on abd. V, and SL3 of th. II displaced towards subcoxae, but the chaeta Spl of abd. III was not seen in the new species. The falcate mucro of the new species is unique in Isotomiella, yet a closely related genus (Denisia Folsom 1932 from Hawai) was described with the same characteristic feature. However, LAWRENCE (1969) showed that Denisia resulted from a mixed description of Folsomina Denis 19 31 for the posterior part (including the falcate mucro) and Isotomiella for the anterior part of the body. Isotomiells biu'issn n. sp. (Figs 6-8) Type material. Holotype female: <<Jambi prov., Muarabungo, Rantaupandan, alt. 150 m, primary forest, soil, 12.6.1991, Deharveng & Bedos leg.» (SUM 323); 12 paratypes as above (SUM 315, 319, 325, 335, 339, 349, 355); 4 paratypes as above, except «Kebun karet, 9.6.91» (SUM 228, 230, 250, 252). Holotype and 10 paratypes in the collection of the LEITT; 6 paratypes in the collection of the MZB. Other material. «Lampung prov., Krui, Liwa, primary forest, alt. 800 m, soil, 29.5.91, Deharveng leg.», 3 specimens (SUM 135, 159); as above except «litter», 1 specimen (SUM 172). Description. Length: 0.8-0.9 mm. Habitus like Isotomiella minor. No craters or secondary granules distinct on body integument. No secondary granules on ant. IV. Integument channels present ventrally and laterally from head to abd. II, and on the posterior part of th. III to abd. II. Pseudopora not observed. Head. Anterolateral chaetae of labrum thickened but not spine-like. Maxillary outer lobe with bifurcate palp, without ciliated chaetae, and with 4 sublobal hairs. Antennae long (L:ant = 3.2-3.5). Chaetae S1-S6 of ant. IV subequal, ovoid-elongate. Supplementary S-chaetae of ant. IV subcylindrical, subequal, 3 internal and 5-7 external. Ant. I with 17-18 ordinary chaetae (of which 2-4 external and 2-4 internal ciliated), 2 basal microchaetae and 2 unequal S-chaetae (S:s = 1.5). All chaetae of head smooth. Tergites. Axial chaetotaxy from th. II to abd. IV: 20-24, 14-16 I 6, 6, 6, 6. Macrochaetae strongly ciliated, erect, long, 1, 1 I 3, 3, 3, 4-5 by half-tergite from th. II to abd. IV. Mdl:Md = 0. 75, Mdl:ML = 0.65 on abd. I. Both ciliated and smooth mesochaetae present on tergites: th. II-III: 3-4 lateral ciliated, others smooth; abd. I: all smooth; abd. II: all posterior, most anterior and a few lateral ciliated, other smooth; abd. III-VI: most ciliated, some smooth. No ventro-lateral area devoid of chaetae on abd. II. On abd. VI, p1 is a ciliated macrochaeta, ao a smooth mesochaeta, mo a ciliated macrochaeta, po a ciliated mesochaeta. Formula of S-chaetae of the minor-type: 3, 2 I 0, 0, 1, 3, 5 by half somite from th. II to abd. V. SL3 of th. II has not migrated towards the subcoxae. Spl of abd V thick and rather short (Spl:GIII = 1.2-1.5; M:Spl = 3-3.5); Sa, Spe and Spi of abd. V more than twice as long as S chaetae of abd. IV.

316 L. Deharveng and Y.R. Suhardjono Appendages. No spine-like tenent hairs on tibiotarsus III. Femoral tenent hair strongly ciliated on Felli. No spine-like chaetae on femora, trochanter or coxae. Subcoxae 1 of legs I, II, III with 1, 3, 3 chaetae of which 1, 2-3, 2-3 ciliated. Claw rather slender. Ventral tube with 4 + 4 distal, 3 + 3 anterior and 2 + 2 posterior chaetae. Tenaculum with 4 + 4 teeth and 1 chaeta. Subcoxae anterior with 18-20 chaetae (of which 9-10 ciliated), posterior with 8 chaetae (of which 6-7 ciliated). Manubrium with 5 + 5 ventro-distal, 3-4 unpaired ventro-proximal and 3-4 lateral chaetae. Dorsal chaetae on dens and manubrium smooth and thin, ventral chaetae thicker and smooth. Dens long, with 40-45 ventral chaetae, and 5 dorsal chaetae. Mucro rather large, tridentate. Basal hooks of dens normal. Derivatio nominis. The species is named after Bukit Barisan, the mountain range which runs throughout Sumatra island. Discussion (see I. deforestai n. sp.). No male in our material. Isotomiella Jeforestai n. sp. (Figs 9-12) Type material. Holotype female and 9 paratypes: «Lampung prov., Krui, Liwa, alt. 800 m, primary forest, soil, 29.5.1991, Deharveng leg.» (SUM 181); 38 paratypes as above (20 samples). Holotype and 35 paratypes in the collection of the LEITT; 10 paratypes in the collection of the MZB. Other material. «Jambi prov., Muarabungo, Rantaupandan, primary forest and kebun karet, 9 & 12.6.91, Deharveng & Bedos leg.» numerous specimens. Description. Length: 0.55-0.7 mm. Habitus like Isotomiella delamarei. No craters or secondary granules on body integument. No secondary granules on ant. IV. Integument channels present ventrally and laterally from head to abd. II, not seen on th. II. Pseudopora very small, often inconspicuous. Head. Anterolateral chaetae of labrum thickened but not spine-like. Maxillary outer lobe with bifurcate palp, without ciliated chaetae, and with 4 sublobal hairs. Antennae short (L:ant = 5.2). Chaetae S1-S6 of ant. IV subequal, ovoid-elongate. Supplementary S-chaetae of ant. IV subcylindrical, subequal, 1 internal and 3-4 external. Ant. I with 13-15 smooth ordinary chaetae, 2 basal microchaetae and 2 unequal S-chaetae (S:s = 1.3-1.6). All chaetae of head smooth, or a few ciliated in the posterior row. Tergites. Axial chaetotaxy from th. II to abd. IV: 16-18, 10-12 I 6, 6, 6, 6. Macrochaetae ciliated (with a low number of long cilia), erect, short, 1, 1 I 3, 3, 3 by half-tergite from th. II to abd. III. Macrochaetae Mdl and Md short (Mdl:Md = 1; Mdl:ML = 0. 7), hardly longer than mesochaetae on abd. I. Both ciliated and smooth mesochaetae present em tergites: th. II: 2 lateral and several in the posterior row ciliated, others smooth; th. III-abd I: most ciliated, some smooth; abd. II-III: ciliated between ML macrochaetae, smooth laterally; abd. IV-VI: most ciliated, some smooth. A ventro-lateral area devoid of chaetae, or with 1-2 chaetae anterior to the posterior row, on abd. II. On abd. VI, p1 is a long, smooth and thin macrochaeta, ao a smooth mesochaeta, mo a ciliated macrochaeta, po a smooth long mesochaeta. Formula of S chaetae of the minor-type: 3, 2 I 0, 0, 1, 3, 5 by half somite from th. II to abd. V. SL3 of th. II has not migrated towards the subcoxae. Spl of abd V very thick and relatively

Isotomiella from Sumatra 317 9 15 ClPr lujj ll \ l Figs 9-15. - Figs 9-12, Isotomiella deforestai n. sp.; Fig. 9, habitus; Fig. 10, manubrium and mucrodens ventrally (right), dens basis dorsally (left); Fig. 11, chaetotaxy of abd. V-VI; Fig. 12, left ant. IV with thickened S-chaetae; Fig. 13, I. dubia n. sp., chaetotaxy of abd. V-VI, dorsal view; Fig. 14, I. thiollayi n. sp., chaetotaxy of abd. V-VI, dorso-lateral view; Fig. 15, I. thiollayi n. sp., left ant. IV with thickened S chaetae. (Scales, Fig. 9: 100!J.m; Figs 10-15: 20!J.m).

318 L. Deharveng and Y.R. Suhardjono long, but variable in length (Spl:GIII = 1.1-1.8; M:Spl = 1.0-1.5); Sa, Spe and Spi of abd. V 1-1.5 as long as S-chaetae of abd. IV. Appendages. No spine-like tenent hairs on tibiotarsus III. Femoral tenent hair smooth on Felli. No spine-like chaetae on femora, trochanter or coxae. Subcoxae 1 of legs I, II and III with 1, 2-3, 2-(3) chaetae, all ciliated. Claw rather slender distally. Ventral tube with 4+4 distal, 3+3 anterior and 2+2 posterior chaetae. Tenaculum with 4 + 4 teeth and 1 chaeta. Subcoxae anterior with 8-12 chaetae (of which 5-6 ciliated), posterior with 8 ciliated chaetae. Manubrium with 2-4 + 2-4 ventro-distal (frequent asymmetries), no ventra-proximal and 2-3lateral chaetae. Dorsal chaetae on dens and manubrium smooth and thin, ventral chaetae thicker and smooth. Dens short, with 15-19 ventral chaetae in adult and 5 dorsal chaetae. Mucro large, tridentate, basal teeth small. Basal hooks of dens normal. Derivatio nominis. The species is dedicated to our friend, the botanist Hubert De Foresta, who organized our investigations in Krui and Rantaupandan. Discussion. Among the Isotomiella minor group, the loss of a dorsal chaeta on dens is observed only in two South-East Asia species. I. barisan n. sp. represents a primitive form in this line, with a non-reduced furca. I. deforestai n. sp. is more apomorphic, with the shortest furca of all Sumatra Isotomiella and a reduced chaetotaxy on both dens and manubrium. Other undescribed species intermediate between these two Sumatran forms are present in Thailand. I. deforestai n. sp. is probably a parthenogenetic species, as no male was found in the large material at hand. Isotomiells dubis n. sp. (Fig. 13) Type material. Holotype male and 1 paratypes: <<]ambi prov., Muarabungo, Rantaupandan, kebun karet, soil, 9 & 10.6.1991, Deharveng & Bedos leg.» (SUM 268); 20 paratypes as above (12 samples); 2 paratypes as above, except «primary forest». Holotype male and 18 paratypes in the collection of the LEITT; 5 paratypes in the collection of the MZB. Description. Length: 0.45-0.60 mm. Habitus like Isotomiella minor. No craters or secondary granules on body integument. Small, well distinct secondary granules scattered on antennae. Integument channels present from head to abd. II, distinct ventrally, laterally and on the anterior part of tergites. Pseudopora distinct. Head. Anterolateral chaetae of labrum thickened but not spine like. Maxillary outer lobe with bifurcate palp, without ciliated chaetae, and with 4 sublobal hairs. Antennae rather long (L:ant = 3.9). Chaetae S1-S6 of ant. IV subequal, ovoid. Supplementary S-chaetae of ant. IV subcylindrical, subequal, 1-2 internal and 5 external. Ant. I with 16 smooth ordinary chaetae, 2 basal microchaetae and 2 unequal S-chaetae (S:s = 1.5-2). All chaetae of head smooth. Tergites. Axial chaetotaxy from th. II to abd. IV: 20, 14 I 6, 6, 6, 6. Macrochaetae strongly ciliated, erect, short, 1, 1 I 3, 3, 3, 4 by half-tergite from th. II to abd. IV. Macrochaetae Mdl and Md short (Mdl:Md = 1; Mdl:ML = 0.4), hardly longer than mesochaetae on abd. I. Mesochaetae rather short. Both ciliated and smooth mesochaetae present on tergites: th. 11-111: 1 lateral ciliated, others smooth; abd. 1: all smooth; abd. 11-111: some ciliated, most smooth; abd. IV-VI: most ciliated. No ventro-lateral area devoid of chaetae on abd. II. On abd. VI, p1 is a ciliated

Isotomiella from Sumatra 319 macrochaeta, ao a smooth short mesochaeta, mo a ciliated macrochaeta, po a ciliated mesochaeta. Formula of S-chaetae of the minor-type: 3, 2 / 0, 0, 1, 3, 5 by half somite from th. II to abd. V. SL3 of th. II has not migrated towards the subcoxae. Spl of abd. V thick and long (Spl:GIII = 2.8-3.5; M:Spl = 1.4-1.5); Sa, Spe and Spi of abd. V about 1.5 as long as S-chaetae of abd. IV. Appendages. Tenent hairs of tibiotarsus III not spine-like, one dorso-internal slightly thickened and one dorsal thinner. Tibiotarsus III of male with 2 thin, erect stick-like x-chaetae. Femoral tenent hair of leg III smooth. No spine-like chaetae on femora, trochanter or coxae. Subcoxae 1 of legs I, II and III with 1, 1, 2 chaetae of which 1, 0, 0-1 ciliated. Claw plump. Ventral tube with 4 + 4 distal, 3 + 3 anterior and 2 + 2 posterior chaetae. Tenaculum with 4 + 4 teeth and 1 chaeta. Subcoxae anterior with 14-18 (usually 14-16) chaetae (of which 2 ciliated), posterior with 8 chaetae (of which 6-7 ciliated). Manubrium with 5 + 5 ventro-distal, no unpaired ventro-proximal and 3 lateral chaetae. Dorsal chaetae on dens and manubrium smooth and thin, ventral chaetae thicker and smooth. Dens rather short, with 24-28 ventral chaetae, and 6 dorsal chaetae. Mucro rather short, tridentate, distal tooth slender. Basal hooks of dens normal. Derivatio nominis. From its similarity to Isotomiella minor. Discussion. I. dubia n. sp. differs from I. thiollayi n. sp., its closest Sumatran relative, by a smaller size, absence of craters on integument, Spl(V) thicker and longer, shorter macro- and mesochaetae, shorter dens with less than 29 ventral chaetae. Subcoxae 1 with 1, 1, 2 chaetae [instead of 1, 3, 2-(3)], no ciliated chaetae on head, and ant. IV with S1-S6 more plump. The new species is even closer to the widespread temperate species I. minor, from which it differs by a reduced chaetotaxy on dens (less than 30 chaetae against more than 42 in minor populations of Pyrenees and Alps), on subcoxae 1 (1, 1, 2 against 1, 3, 3 chaetae), on posterior furcal subcoxae (8 chaetae against 9). IsotomieHs thiohsyi n. sp. (Figs 14-15) Type material. Holotype male and 1 paratype: «Jambi prov., Muarabungo, Rantaupandan, alt. 150m, primary forest, soil, 12.6.1991, Deharveng & Bedos leg.» (SUM 327); 14 paratypes as above (6 samples). Holotype and 9 paratypes in the collection of the LEITT; 5 paratypes in the collection of the MZB. Other material. «Lampung prov., Krui, Liwa, primary forest, alt. 800 m, litter and soil, 29.5.91, Deharveng leg.», 5 specimens (SUM 138, 142, 147, 157). Description. Length: 0.6-0. 7 mm. Habitus like Isotomiella minor. Numerous small craters on dorsal integument of body and head, reaching 1/3-1/2 (abd. V-VI) to 1/4-1/3 (head) of mesochaeta socket in diameter, sometimes hardly distinct. Small, very distinct secondary granules scattered on antennae, tibiotarsi and femora. Integument channels present from head to abd. II, distinct ventrally, laterally and on the anterior part of tergites. Pseudopora distinct. Head. Anterolateral chaetae of labrum thickened but not spine like. Maxillary outer lobe with bifurcate palp, without ciliated chaetae, and with 4 sublobal hairs. Antennae rather long (L:ant = 4). Chaetae S1-S6 of ant. IV subequal, ovoid-

320 L. Deharveng and Y.R. Suhardjono elongate. Supplementary S-chaetae of ant. IV subcylindrical, subequal, slightly thickened, 1 internal and 4-5 external of which the proximal one is thicker. Ant. I with 17 smooth ordinary chaetae, 2 basal microchaetae and 2 unequal S-chaetae (S:s = 1.6-2). Some chaetae in the posterior row of head sometimes ciliated. Tergites. Axial chaetotaxy from th. II to abd. IV: 20, 14 I 6, 6, 6, 6. Macrochaetae strongly ciliated, erect, long, 1, 1 I 3, 3, 3, 4 by half-tergite from th. II to abd. IV. Macrochaetae Mdl and Md short on abd. I (Mdl:Md = 0.7-0.8; Mdl:ML = 0.35-0.45). Both ciliated and smooth mesochaetae present on tergites: th. II-III: 1-3 lateral and most (th. II) or a few (th. III) anterior ciliated, others smooth; abd. I: most smooth; abd. II-III: smooth and ciliated chaetae; abd. IV-VI: most ciliated. No ventro-lateral area devoid of chaetae on abd. II. On abd. VI, p1 is a ciliated macrochaeta, ao a smooth mesochaeta, mo a ciliated macrochaeta, po a ciliated mesochaeta. Formula of S-chaetae of the minor-type: 3, 2 I 0, 0, 1, 3, 5 by half somite from th. II to abd. V. SL3 of th. II has not migrated towards the subcoxae. Spl of abd. V rather long and rather thin (Spl:GIII = 2-2.5; M:Spl = 2.2-2.6); Sa, Spe and Spi of abd. V about 1.3-1. 7 as long as S-chaetae of abd. IV. Appendages. Tenent hairs of tibiotarsus III not spine-like, one dorsa-internal slightly thickened and one dorsal thinner. Tibiotarsus III of male with 2 thin, erect stick-like x-chaetae. Femoral tenent hair of leg III smooth. No spine-like chaetae on femora, trochanter or coxae. Subcoxae 1 of legs I, II and III with 1, 3, 2-(3) chaetae of which 1, 1, 1-2 ciliated. Claw rather plump. Ventral tube with 4 + 4 distal, 3 + 3 anterior and 2 + 2 posterior chaetae. Tenaculum with 4 + 4 teeth and 1 chaeta. Subcoxae anterior with 17-18 chaetae (of which 2 ciliated), posterior with 8 chaetae (of which 6 ciliated). Manubrium with 5 + 5 ventro-distal, no unpaired ventraproximal and 3-4 lateral chaetae. Dorsal chaetae on dens and manubrium smooth and thin, ventral chaetae thicker and smooth. Dens rather short, with 29-32 ventral chaetae, and 6 dorsal chaetae. Mucro short, tridentate. Basal hooks of dens normal. Derivatio nominis. This species is dedicated to the ornithologist J.M. Thiollay, our field companion in Sumatra. Discussion. A slightly different form is found in the Krui area (Lampung), differing by a larger size and more chaetae on dens (37-38 against 30-32). lsotomiella cribrata n. sp. (Figs 16-17) Type material. Holotype female and 2 paratypes: «Lampung prov., Krui, Pahmungan, Kebun damar, alt. 70 m, soil, 23 to 27.5.1991, Deharveng leg.» (SUM 74); 19 paratypes as above (11 samples). Holotype and 16 paratypes in the collection of the LEITT; 5 paratypes in the collection of the MZB. Other material. «Jambi prov., Muarabungo, Rantaupandan, alt. 150 m, primary forest, soil, 12.6.91, Deharveng & Bedos leg.», 11 specimens (8 samples); as above, except «kebun karet, 9 & 10.6.91», 48 specimens (19 samples). Description. Length: 0.55-0.7 mm. Habitus like Isotomiella minor. Integument dorsally with numerous craters as large as sockets of mesochaetae on abd. IV-VI tergites, progressively less distinct towards abd. I, and not visible on thorax and head. Integument channels present from head to abd. II, clearly distinct only on the ventral side of head and laterally on th. II-III. Pseudopora hardly distinct.

Isotomiella from Sumatra 321 16 18 Figs 16-19. - Fig. 16, I. cribrata n. sp., left ant. IV with thickened S-chaetae; Fig. 17, I. cribrata n. sp., chaetotaxy around Spl of abd. V, with integument craters as dotted circles; Fig. 18, I. michonae n. sp., left ant. IV with thickened S-chaetae; Fig. 19, I. michonae n. sp., chaetotaxy around Spl of abd. V. (Scales, Figs 16-19: 25 11m). Head. Anterolateral chaetae of labrum thickened but not spine like. Maxillary outer lobe with bifurcate palp, without ciliated chaetae, and with 4 sublobal hairs. Antennae rather long (L:ant = 4). Chaetae S1-S6 of ant. IV subequal, ovoidelongate. Supplementary S-chaetae of ant. IV subcylindrical, subequal, 2-3 internal and 5-6 external. Ant. I with 17 ordinary chaetae of which 3-5 ciliated, 2 basal microchaetae and 2 unequal S-chaetae (ratio S:s = 1.7-2.1). All chaetae of head smooth. Tergites. Axial chaetotaxy from th. II to abd. IV: 20, 14 I 6, 6, 6, 6. Macrochaetae strongly ciliated, erect, long, 1, 1 I 3, 3, 3, 4 by half-tergite from th. II to abd. IV. Macrochaetae of abd. I much longer than mesochaetae: Mdl:Md = 0.6-0.7; Mdl:ML = 0.5. Both ciliated and smooth mesochaetae present on tergites: th. II: 1 lateral ciliated, others smooth; th. III: 2-3 lateral ciliated, others smooth; abd. I: all smooth; abd. II-III: several or most in the posterior row ciliated, others smooth; abd. IV: numerous ciliated, numerous smooth; abd. V-VI: most ciliated. No ventro-lateral area devoid of chaetae on abd. II. On abd. VI, p1 is a ciliated macrochaeta, ao a short smooth mesochaeta, mo a ciliated macrochaeta, po a ciliated mesochaeta. Formula of S-chaetae of the minor-type: 3, 2 I 0, 0, 1, 3, 5 by half somite from th. II to abd. V. SL3 of th. II has not migrated towards the subcoxae. Spl of abd. V rather long and rather thick (Spl:GIII = 1.35-1. 80; M:Spl = 2. 7); Sa, Spe and Spi of abd. V about 1.2-1.6 as long as S-chaetae of abd. IV. Appendages. Tenent hairs of tibiotarsus III not spine-like, one dorso-internal slightly thickened and one dorsal thinner and longer. No spine-like chaetae on femora,

322 L. Deharveng and Y.R. Suhardjono trochanter or coxae. Femoral tenent hair of leg III smooth. Subcoxae 1 of legs I, II, III with 1, 3, 3 chaetae of which 1, 1, 1-2 ciliated. Claw normal, rather plump. Ventral tube with 4 + 4 distal, 3 + 3 anterior and 2 + 2 posterior chaetae. Tenaculum with 4 + 4 teeth and 1 chaeta. Subcoxae anterior with 15-16 chaetae (of which 5-7 ciliated), posterior with 8 chaetae (of which 6 ciliated). Manubrium with 5 + 5 ventradistal, no ventra-proximal and 3 lateral chaetae. Dorsal chaetae on dens and manubrium smooth and thin, ventral chaetae thicker and smooth. Dens long, with 37-41 ventral chaetae, and 6 dorsal chaetae. Mucro short, tridentate. Basal hooks of dens normal. Derivatio nominis. The species is named from the numerous craters on the integument of abd. IV-VI. Discussion. I. cribrata n. sp. is characterized by the large number of craters on the integument of abd. IV-VI. It is otherwise not far from I. arlei Oliveira & Deharveng 1990 and I. sensillata Oliveira & Deharveng 1990, both from Amazonia, but has less chaetae on dentes (37-41, against more than 52), Scxa (15-16 against more than 21) and Scxp (8 against 9). I. cribrata n. sp. might have a large distribution in South-East Asia; a very similar form, if not identical, is present in Thailand. No male was found in our material. Isotomiella michonae n. sp. (Figs 18-19) Type material. Holotype male and 5 paratypes: «Sumatra Barat prov., Maninjau, Kotomalintang, alt. 750 m, kebun kulit manis, soil, 12. 7.1992» (SUM 443), Deharveng & Bedos leg.»; 5 paratypes as above except «alt. 700 m, kebun kulit manis- durian» (SUM 447); 4 paratypes as above, except «alt. 950 m, primary forest, soil, 9.7.92» (SUM 403,414, 419). Holotype and 10 paratypes in the collection of the LEITT; 4 paratypes in the collection of the MZB. Description. Length: 0.62-0.77 mm. Habitus like Isotomiella minor. Body integument dorsally with numerous craters as large as sockets of mesochaetae on abd. IV-VI, turning to small, sometimes unconspicuous granule-like structures on abd. 11-111 and usually not visible on thorax and head. Integument channels present from head to abd. II, clearly distinct only on the ventral side of head and laterally on th. 11-111. On ant. IV, hardly distinct secondary granules on the internal side. Pseudopora very distinct, made of 3-4 small granules. Head. Anterolateral chaetae of labrum slightly thickened, not spine like. Maxillary outer lobe with bifurcate palp, without ciliated chaetae, and with 4 sublobal hairs. Antennae rather long (L:ant = 3.5-4.5). Chaetae S1-S6 of ant. IV subequal, ovoid-elongate. Supplementary S-chaetae of ant. IV subcylindrical, subequal, (2)-3 internal and 7 external. Ant. I with 17-18 ordinary chaetae (of which 6-7 ciliated), 2 basal microchaetae and 2 unequal S-chaetae (S:s = 1.5-2). Posterior chaetae of head strongly ciliated. Tergites. Axial chaetotaxy from th. II to abd. IV: 20, 14 I 6, 6, 6, 6. Macrochaetae strongly ciliated, erect, long, 1, 1 I 3, 3, 3 by half-tergite from th. II to abd. III. Macrochaetae of abd. I long (Mdl:Md = 0.75; Mdl:ML = 0.6-0.7). Both ciliated and smooth mesochaetae present on tergites: th. 11:2-3 lateral, the anterior ones and some posterior ciliated, others smooth; th. III: 2-3 large lateral, a few anterior and a few posterior ciliated, others smooth; abd. 1: a few ciliated, others smooth; the proportion of ciliated chaetae increases more posteriorly; abd. V-VI: most ciliated. No ventrolateral area devoid of chaetae on abd. II. On abd. VI, p1 is a ciliated macrochaeta, ao

Isotomiella from Sumatra 323 a short smooth mesochaeta, mo a ciliated macrochaeta, po a large ciliated mesochaeta. Formula of S-chaetae of the minor-type: 3, 2/ 0, 0, 1, 3, 5 by half somite from th. II to abd. V. SL3 of th. II has not migrated towards the subcoxae. Spl of abd. V short and moderatly thick (Spl:GIII = 1-1.2; M:Spl = 4-4.6); Sa, Spe and Spi of abd. V about 1.8-2 times as long as S-chaetae of abd. IV. Appendages. Tenent hairs of tibiotarsus III not spine-like, one dorso-internal slightly thickened and one dorsal thinner and longer. No spine-like chaetae on femora, trochanter or coxae. Femoral tenent hair of leg III strongly ciliated. Subcoxae 1 of legs I, II, III with 1, 3, 2-3 chaetae of which 1, 2, 2 ciliated. Claw rather plump. Ventral tube with 4 + 4 distal, 3 + 3 anterior and 2 + 2 posterior chaetae. Tenaculum with 4 + 4 teeth and 1 chaeta. Subcoxae anterior with (16)-18 chaetae (of which 8-11 ciliated), posterior with 8 chaetae (of which 5-6 ciliated). Manubrium with 5 + 5 ventro-distal, 2-3 ventro-proximal and 3-4lateral chaetae. Dorsal chaetae on dens and manubrium smooth and thin, ventral chaetae thicker and smooth. Dens long, with 45-51 ventral chaetae, and 6 dorsal chaetae. Mucro rather large, tridentate. Basal hooks of dens normal. Derivatio nominis. We are pleased to name this species after Genevieve Michon, who organized our stay in the kebun durian of Maninjau. Discussion. The new species differs from cribrata n. sp. by the presence of 2-3 ventro-proximal chaetae on manubrium. ACKNOWLEDGEMENTS Field work was supported by the BIOTROP (Bogor, Java) and the French Ministry of Environment (project SOFT: «Agroforestry practices and conservation of biological diversity in tropical rainforests. Indonesian cases»). We thank Judith Najt of the Laboratoire d'entomologie, Museum National d'histoire Naturelle, Paris, for the loan of the type material of Isotomiella symetrimucronata. REFERENCES BAGNALL R.S. 1939. Notes on British Collembola. Entomologist's Monthly Magazine 75: 91-102. BARRA J.A. 1968. Collemboles du Gabon. Biologia Gabonica 5 (3): 189-216. DEHARVENG L. & OLIVEIRA E. 1990. Isotomiella (Collembola, Isotomidae) d'arnazonie: les especes du groupe delamarei. Annates de la Societe Entomologique de France 26 (2): 185-201. DELAMARE DEBOUTTEVILLE c. 1950. Recherches ecologiques sur la microfaune du sol des pays temperes et tropicaux. These Faculte des Sciences, Universite de Paris (A) 2416, 360 pp. LAWRENCE P.N. 1969. Isotomidae from Solomon islands (Collembola). Pacific Insects 11 (3-4): 545-559. MrcHON G. & BoMPARD J.M. 1987. Agroforesteries indonesiennes: contributions paysannes a la conservation des forets naturelles et de leurs ressources. Revue d'ecologie (La Terre et la Vie) 42: 3-37. MrcHON G., MARY F. & BoMPARD J. 1986. Multistoried agroforestry garden system in West Sumatra, Indonesia. Agroforestry Systems 4: 315-338. OLIVEIRA E. & DEHARVENG L. 1990. Isotomiella (Collembola, Isotomidae) d'amazonie: les especes du groupe minor. Bulletin du Museum National d'histoire Naturelle, Paris 12: 75-93. YAYUK R.S. 1989. Revised checklist of Collembola from Indonesia and its adjacent regions. Acta Zoologica Asiae Orienta/is 1: 1-22.