O Society fbr Tropical Ecologv

DIVERSITYOF FROM BORNEAN LOWLAND RAINFORESTTREES

Andreas Florenl, Klaus Riede2& Sigfrid Ingrisch2

lTheodor-Boveri-lnstitute,Department of AnimalEcology and TropicalBiology, Biozentrum, Am Hubland,D-97074 Wuerzburg, Germany 2Alexander Koenig Zoological Research lnstitute and Museumof Zoology,Adenauerallee 160, 53113Bonn, Germany

Absnact.The composition and colonization dynamics of arboreal Orthopteran communities were studied in a SE-Asian mixed dipterocarp lowland rain forest by insecticidal fogging, re-fogging after different periods oftime, and by srem eclecrors during different times of the year. In total, 2324 Orthoptera were collected by fogging, of which 87 .3o/o were nymphs. Imagines were sorted to 49 morphospecies, ofwhich 47 (96ok) were new to science.Almost 500/owere singlerons, and only three , all belonging to the omnivorous subfamily Mogoplistinae (gents Ornebius), occurred with more than I 0 adult individuals. Orthoptera seemedto be randomly distributed in the canopy without showing any host-tree-specific adaptation. This is also indicated by the re-foggings, in which Orthoptera colonized the trees, according to the relative proportions ofsubfamilies and feeding guilds occurring in the canopy. No pioneer or climu speciescould be distinguished. ln the stem eclectors787 specimenswere caught, ofwhich 98.20lowere nymphs, mostly first and second instar, indicating migration into the canopy after egg development in the soil or lower forest strata. In contrast to the numerous nymphs of hemimetabolous taxa, lessmobile , mainly larvaeof holometabolous groups, were almost completely lacking in the canopy. This is probably due to the high predation pressureof the ants which influence communiry composirion. Arepted 9 July 2001.

Kry words: Ant predation, canopy fogging, colonization dynamics, diuersity, hemimetaboly, stem eclectors.

INTRODUCTION distinguished: the Caelifera ("")which are diurnal and herbivorous, showing all varietiesof the The existenceofan extremely diverse fauna specialist-generalistcontinuum (Rowell 1978), and in the canopy oftropical lowland rain forest, as first "karydids" "crickets") the Ensilera(mainly and which suggestedby Roberts (1973) and Erwin (1982), has are nocturnal and comprise a wider range of feeding sincebeen confirmed by various investigations(refer- habits, including herbivores, predators, and omni- ences,e.g., in Stork et dl. 1997, Linsenmair et al., in vores. To date, most studies have locused Neo- press),raising the question ofhow such high diver- on siry is maintained (e.g., Beaver 1979, Huston 1994, tropical Caelifera, which were collected either by (Roberts Linsenmair 1995, Pianka 1996, Price et al. 1995, Fogging I 973) or tree-felling,and netting of (Descamps Rosenzweig1995). This is the locus of our project in grasshoppersat ground level 1978, 1981). SE Asia that aims at understanding the mechanisms Those studies revealeda species-richcanopy fauna and structuring arboreal arthropod communities. In this gaverhe firsr insighrsinto communiry strucrure.re- paper we consider the Orthoptera, which usually source partitioning (Amdddgnato 1997), and ethology account for berween I and 3 o/ooF the specimens in (Riede 1987). Although the Ensiferan launa oftrees tree communities (Stork 1991, Floren & Linsenmair is generally much more diverse than the Caeliferan 1997,'S7agner1997). In contrast to previously ana- launa, the arboreal Ensilera remain largely unstudied. lJzed orders from the canopy, Orthoptera are Here we present for the first time an analysis of hemimetabolous. Their nymphs are usually highly complete Orthopteran communities from trees in a mobile and basicallybelong to the sameleeding guild SE-Asianlowland rain lorest,which were sampledby as the adults. Two major groups ofC)rthoptera can be fogging, re-fogging, and stem eclectors. \7e describe the Orthoptera launa associatedwith three tree spe- e-mail: fl oren@biozentrum. uni-wuerzburs.de cies, in terms of their diversiry and re-colonization 33 dynamics (of the primary fogged rrees) and ask how one A. lagenocdrpatree was re-fogged on Four conse- c important tree trunks are as pathways [or canopy cutive mornings. colonization. Furthermore we investigate whether Stem photo-eclectors(emergence traps) were in- ( differencesin life history featuresof holometabolous stalled on 47 tree trunks at 4 m height in order to I and hemimetabolous taxa have an effecr on the struc- quanti$/ arthropod immigration into the canopy c ture oFtree-dwelling communities. along tree stems lrom the ground (these were 35 t A. lagenocarpa, 4 A. subcaudata, 4 Depressaneruosa c MATERIALS AND METHODS (Guttiferaceae),and 4 unidentified trees.Their bark T was only slightly structured and not covered with Study site and samplingprocedures.Investigations were S thalloid epiphytes.For the operational method ofthe c conducted in Kinabalu National Park, substation Por- eclector-traps seeBasset et al. (1997). The traps were c ing Hot Spring, Sabah, Malaysia, Borneo (6"5'N, filled with 4o/o formalin solution and emptied every l 11633' E), in a floristically rich mixed dipterocarp fwo weeks.A total of 171 sampleswas evaluared. l, lowland Forest(500 to 700 m a.s.l.).The region is t characterized by a rypical tropical climate with at Arthropod sorting and data anallsh. Orthoptera were I least2000 ml precipitation per year (Kitayama 1992, separatedand sorted to morphospeciesby one o[ us t Pfeiffer 1997). All investigations were done after the (SI). However, most of the nymphs could be identi- c rainy seasons(which last from February ro May and fied only to subfamily level, therefore evaluation is i August to end of November) during lour field stays only based on adults. Classification lollowed the c between 1992 and 1993. Orthoptera SpeciesFile (One & Naskrecki 1997). An improved method of canopy logging was used Specimensfrom the studies have been deposited in to sample arthropod communities associatedwith the Museum Koenig, Bonn or in the institutions men- c individual trees.Since methodical details have been tioned in the resulting taxonomic publications. In published elsewherewe give only basic information addition, various persons kindly provided data from € € here (Floren & Linsenmair 1997,2000). The trees hand collecting and light-traps which were conrrasred C were fogged For ten minutes with natural with the fogging material. pyrerhrum f Shinozaki curves were calculated to comDare com- used as insecticide early in the morning and all ar- t thropods that had dropped into the funnels after rwo munitiesar rhe bera-diversitylevel (Shinozaki 1963, C hours lollowing fogging were used in the analysis. Achtziger et al. 1992). These are expected species Nineteen medium-sized trees of the canopy un- accumulation curves and their steepnessprovides derstory, representing three speciesfrom nvo lamilies, inlormation about the overall complerenessof the (a were fogged. These were ren Aporusa lagenocarpa,fle sampling effort more comprehensivediscussion is I A. subcaudzta(both Euphorbiaceae),and foturXan- given in Floren & Linsenmair 2000). In addition, s toph/lum afine (Polygalaceae) (we recognized only Soerensentindex was used to measuresimilariry in (Magur- T during the investigations that the Euphorbiaceae trees speciescomposition berween communities ran : belonged to two species).A. lagenocarpawas rhe on- 1988). For a benveen comparison, the fogging data were ly speciesthat occurred in larger numbers in our re- standardized lor a crown projection of I m2 and a leafcover 1 search area of which sufficient available individuals oF 00o/o.Bonferroni's correction was used to adiust the level of significance for multiple were lound that were not covered with lianas. All trees pairwise comparisons (Lehmacher et al. 1991). were smaller than 30 meters in height and similar with respectto insecthabitat conditions, for examplecon- cerning the existenceofstem cavities, dead wood, and RESULTS detritus accumulations, etc.; epiphytes were almost A total of 2324 individuals of Orthoptera was ob- completely lacking (Floren & Linsenmair 1998a). tainedby fogging.The numberof specimenscollected Only one l. lagenocarpaflowered during one samp- on treesfogged for the first time variedconsiderably ling period, however,without a noticeable elfect on berween7 and,238,representing beween0.72o/o and the speciesabundance patterns. All trees showed con- 3.4o/oof all foggedarthropods. The proportionof tinuous leaf flushes of low intensity. Ten trees (five nymphs within primary fogging samplesfluctuated A- lagenocarpa, three ,4. subcaudata, and wo X. ffi- berweenB0 and 100o/o(nean 82.94t 19.59).This nde) were re-fogged at least after six months, nvo l. patternwas independent ofthe monthoflogging and subcaudata trees were fogged again alter a week, and showedno seasonaliry.In the stemeclectors, 787 spe- 34 DIV!,RSI'fY OF ORTHOPTEM FROM I]ORNEAN LO\flLANt) RAIN FORIST TREES

cimens were collected, and the proportion of nymphs All other taxa were represented by only a lew indivi- was significantly higher than in the fogging samples duals or singletonsin each sample.A remarkablege- (mean 96.9 + 5.28, Mann \Whitney U-test, P< 0.001). neral leature was the low percentage ofshort-horned Table I comparesthe higher taxonomic composirion grasshoppers (Caelifera) which were represented by o[fogged Orthoptera versus those caught by eclector only 32 nymphs in the fogging samples. They oc- traps, ranked by the number of nymphs. Adults curred as single individuals or in small groups of up occurred only sporadically in the stem eclectors. to lour () or ten individuals (Eumasta- Highest in abundance in both logging and eclector coidea). Tetrigoidea always occurred as singlerons; samples were the Podoscirtinae (hard-footed bush three of the specimens lound in srem eclectors were crickets). In the fogging samples,Mogoplistinae (scaly adults. crickets) followed in second place, but had by far the For the , Thble 2 compares the number highest number of adults. The differences between of adult speciesand their taxonomic status in the larval:adult proportions of the dominant Podoscir- fogging samples with those collected by hand and tinae and Mogoplistinae point to differences in the by light-traps. A total of 127 morphospecieswere life cycle; however we cannot exclude the possibiliry difTerentiated,of which 85 were new;32o/o(4I1127) that this result was influenced by dilferences in flight of all specieswere obtained by fogging only. Vithin capabiliry (adult Podoscirtinae are fully winged fly- the fogging samples the proportion of new species "only''497o ing species,while in Mogoplistinae the wings are re- was 989/0,while ofspeciescollected with duced or absent and they are unable to fly). In the conventional methods were new. Only 8olo (6176) of eclectortraps the Mogoplistinae dropped to rank six, tenigoniid and 2o/o (1144) of grylloid specieswere while the omnivorous rose ro rhe se- collected both by fogging and convenrional methods. cond rank. Pteroplistinaefirst-instar nymphs formed Such a small overlap suggests the existence of a se- "Canopy'' groups ranging between 7 and 25 individuals, sug- parate canopy fauna. taxa ('only fogging') gesting that nymphs climbed up the stems imme- which provided most new specieswere Pseudophylli- diately after hatching in the soil, lower vegetation, or nae, Meconematinae, , Podoscirtinae, from crevicesin the bark. In contrast, the low num- and Mogoplistinae. Most other groups were collected bers of Mogoplistinae nymphs in the eclectorsindi- predominantly by conventional merhods, indicating cate a preFerencefor the canopy throughout their life. a oreference for lower forest srrara.

TABLE I . Ranksof Orthopteran groupsaccording to the number of nymphs collectedby toggingand with stemeclector traps. Guild assessmentaccording to feedinghabits: H = herbivorous,O = omnivorous,P = predators.

Fogging Stem-eclectors RankGroup Cuild Total Adults o/o Nymphs Total Adults o/o Nymphs Rank Adults Adults

I Podoscirtinae H 826 40 4,8 786 326 2 0,6 324 I 2 Mogoplistinae o 545 161 29,5 384 35 5 14,3 30 o 3 Meconematinae P 3r8 34 r0,7 284 75 4 4 Tiigoniinae H? 161 22 r3,7 139 38 -38 5 5 Gryllacridoidea o 171 11 6,4 160 78 2 2,6 76 3 6 Pteroplistinae o 101 4 4,0 97 186 I 0,5 r8t 2 7 Phaneropterinae H 84 t4 16,7 70 29 _29 7 8 Pseudophyllinae H 577 12,3 t0 ll I 9,r 10 8 9 o L\) -26 1 -19 10 Lipotactinae P )L66,7 1 0 11 Caelifera H 2a 3 37.5 5

Total 2324 295 2029 787 t4 773

35 TABLE 2. Speciesnumbers and taxonomic status of adult Ensifera collected by fogging and conventional techniques (hand collected and light-traps).

Only logging Only hand & Collectedwith Total light sampling both methods Total New Total New Total New Total New TETTIGONIOIDEA Phaneropterinae 2 2 20 r3 4 4 26 19 Pseudophyllinae 4 3 I6 6 0 0 209 Meconematinae 5 5 I I 0 0 66 Mecopodinae 0 0 4 0 0 0 40 Conocephalinae-Conocephalini 0 0 2 0 0 0 20 Conocephalinae-Agraecini 0 0 12 7 1 0 137 Conocephalinae-Copiphori ni 0 0 2 0 0 0 20 Hexacentrinae 0 0 1 0 0 0 l0 Lipotactinae 0 0 I 1 I 1 22 Sum 1l 10 59 28 o 5 76 43 o/onew species 91o/o 48o/o 83o/o 57o/o

GRYI-LOIDEA Podoscirtinae t2 t2 3 3 I I l6 l6 Pteroplistinae 2 2 2 2 0 0 4 4 Mogoplistinae 5 5 0 0 0 0 5 5 Trigoniinae 4 4 0 0 0 0 4 4 Nemobiinae I I 3 0 0 0 4 I Gryllinae 0 0 2 I 0 0 2 I Itarinae 0 0 4 2 0 0 4 2 Eneopterinae 0 0 I U 0 0 I 0 Oecanthidae 0 0 I 0 0 0 I 0 Myrmecophilidae 0 0 I I 0 0 I I Gryllotalpidae 0 0 2 I 0 0 2 I Sum 24 24 19 10 1 I 44 35 7o new species I00o/o 53o/o l00o/o 80% GRYI-LACzuDIDAE o o 0 0 I I 7 o/onew species 100o/o 100% l00o/o TOTAL 41 40 78 38 B 7 127 85 7o new species 98o/o 49o/o 880/o 67o/o

Composition and recolonization dynamics of the Orth- rubidusby 11 individuals. Even the more abundant opteranfauna. The rank-abundance plot ofall fogg- speciesdid not aggregateon particr,rlartrees, occurring ings (Fig. 1) gives the rypical pattern o[species dis- on almost every tree with some individuals irrespective tribution known From tropical lowland rain forests, ofthe tree species(Fig. 1). The steep increaseofthe with almost all speciesbeing rare as adults. The ma- Shinozaki curves (Fig. 2) and the low Soerensen jority of all specieswere singletons (49%) and only indices (Table 3) demonstrate that speciesoverlap three species (all Mogoplistinae) were lound with among individual trees was low, and that overall more than ten individuals; Ornebius marginatus re- samplingeflort wasnot suflicientto representor esti- presentedby 67 individuals, O. flori by 48, and O. mate total speciesnumber at the regional or even local 36 't DlvflRsl'l Y ol- oRl HoP'lf-RA I-RoN{ BoRN!_AN l.o\(/l.ANt) RAIN FORI-_S] RI-.I-.S

o c G o c Omebiusrubidus f -o o) o J

11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 RankedSpecies

FIG. 1. Rank-abundance curve plotted for the Orthoptera oFall fogs,

60

o a-- uJ ll oo @ '6o o-O30 a c o20 o c) o- .^ x tu

0 15 20 25 Samples= q

FIG. 2. Shinozaki curves computed for primary logged trees, lor all foggings, and lor all loggings excluding the most numerous Ornebiusspp.q = number of discretesamples (fogged trees),ES(q) = expectednumber of speciesin q samples.

2a FI-OREN f7',41-.

TABLE 3. Mean beta-diversities berween the fogged when the composition of the feeding guilds benveen trees expressedby the Soerensen index. Standard de- the various times of foggings were compared (Fig. 4b). viations in brackets. Guild classification corresponds to that ofThble I and distinguishes omnivores, herbivores, and predators. Tlee species Soerensen Only predators in the daily samples differed signifi- (n =10) A. lagenocarpa 0.16(0.17) cantly from the other foggings (K-W-Anova, 12 = A. subcaudata (n =5) 0.16(0.r4) 9.39, P = 0.024), causedby an increasein Mecone- X. afine (" = 4) 0.28 (0.34) matidae which were the lastestnewcomers (seeFig.4). All trees 0.20(0.21) DISCUSSION

Characterization of Orthopteran communities. Arthro- pod diversiry in tropical rainforests, and in particu- scale. The Shinozaki curves are far from reaching lar in the canopy, has received much attention during an asymptote, independently of whether all fogging the last decade, but analysis has been mainly based samples (primary- and re-foggings), only primary on Coleoptera and Formicidae (e.g., Erwin 1982, foggings,or only sampleswithout the most common Stork 1991, Basset1996, Stork er al. 1997, Linsen- Ornebius spp. were included in the calculation. mair et a|.2001). Ve here present data on the Or- Adding species captured in the re-fogging expe- thopteran fauna of three Bornean lowland rain forest riments always resulted in a larger number of new spe- tree species,considering both adults and nymphs. The cies, without changing the steepnessof the curve. constant high percentage ofnymphs within each tree Fig. 3 shows the standardizednumbers of Orth- crown community was independent of the month of opterans From the trees fogged lor the first time and fogging and indicates continuous reproduction in those re-fogged at various intervals of time. The num- most species.Despite quite a substantial sampling F ber oF individuals within daily re-loggingswas signi- effort, relatively lew adult specimens(representing only Ft ficantly lower than those ofthe primary fogged trees c (Mann-Whitney = U-test, P 0.007) and also than o those of the re-loggings after 6 months (M-!? U-test, P -- 0.002). The number of individuals caught in the daily samplings was not significantly different from o that obtained by weekly sampling due to an outliet o t:f o and the samewas true for all Orthopterans collected (I' I weekly and in comparison to those collected after ;l r more than six months. However, lew because of the o c samplesinvolved this lack of significanceshould not L o t be taken too seriously.The proportion of nymphs was .N E ol I equally high in trees fogged for the first time (87o/o) o t 41 and in those re-fogged after one week and after six c il o I s 2' months, but lower in samplesderived from daily re- a -Tt T toggings (66%). 0i + ' - t F"S 1 For all loggings the majority of specimenscap- weFt6 month I together contributed between of all specimens 760/o FIG. 3. Mean numbers oFOrthopteran individuals I in the daily samples and 90o/o in the samples taken calculated for a crown projection of 1m2 and a leaf after six months. Only the Podoscirtinaeand Meco- cover of 1000/o.Primary foggings (n = l9) are com-

nematinae showed significant variation in numbers pared with re-foggings after different intervals of time. I under different fogging regimes (for the Podoscirtinae: Daily: Four re-foggings of a single tree on four con- K-W-Anova, y2 = 11.34, P = 0.010; for the Meco- secutive days; l7eekly: re-foggings offour trees after 'Unknown' nematinae: X2 = 9.46, P = 0.024) (the one week; > 6 month: re-foggings often Aporusa-trees group was not considered).A similar pattern emerged after six months. 38 DIVERSITY OF ORI'HoP'I't,RA FII,OI\{BORNI.-AN I,OVI,AND RAIN FORI.-S'I1'REES

not been sampled from the ground (Riede unpub- lished),and were new to science(lngrisch 1998), thus indicating that they are confined to the canopy. Re- o 6 cent studies reveal that at least some speciesof the o Podoscirtinae do not need to go to the soil in any part o ! oftheir life cycle,lor example for egg deposition (In- _c s grisch I 997). Howeveq for most speciesobservations oTi@niinae on life habits are lacking. The lact that we also col- sGryllilddoidea a0EE lected juveniles oFall instarsofthese speciesby fogg- ing suggest they are really canopy specialists. Fog 1 Daily Weekly > 6 month Our data do not allow us to draw any conclusions about the existenceof a tree-species-specificOrth- opteran community. However, host tree adaptation might emerge if sampling effort were significantly a extended and if nymphs, which belong to the same o feeding guilds as adults, could be included in the ana-

! lysis. However, an adequate consideration of nymphs s would require comprehensive taxonomic and aute- cological studies.A preliminary analysisof a further 39 foggings in the mature forests, which include ten additional treespecies, does not show a changein the Fog 1 Daily Weekly > 6 month pattern describedabove (Floren unpublished). Trees in general seem to provide similarly lavorable condi- sub- FIG. 4. Relative proportion of a) Orthopteran tions for omnivorous species,and no differencesin composition in foggings family- and b) leeding guild habitats- like the presenceofepiphylls, stem cavities, carried out after diflerent periods of time. Labeling aggregationso[ detritus, etc. - were lound (Floren offogging categoriesas in Fig. 3. & Linsenmair 1998a). The failure to identify a tree- species-specific Orthopteran communiry corresponds with the findings lor other taxa, such as Coleoptera (e.g., Floren & Linsenmair 1998b, lTagner 1999), Ichneumonidae (Horstmann er al. 1999), or Formi- 13o/oof all specimens)were collectedand assignedto cidae (Floren & Linsenmair 1997, 2000), but see morphospecies. Our sampling revealedsurprising spe- the study by Amdddgnato (1997) on of an cies richness:all fogged and 91% of Tet- Amazonian rain forest. The question of how many ar- tigonioidea belonged to hitherto undescribed taxa. thropod speciesare tree specialistsis still intensively methods (light-trapping, Even conventional collection discussed (Erwin 1982, Basset 1996, Basseret al. hand collecting, and stem eclectors)revealed 49o/o oF 1996, Mawdsley & S species as new. rcrk 1997, Oedegaard 2000). In addition, the lack As is rypical for tropical insect faunas, the majo- oFthe existenceof a tree-specificcommuniry is sup- riry of Orthoptera speciesoccurred in small numbers ported by our result that Orthoptera were obviously and sampling effort was much too small to represent sampledat random lrom a largespecies pool: neither local speciesdiversity or even to assessthe necessary the taxonomic nor the guild composition of Orth- Further sampling effort required lor reliable estimates. opteran communities had changed significantly in The highest ranks in speciesrichness and abundance the re-fogging samples. Orthoptera colonize trees rat- among fogged species- considering adults as well as her slowly compared to Coleoptera and Diptera, nymphs - were occupied by rwo subfamilies which can reach original abundances already after one - Podoscirtinae and Mogoplistinae. However, only day (Floren & Linsenmair 1998a). Vhile the total two speciesof Mogoplistinae ( Ornebius),which number of Orthoptera dropped significantly in the are generalist feeders,occurred on all tree individuals. daily foggings,the proportion o[adults and nymphs These specieswere lacking in the stem eclectors, have did not change.The predatory Meconematinae we- 39 "canopy re the lastest colonizers. However, relative proporti- most analysesoF faunas" have been limited RT ons showed no significant differences from the ori- to adult holometabolic .Already in our first Acl ginal conditions already after one week, indicating fogging samples we recognized that nymphs of holo- that most specimens enter tree crowns from neigh- metabolous species were almost completely lacking boring treesaccording to their frequency in the spe- in the trees (Floren & Linsenmair 1997,1998a,b, cies pool, without tree-species-specificfeatures being 1999). Their absencefrom the tree crowns was con- Ar important. From our data we were not able to di- firmed by additional hand collecting, close observa- stinguish either pioneer or climax species,such aswe- tions in the trees (Riede, unpublished), and further re identified by Amdddgnato & Descamps (1980) in foggings. In contrast, nymphs of hemimetabolous ta- large lorest gaps and anthropogenic clearings. xa, especiallyof the numerically dominant Hemip- 'We compared our results with logged material tera and Orthopteroidea sensulatu, are lound regu- from Sulawesi(see Knight & Holloway 1990). As in larly and in high abundances,always outnumbering our investigation, Podoscirtinae and Mogoplistinae adults. This difference can be explained by the high were dominant there. Podoscirtinaeincluded almost predation pressureofthe ants, that dominate all trees Asl rwice as many larvae as Mogoplistinae, but Mogo- and patrol in the canopy regularly (Floren submitted). plistinae were more numerous as adults. There were Experimental feeding with caterpillarsdemonstrates four speciesof Mogoplistinae (probably undescribed) the high predation pressureexerted by canopy anrs, which belong to the genera Ectatoderus and Ornebius Bai most of which attacked lessmobile prey. By contrast, and which are specificallydiflerent from the species the nymphs of hemimetabolous groups are highly mo- occurring on Mt. Kinabalu. This might indicate a bile and thereforeable to escapelrom predatory ants. high degreeof endemism for the fauna of the region Similarly, eggs have to be protected by endophytic or lJar oFMount Kinabalu, which is a center of diversiry in subterranean oviposition. Nymphs which hatch in the SE Asia (Ashton 1989, Myers et a|.2000). soil or lrom the lower vegetation layers could then The extreme rariry of short-horned grasshoppers climb up to the canopy to complete their life Bar (Caetifera) in our sampleswas surprising and is in con- rycle. This might be an explanation lor the higher per- trast to Amazonian and Costa Rican rain lorests centageof nymphs observedin our eclectorsamples (Roberts 1973, Descamps1981, fuede 1993, Amd- compared with the logging Ba ddgnato 1997). Arboreal grasshoppersare characte- samplesand points to the rized by a vivid coloration, stout legsand body form, importance of tree trunks as routes to reach the ca- "dendro- and protuberant eyes, summarized as the nopy. On the other hand, in severaltettigoniid sub- (1976, families (Phaneropterinae,Pseudophyllinae, Meco- philous" life lorm by Descamps 1981).Many Be speciesare brachypterous or apterous. Some species nematinae) endophytic oviposition prevails,and the same could be true for the cricket sublamily Podos- have developed endophytic and epiphytic egg-laying Dt strategies,which would allow them to spend their cirrinae,which was rhe dominant taxon in our inve- whole liFecycle - from egg to adult - in rhe canopy stigations.This could mean that many of the arbo- (Amdddgnato 1997). An analysisof museum speci- real speciescomplete their life rycles in the canopy. Dt mens shows that the SE-Asian grasshopperlauna con- However, given the present state of knowledge these tains similar dendrophilous specieswhich are, how- interpretations must remain speculative,since biolo- ever,very rare (Riede I 993). This is corroborated by gical information on tropical Ensifera is generally Dr fogging studies by Stork (1991) in Brunei, and the scarce(e.g., Bailey & Rentz 1990). additional 39 loggings of 10 tree specieslrom seven lamilies in Kinabalu Park (Floren unpublished). The ACKNO\vLEDGMENTS rariry oF CaeliFeradoes not seem to be a sampling 'W'e Er are grateFul to the Director of Sabah Parks, Da- artifact. Among the possible causesof this rariry Riede tuk Ali Lamri, lor authorization of our research,and (1 993) discusseshigher predation pressureand canopy to park staff For generous support. The logged ma- structure as well as food plant availabiliry and pa- Fl, terial from Sulawesiwas kindly lent by Mar- tatabiliry. Howevet we must admit that Caeliferan Judith shall (Natural History Museum London). tWe thank scarcity in SE-Asian rainlorestsis still an enigma. C.H.F. Rowell For critical comments on the ma- Dffirences between ho/ometabolous and hemimetabolous nuscript. This study was supported by the German arthropods that ffict community composition.-lo date, ResearchCouncil (DFC), Li l50l13 14. 40 DIVI'.RSlIY Ol ORfHOP I I'-RAIjR()NI IIORNI:AN t-O\(l.ANl) IIAIN I()RflST TRI'-!'S

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