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Flowering mechanisms, pollination strategies and floral scent analyses of syntopically co‐ flowering Homalomena spp. () on Borneo

ARTICLE in BIOLOGY · JANUARY 2016 Impact Factor: 2.63 · DOI: 10.1111/plb.12431

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Marc Gibernau Wong Sin Yeng French National Centre for Scientific Research University Malaysia Sarawak

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All in-text references underlined in blue are linked to publications on ResearchGate, Available from: Wong Sin Yeng letting you access and read them immediately. Retrieved on: 26 January 2016 Hoe Y.C. Campo Grande, Brazil 3 Programa de Pós-graduação em Biotecnologia, Universidade Católica Dom Bosco, 79117-900 Sanguinaires F-20000 Ajaccio, France 2 CNRS - University of Corsica, UMR 6134 - SPE, Natural Resources Project, Vignola Rte des Technology, Universiti Malaysia Sarawak,Malaysia 1 Department of Plant Science and Environmental Ecology, Faculty of Resource Science and This article is protected Allrights bycopyright. reserved. Accepted10.1111/plb.12431 of Record.versiondifferences and article Please between the cite this Version this as doi: through the copyediting, typesetting, pagination for publication accepted This articlehasbeen Articleflowering Flowering mechanisms, pollination strategies an Editor : A. Dafni Article type : Research Paper 12-Jan-2016 : Date Accepted :21-Dec-2015 Date Revised :26-Oct-2015 Date Received 1 Homalomena , M. Gibernau spp. (Araceae) onBorneo 2 , A. C. D.Maia 3 & Wong S. Y. and undergone full peer review buthasnot been review undergone fullpeer and and proofreading process, which may lead to d floral scent analyses of syntopically co- syntopically of analyses scent floral d 1

This article is protected Allrights bycopyright. reserved. taxa belong to three out of four complexes of the section Borneo. The floral scent compositions were also recorded for six species thereof. The selected diverse In this study, the flowering mechanisms and pollination strategies of seven species of the highly ABSTRACT E-mail: [email protected] and Technology,Science UniversitiMala Wong S.Y., Department of Plant Science and Environmental Ecology, Faculty of Resource Correspondence Chaloenus schawalleri Chaloenus Scarabaeidae, Rutelinae) are the pollinat Our observations indicate that scarab beetles ( uncommon compounds in high concentration, wh samples of those belonging to the Giamensis complex. The floral scent blends contained analyses of species belonging to the Hanneae pistillate phase. A total of 33 volatile organic co Borneensis complexes, floral emission wa scent the pistillate and staminate phases of anthesis the Hanneae complex underwent two floral scent hrs) than those of the Giamensis and Borneensis Borneensis). The species belonging to the Hanneae complex exhibited longer anthesis (53 – 62 Acceptedrewards. -breeding flies( pollinators utilise the inflorescence for food, mati Article Homalomena (Chrysomelidae, Galeuricinae) acting asasecondary pollinator. The (Araceae) were investigated in native populations of West Sarawak, Colocasiomyia nigricauda Colocasiomyia ysia Sarawak, Sarawak,Malaysia. ors of the investigated species of complex, whereas 26 VOCs were found in . Inspecies belonging to the Giamensis and Parastasia mpounds (VOCs)were detected in floral scent s only evident to the human nose during the belonging (ca30 hrs).Species complexes to ng opportunities and safe mating arena as ich could ensure pollinator discrimination. emission events in consecutive days, during

and gestroi Cyrtocladon C. aff. and heterodonta P. nigripennis P. (Hanneae,Giamensis and Homalomena ; Diptera, ; , with Wong Engl. &K.Krause, and within into the resurrected genus This article is protected Allrights bycopyright. reserved. 2011; Wong Born complexes: four of consists currently with strongly aromatic tissues, and pleionanthic shoot modules (Boyce & Wong 2008). It restricted to Borneo. Species in this section are medium to very large, erect to creeping Neotropical The 2013). &Croat Asia (Boyce be most offormally described; a arethem fewspecies Malesian, with from continental tropical Homalomena INTRODUCTION 4,8-dimethyl-1,3,7-nonatriene. Flowering phenology; floral scent attractants; scarab beetle pollination; Keywords sharing the same visiting insects. also frequently recovered from inflorescences Drosophilidae)and terrestrial hydrophilid beetles( investigate the postmating isolating ba velutipedunculata Acceptedand their host inflorescences (Okada 1986; Sultana interactions between flower-breeding flies of the genus Article et al. et Homalomena Pollination studies in 2013b). Section Section 2013b). et al. et Schott comprises 75 described species and no fewer than 500 novel species yet to 2013b). ), but they probably do no : Homalomena Homalomena Geniculatae Adelonema Cyrtocladon Homalomena Hotta (Mayo Schott, Schott (Wong rriers among syntopically co-flowering comprises at least comprises at 300 novel species,many whichof eensis, Giamensis, Hanneae and Rostrata (Ng (Ng eensis, Hanneae andRostrata Giamensis, wereinitially directed at investigations of the Cyrtocladon Homalomena t act as efficient pollinators. Future studies should belonging to of allstudied species (except et al. Cycreon et al. al. et 1997; Boyce &Wong 2008; Ng et al. et (Griff.) Furtado, Colocasiomyia

2006). While, without doubt, many taxa have been recently transferred 2016). Four sections are recognized sp.;Coleoptera, (Diptera, Drosophilidae) Chamaecladon sec -butyl acetate; ( Hydrophilidae) were Homalomena et al. (Miq.) (Miq.) et al. H. 2011; E

)-

inflorescences (Tung staphylinid beetles (Staphylinidae) are also frequently found in association with Galeuricinae) (Kumano-Nomura &Yamaoka 2009; Hoe also possibly by chrysomelid beetles of the genera This article is protected Allrights bycopyright. reserved. single species (an undescribed taxon mistakenly identified as 2010; Hoe early morning hours (Kumano & Yamaoka 2006; Kumano-Nomura & Yamaoka 2009; Tung inflorescences open at dawn and emit strong, fruity-spicy fragrances to attract pollinators in the syntopicallywith nohybridsbeing observed several species from any of sections orthe co & Yamaoka 2006; Kumano-Nomura &Yamaoka 2009; Tung in fact pollinated by scarabbeetles of the genus the sister taxon to arearoids pollinated by 1999). morphology (Knudsen 1999), habitat, flowering period and/or pollination mechanism (Knudsen et al. floral scents provide significant data in species boundary delimitation for angiosperms (Dodson Silberbauer-GottsbergerDötterl 1991; location of the inflorescences in the distance or under low light conditions (Gottsberger & aroids in the Neotropics, floral Kumano-Nomura &Yamaoka 2009). Inseveral pollin beetles arrived on inflorescence during all phases of anthesis (Kumano & Yamaoka 2006; constituents were 2-butanol, veratrole and found to be composed of 18 volatile organic compounds (VOCs), among which the main Acceptedthe arrival of Article 1969; Williams& Whitten 1999; Chartier Homalomena et al. Parastasia 2011a). Floral scent composition analyses have been so far restricted to a Homalomena is by far the most species-rich aroid genus in Indomalaya. Frequently, et al. scarabbeetles during the pistillate phase, while Colocasiomyia 2010; Hoe VOCs playan important role, indicating to pollinators the , recent studies revealed that many species of et al. spp.,including et al 2011a). . 2012; Pereira α in the wild. Field observations showed that that showed observations Field wild. the in -pinene. Floral-pinene. emission scent with was correlated mplexes grow sympatrically, often also flowering et al. et Parastasia Dercetina 2013), especially those with similar ation systems involving scarab beetles and et al.

et al. et (Scarabaeidae, Rutelinae) (Kumano (Kumano Rutelinae) (Scarabaeidae, et al. et 2011a). Nitidulid (Nitidulidae) and and H. propinqua M.Hotta (Mori & Okada 2001), 2014). Chemical analyses of 2010; Hoe Chaloenus Chaloenus ). Thefragrance was (Chrysomelidae, et al. Homalomena Homalomena 2011a), and chrysomelid et al. et are

This article is protected Allrights bycopyright. reserved. Tung Homalomena al. Borneensis (1),all belonging seven were among species selected study, three L.S.Tung & Y.C.Hoe, velutipedunculata study: Seven species representing three complexes of the section Studied species MATERIALS AND METHODS relationin tofloralscent emission during th mechanisms and pollination strategies, (2) floral wasset This study Sarawak wereinvestigated. the flowering biology and floral scent composit mesophytes or clumping herbs, also restricted to Borneo (Ng cu complex Borneensis The Borneo. to restricted ca comprises 10 species solitary distribution mesophytic herbs whoseis of acknowledged clumping herbs, the majority novel and mostly restricted to Borneo. The Giamensis complex S.Y.Wong & P.C.Boyce

Accepted Article 2013b). The Hanneae complex comprises at least 100 species of solitary mesophytes to et al. Homalomena debilicrista debilicrista Homalomena Previous publications (Kumano & Yamaoka 2006; Kumano-Nomura & Yamaoka 2009; 2010; Hoe species to to test species S.Y.Wong, Y.C.Hoe & P.C.Boyce (Hanneae complex); H. giamensis et al. al. et (Giamensis complex); 2011a) spurred further investigations to include alarger set of to the monophyletic section section monophyletic the to in situ Y.C.Hoe, L.S.Tung, S.Y.Wong & P.C.Boyce, and plant-pollinator interaction(s). Therefore, for the current H. gastrofructa H. gastrofructa e pistillate and staminate phases of anthesis. H. up to specificallycompare: (1) flowering cf. ions of (selected) species native to West scent compounds, and (3) pollinator behavior rrently has assignedfive species of solitary complexes: Hanneae (3), Giamensis (3), and borneensis

S.Y.Wong, Y.C.Hoe &P.C.Boyce, and Cyrtocladon Cyrtocladon Cyrtocladon et al. et Ridl. (Borneensis complex). All complex). (Borneensis Ridl. 2011). In the current study, (Ng (Ng H. matangae H. baangongensis were selected for the et al. 2011; Wong Y.C.Hoe,

et et H. October 2011 to June 2012. The total number of mature inflorescences within four day spans month from January 2010 until June 2012. However, we recorded flowering period only from Fieldwork at all the type localities wascarried out Phenology, flowering mechanisms, pollination strategies and insect visitors section). (local endemics, restricted population sizes), th forested edges of waterfalls, 120 – 150 masl. Ow growing on perhumid to moist evergreen forests, abundant along, but not restricted to, This article is protected Allrights bycopyright. reserved. syntopically with any other congeneric. Population of species are local, endemic to the type localities and small clumps of ca 20 – 25 plants. Individuals of of populations observed perhumid evergreen broadleaf forests on and adjacent to karst limestone, 35 – 50 m asl. The litter over limestone-derived loams on ridges and moderate slopes beneath lowland of Populations asl. About 25 individuals of areas along streams in a lowland moist to wet evergreen forest on karst limestone, 70 – 75 m intermixed with those of matangae scattered solitary individuals and colonies of 60 – 100 plants, whereas the population of forest trail margins, 250 – 375 m asl. The observed population of slopes in lowland tropical perhumid forest on red ultisols, often beside small streams and along al.

Accepted Article 2010; Hoe Populations of of Populations

was much smaller (ca 20 individual plants). Individuals of et al. et H. cf. 2011a&b; Wong borneensis H. debilicrista H. giamensis H. baangongensis, H. gastrofructa occurred intermixed with populations of occursyntopically with et al. et and 2013a; Fig. 1;Appendix 1; Supplementary Fig. 1). H. and 15 of 15of and occurringalong muddy trail margins and in shaded cf. cf. in Kuching Sarawak,Division, (Tung Malaysia e sizes were sample lowin study (see our next borneensis ing to the nature of the investigated species species investigated the of nature the to ing to identify flowering event(s) at least once a H. velutipedunculata H. baangongensis H. velutipedunculata

occurred as scattered individuals H. matangae H. debilicrista H. gastrofructa were observed. were did not occur H. giamensis ongentle to steep was ca 50 plants, comprised comprised grew indeep H. et et were: were: visitors was also documented. The number of inflorescences and plant individuals involved secretion were recorded. Throughout the entire events of spathe and spadix movement, floral scent emission, pollen extrusion and resin anthesis), and closing of the spathe limb (the en reduced floral odour (end of pistillate anthesis), pollen release (the onset of staminate andlimb of onset odour production(theof onset startfrom the untilend the ofanthesis,indicated respectively by theopeningspathe theof prior to anthesis. Observations on flowering me anthesis (Boyce &Wong 2008). undergo a complex series of seemingly coordinated spathe and spadix movements during matangae bearing spike – the spadix –subtended by a called the spathe. The spathe measures 6 – flower- anunbranched of iscomposed inflorescence erected Each synflorescence. maturing velutipedunculata gastrofructa substantially expanded with thecae dehiscing laterally. All Staminate have three to four (rarely five to six) stamens and connectives are staminodes). Ovariesare three- to four-locular naked and often accompanied bya staminode (hereafter referred to asinterpistillar zone, which are often separated by astaminode- The spadix equals the spathe in length and is divided into a lower pistillate and upper staminate 15 cm in length, has a weak to pronounced constriction between the lower and upper spathe. borneensis This article is protected Allrights bycopyright. reserved. Accepted Article was recorded during peak flowering season: H. debilicrista Inflorescences of the investigated taxa were All species of these complexes produce several inflorescences together in asequentially ; 1 , H.gastrofructa (4/2), (4/2), st –4 th (5/3). (5/3). Jan 2011 and 13 H. baangongensis (five inflorescences/three individual plants), ,

and H. giamensis th (2/1), – 16 – th H.giamensis May 2011 for

9 ;

th 1 , with each locule containing many ovules. st – 12 chanisms were carried out on an hourly basis d of anthesis). The phases of anthesis and the duration ofanthesis, the behaviorinsect of – 4 – bearing interstice. The pistillate flowers are pistillate anthesis), pistillate zone drying and identified and observed at least aweek th th Dec 2010 for Jan 2011 for (3/2),

H. velutipedunculata Homalomena H. H. matangae cf. cf. H. debilicrista H. baangongensis borneensis species studied so studied far species (2/1), (2/1), . (3/2), and and (3/2), and H. , H. H. cf. cf. H. 11 debilicrista for the total number of pistillate flower the ratio between the average for the total number of fruits per infructescence and the average pollinators (in pollinating the numerous flowers) in insects only. The net was removed at the end of the anthetic period. (2mmplastic net x2 mm mesh) prior to spathe allowingopening, selective accessto small This article is protected Allrights bycopyright. reserved. to check for adhered pollen grains. Further the most frequently observed inflorescence visi identifica for visitors insect obtain to anthesis ( ( ( chrysomelid beetles forscarab beetlesSchool) ( least family) were conducted by the authors and by K. Wada (Musashimurayama Daini Junior Museum. Voucher information for all taxa is provided in Appendix 1. and deposited at the Sarawak Forestry Herbar species. Allinflorescences, infructescences and insect visitors were preserved in 70% ethanol selected randomly from five infructescences (between three to five plant individuals) per plants. Seed set was estimated by counting the number of seeds on 10 developed fruits Inflorescences and infructescences of each species were randomly selected from different baangongensis inflorescences/five infructescences), Cycreon Colocasiomyia

Accepted Articleth April 2015 and 26 Fruit set of developing infructescences was used as ameasure of the effectiveness of An independent set of inflorescences was further bagged during the pistillate phase of Identifications of the anthophilous insects ). ). and (5/6), ), andA. G. Kirejtshuk H. giamensis H.giamensis Chaloenus th July 2015. Four inflorescences of each species were covered with a Parastasia were attained through net-treatment tests conducted between ), M. J. Toda (Hokkaido Univ (5/7), H. matangae (Russian Academy of Scienc ), H. Takizawa (Tokyo University of Agriculture) for s per inflorescence for each species: H. confirmation of the effective pollinators of cf. cf. tion. The body surfaces of specimens belonging to ium (SAR) and Sarawak Forestry Entomology Entomology SarawakForestry and (SAR) ium borneensis tors were examined under astereo microscope to lowest possibl the (5/5), (5/5), casesof successful visit, and wasdefined as

H. gastrofructa (6/6), and and (6/6), ersity) fordrosophilid flies es) for hydrophilid beetles H. velutipedunculata e taxonomic level(at (5/5), (5/5), H. debilicrista H. H. (5/5). (5/5). (six H. polymer (ORBO™ 402 Tenax through the bag. Floral VOCs were trapped in glass tubes containing 150 mg of an adsorbent clean needle (1 mm diam.), ca 10 perforations were made to the oven bags toallow airflow (GC-MS) ona Shimadzu GCMS-QP2010 Plus (Shimadzu Corporation, Kyoto, Japan), equipped fume hood. Analyses were conducted by combined gas chromatography-mass spectrometry 750 µL of the hexane eluate (see above). Each sample was then concentrated to 40 µL under a refrigerationanalysis. until (4 mL; with hexane eluted were traps inflorescences were covered with fine organdy bags to prevent insect visitation. The adsorbent simultaneously collected using an empty oven ba Spectrex, USA) through an air- vacuum pumps at aconstant flow rate of 200 ml per min (Spectrex PAS-500 Micro Air Sampler; This article is protected Allrights bycopyright. reserved. (2/2/2), phase infloresences/3 staminate phase inflorescences/3 plant individuals), Raguso &Pellmyr, 1998). The number of replicate samples were: Sampling offloral scents out forwas carried sixof the studied VOCs floral of analyses statistical and scent, chemical floral of Sampling baangongensis time) for the pistillate phase and between 05:00 h –09:00 h for the staminate phase of matangae oven bags (EasyRoastoven bags (January 2011 and January 2012). 2012), 2012),

Accepted Article cf. borneensis H. gastrofructa H. giamensis Prior to the analyses, 20 µL of tetradecane (internal standard, 13 ng/µL) was mixed with To obtain floral VOC samples, inflorescences H. velutipedunculata H. velutipedunculata (3/0/3). Floral VOCs were trapped for three hours between 05:00 h – 09:30 h (local (January 2011 and February 2012), ) intheir natural habitat using standard dynamic headspace methods (refer to (February and November 2011), TM (January, October and November 2011) and , Bacofoil, UK), from which scented airwas drawn by battery-operated ® 35-60 mesh, Sigma-Aldrich, USA). A control per sample was (5/5/5), drying silicagel tube (ORBO H. baangongensis H. baangongensis ≥ 98.5% purity; MERCK, Germany), then kept at -20 °C g. When sampling was not sampling wasnot g. When carriedout,being H. matangae were individually enclosed within PET film H. debilicrista (4/0/4),

TM 506; Sigma-Aldrich, USA). Using a Homalomena (January 2011 and January H. giamensis H. debilicrista (January 2011 and January H. velutipedunculata H. gastrofructa H. gastrofructa species (excluding (5/0/5) and and (5/0/5) (2 pistillate H.

H. Bray-Curtis distance index (Hammer (NMDS) was used to depict variations in floral scent composition among samples using the nece when performed were comparisons pairwise po and applied were permutations 9999 with tests 2001). To test for differences in floral scent profiles among species and phases, NP Manova performed with the Paleontological Statisti was used to determine the relative amount of each compound. peak areas on the chromatograms were integrated to obtain the total ion current signal, which Productivity ChemStationsoftware Agilent MSD TheKovats Retention Indexes (KIs) of the VOCs were obtained with an external standard (C from were taken spectra Mass respectively. of 100 psi. MS Source and quadrupole temperatures were set at 220 °C and 200 °C, 10 min (Kumano & Yamaoka 2006). The carrier gas flow was maintained at aconstant pressure This article is protected Allrights bycopyright. reserved. with a non-polar BPX-5 column (SGE Analytical Science; 30 m x 0.23 mm i.d., 0.25 spectral librariesspectral (MassFinder 4, NIST11 Wiley and 9 Registry™ referencing their mass spectra and retention ti ordination in the interpretation. rate of 5 °C min°C rate of5 temperature set to 200 °C. GC oventemperature was setat 35 °C for 5 min, then increased at a sample, 1 concentrated For each thickness). 8

Accepted Article-C 22 saturated alkanes, Supelco, USA). Compounds were tentatively identified by cross- All statistical analyses on floral VOCs co -1 to 180 °C, then at a rate of rate of 10 °C min et al. 2001). Stress values below 0.1 represent a good cs (PAST) software version 2.17 (Hammer m/z μ L mes with data from commercially available mass mpositional differences among samples were

was injected in splitless 35-500 in EI mode. (Agilent Technologies, Palo Alto, USA).The ssary. Anon-metric multidimensional scaling st-hoc tests with Bonferroni correction Bonferroni with for tests st-hoc

-1 th to 200 °C, to200 then steady heldfor Edition), integrated to the the to integrated Edition), mode with the injector injector the with mode μ m film et al. et

This article is protected Allrights bycopyright. reserved. inflorescences on 60 – 100 individual plants) together with during the peak season among the studied populations are as follows: peak season. The total numbers of mature infl the former always flowered more profusely than belonging to complexes Hanneae and Giamensis occurred syntopically, individuals belonging to taxa flowered profusely between December and January. When populations of species the only species with two flowering periods (November –January and April –June). All studied forallFlowering speciesofperiods studied the Phenology RESULTS ca 20individual plants), and monthly) brought by the North-East Monsoon (Fig. 2). Interestingly, which (April), February to (October) Accepted yielded ca 25 inflorescences among ca 50 individual plants. borneensis inflorescences; Bornee and Giamensis the belonging to species together with Article (10 inflorescences on ca 20 individual plants). Individuals of H. baangongensis H. giamensis H. gastrofructa H. gastrofructa (6 inflorescences on ca 25individual plants) together with (five inflorescences on ca 15 individual plants). Individuals of

corresponds to a period of intense rainfall (350 to 850 mm (ca 15 inflorescences on ca 25 individual plants) orescences observed within four day spans Homalomena nsis complexes exhibited similar number of those of the latter at any one time during the

H. matangae occurred mainly from November November mainly from occurred H. velutipedunculata H. debilicrista H. velutipedunculata (two inflorescences on (ca 30 H. was was cf.

stigmatic liquids secreted during the pistillate ph moved freely within the inflorescences or stayed inside the lower chambers. They fed on attractive to the flies than those of the remain between 06:30 – 06:45 h. Comparatively, the inflorescences of the field among the unbagged inflorescences. insects as effective pollinators. excluding not only self-pollinatio Inflorescences of average fruit set (> 81%), as well as high number of seeds per developed fruit: the spathe limb began to close acropetally. For into the lower chamber (Fig. 4h). On the third day, by 04:30 h, the inflorescence declined and Between 12:00 – 15:00 h, the spathe constriction was tightened enough to block the entrance individuals of the same time, pollen strings were extruded from inflorescences of all three species (Fig. 4c). In second floral scent emission event (lessintense th the staminate zone began to secrete amber-colored resin droplets (Fig. 4g). By 06:00 h, a inter-sexual phase. On the second day (staminate phase), as early as 02:30 h, the lower part of pistillate zone dried up and floral scent emissi This article is protected Allrights bycopyright. reserved. Accepted(83.3 ± 19.5), Articlecould be easily perceived by the human nose. By 17:00 h (or in 4b). Concomitantly, an intense aniseed odour limb opened widewith an inflated lowerspathe, allowing accessin the receptive pistils (Fig. pistillate phase of anthesis for allspecies started at ca03:00 h. By05:00 – 06:00 h, the spathe Anthesis lasted between 53 – 62 hrs in the three investigated species (Fig. 3; Fig. 4). The Hanneae complex Flowering mechanisms, pollination strategies and insect visitors Colocasiomyia H. gastrofructa H.

debilicrista H. debilicrista flies(Drosophilidae) arrived at the inflorescences of all three species , pollen wasmixedwith resin droplets to form a pale yellowpaste. (77.1 ± 11.7) and bagged with selective mesh (2 mm However, the first author observed infructescence developing in n and apomyxis, but also the role of small-sized anthophilous onindicated faded. This the beginningthe of emission, originated from the staminate zone, der species (Figs.4b, 4dder species H. velutipedunculata all three species, we recorded a very high ase, exudations from the inner surface of the an that of the pistillate phase) occurred. At

H. gastrofructa H. matangae Ø (80.4 ±14.7; Table 1). )yield didnotfruits/seeds, , 4i; Table 2). The fliesThe, 4i;Table2). were most most were , at 22:00 h), the H. debilicrista

part of the staminate zone were observed throughout the anthesis of and left at the end of the anthesis; Fig. 4l, Table debilicrista onset of the staminate phase. Staphylinid beetles were found inside one inflorescence of around 08:30 h (Table 2). Mating activities were observed and beetles left prior to or at the visiting inflorescences of belongingHanneae tothe complex. carried pollen attached to their bodies. day of anthesis, even though some stayed un consumption of stamens. The beetles left the inflorescences as early as 08:00 h on the second The feeding activity of the latter eventually led to damage of the staminate zone, due to heavy scarab and chrysomelid beetles remained unchanged until the massive release of pollen, when almost all individuals of both limb). Mating activities (Figs. 4b, 4h) were observed among the scarab beetles. The scenario also active on the upper parts of the spadix (staminate zone and inner surface of the spathe whereas the chrysomelid beetles, although more abundant inside the lower chamber, were flowers. During the pistillate phase, the scarab beetles remained inside the lower chamber, staminodes foundbetween the Immediately after arrival, both scarab and chrysomelid beetles were observed to consume the first (15 – 30 min earlier) and were observed Chrysomelidae, Galeuricinae Scarabaeidae, Rutelinae) (Figs.4b, under the microscope, pollen loads were not observed on their body surfaces. ( This article is protected Allrights bycopyright. reserved. activities were observed in inflorescences of spathe limb, the damaged stamens, and seemingly also on pollen. Mating and egg laying Accepted ArticleH. debilicrista, There were other intermittent insect visitors to the inflorescences of Between06:30– 08:30 h,scarab( beetles and two inflorescences of at 08:00 h; H. debilicrista H. gastofructa ) (Figs. 4f, 4j) arrived (Table 2). 2). arrived 4j) ) (Figs.4f, (Table

pistils, but only the latter moved onto the staminate zoneand 4d-e & 4h) and chrysomelid beetles ( Cycreon H. velutipedunculata and ,

at 16:00 h; and H. gastrofructa spp. (Coleoptera, Hydrophilidae) were found H. debilicrista to carry pollen onto the pistils (Fig. 4b). til the end of anthesis. Upon departure they 2). Mating and egg-laying activities at the lower Parastasia gestroi gestroi Parastasia

fed on those above the pistillate H. velutipedunculata, (arrivedat 06:45 h on the first day . during the pistillate phase, starting

The scarab beetles always arrived The flies and/or

left at the end of anthesis anthesis of end the at left consumed pollen (Fig. 4c). H. velutipedunculata Chaloenus P. nigripennis P. Homalomena at12:00 h) and, spp.; ; H. . A Giamensis complex was higher than those belonging to the Hanneae complex (Table 2). (Figs. 5c, 5d, 5f & 5i). The number of flies visiting inflorescences of species belonging to the Colocasiomyia Galeuricinae) wereobserved in inflorescences nigripennis of (72.8 ± 17.3), three investigated taxa(Table 1). Seed in species belonging to the Giamensis complex was spathe limb was fully closed and this marked the end of anthesis (Fig. 5l). The recorded fruit set – 08:0006:00the hby tightening spatthe of and but had the consistency of a paste in inflorescences of This article is protected Allrights bycopyright. reserved. from inflorescences of 07:00 – 10:00 h on the first day of anthesis (Figs. human nose between 06:00 – 07:00 h). The staminate zone secreted resin droplets between only one scent emission event during the pistilla similar to that described for species belongin following day, between– 04:00 03:00 hforall (Fig. 3;Fig. 5). The pistillate phase started at ca 03:00 h and the staminate phase on the Anthesis lasted ca30 hrs inall three investig Giamensis complex 4h, 4k). phaseagainandduring staminate phasesecondstofor 10 5 each timeto robpollen/resin(Figs. Table 2) visited the staminate zone of species of of stingless an unidentified individuals ( bee few

Accepted H. giamensis Article H. giamensis Colocasiomyia ; Scarabaeidae, Rutelinae) H. giamensis fliesarrived first, at ca 05:00 h, and most of them remained on the spathe limb did not yield fruits/seeds as previously described for at ca 07:00 h. The entrance into the lower chamber was blocked between flies(Drosophilidae), scarab beetles ( H. baangongensis (82.2 ± 17.2) and and chrysomelid beetles ( H. velutipedunculata set wasalso profuse inallspecies: onthe second day of anthesis at ca 06:00 h ated species belonging to the Giamensis complex Giamensis the belonging to species ated H. matangae he constriction. Between 09:00 – 09:30 h, the g to the Hanneae complex (see above), but with species. The flowering mechanism wasmostly of the three investigated species (Table 2). te phase (alemon-like fr 5b, 5h, & 5j). Pollen was extruded instrings also very high, recorded at over 91% for all H. matangae

(75.7 ± 13.9). Bagged inflorescences Trigona and Parastasia gestroi gestroi Parastasia Chaloenus H. debilicrista sp.; Apidae, Meliponini; atca 07:00 h (Figs. 5d, 5f) H. debilicrista agrance perceivable by spp.; Chrysomelidae, H. baangongensis during pistillate and P. .

(Fig. 5k), (Fig. 5k), S carab

This article is protected Allrights bycopyright. reserved. (Drosophilidae), tightened constriction around 06:00 h. By 09:00 h, the anthesis had ended. mixed with the resin to form a paste. The entrance to the pistillate zone was blocked by a phase. On the second day, between 04:00 – 06:00 h, pollen was extruded from the anthers and inflorescence declined slightly a found to excrete resin and was covered with it at ca 20:45 h (Fig. 6c). At the same time, the prominently perceivable between 06:00– 07:00 h). Later at ca 18:30 h, the staminate zone was one floral scent emission event during the pisti resembled that previously described for species belonging to the Giamensis complex, with only staminate phase on the following day, at ca 04 at the end of anthesis), whereas stingless bees ( inflorescences of insects present/active on inflorescences. Staphylinid beetles were observed inside belonging to found ininflorescences of all three species, but they were particularly abundant in those first day of anthesis and left at 06:30 – 07:15 when leaving the inflorescences. following morning. between 07:15 – 08:30 h on the first day of anthesis and left between 07:15 – 09:30 h on the left between 07:00 –07:45 h on beetles (Figs. 5c-e, 5g, 5h &5k) arrived between 06:30 –07:15 h on the first day of anthesis and AcceptedAnthesis lasted ca30 hrs for Borneensis complex described in associations involving species belonging to the Hanneae complex. phase (Table 2). The behavior of the insects and their activities were similar to what was Articleboth H. baangongensis Five insect taxa visited inflorescences taxa of visited Five insect H. baangongensis Parastasia H. matangae H. matangae Parastasia and

gestroi H. matangae H. and (Fig. 5g, Table 2). There were other intermittent anthophilous (visited at 10:00 h on the first dayof anthesis and left at 09:00 h cf. cf. nd the pistillate zone dried,indicating onset theinter-sexual of the following morning. Chrysomelid Cycreon borneensis (Scarabaeidae, Rutelinae) Chaloenus for 5 to 10 seconds at around 10:00 h during pistillate spp.(Hydrophilidae) arrived at 06:30 – 07:15 h on the beetles carried pollen attached to their bodies . The pistillate phase started at ca03:00 h and the h on the following morning. These beetles were :00 h (Fig. 3; Fig. 6). The flowering mechanism mechanism flowering (Fig.3;Fig. h The 6). :00 llate phase (an intense aniseed-like scent, most Trigona H. cf. cf. borneensis spp.) wereobserved with spp.) inassociation

, Chaloenus : Colocasiomyia Colocasiomyia

beetles arrived (Figs.5h-5j) spp. (Chrysomelidae, flies This article is protected Allrights bycopyright. reserved. Galeuricinae), compound classes originally proposed by Knudsen seven the of three to assigned and identified tentatively were VOCs 22 which of out complex, A total of 33 VOCs were isolated among all analyzed samples belonging to the Hanneae Hanneae complex Chemical composition of floral odour compounds 1). (Table borneensis speciesbelonging tothe HanneaeGiamenand speciesbelonging tothe HanneaeGiamensiand the insects and their activities were similar to in the bagged inflorescences for insect identifica remained on the inner spathe limb and left half an hour later. Staphylinid beetles were caught anthesis. Individuals of scarab and chrysomelid beetles left the inflorescences as early as 07:00 h on the second day of startedchrysomelid beetles show anthesis (ca09:00 h).Scarab beetles arrived at Most of the flies remained in the staminate zone and the spathe limb, leaving only at the end of Colocasiomyia 2-heptanol, and terpenoids (14) (Table 3). Out of these, large relative amounts (> 20%) of Accepted(0.96 – 55.06%), samp phase pistillate in found all of them were found in each of the analyzed samples (Table 3). Four monoterpenes were Article was very high very was α -pinene, sabinene, limonene and 2-ethylhexanol were detected, even though not fliesarrived first, at ca07:30 h, but were not confined to the pistillate zone. Cycreon β -pinene (1.04 – 44.22%), and myrcene (0.52 spp. (Hydrophilidae), and staphylinid beetles (Figs. 6b-6e & 6g, Table 2). Cycreon

(85.7%) and the number of seeds per developed fruit was 79.4 ± 15.1 les from all three species:les fromallthree spp. arrived on the second day of anthesis, atca 04:00 h. They ing up (they arrived until 17:30 h in one occasion). Both Both occasion). one hin 17:30 until arrived (they up ing what wasdescribed in associations involving sis complexes, average setfor the fruit ca 07:40 h and about fifteen minutes later, s complexes. As previously observed among tion during the pistillate phase. The behavior of et al. et (2006): aliphatics (7), benzenoids (2) α

-thujene (0.25 – 5.28%). The irregular terpenes – 10.55%), sec -butyl acetate, α -pinene H. cf. cf. significant differences in floral scent composition among them (F2,20 = 0.83, p =0.44). compounds occurring in lower relative amounts (Table 3). The NP-Manova test did not show 91.83%), with ( limonene, veratrole and were characterized by high percentages of pinenes ( pairwise comparisons p = 0.048). The floral scents Hanneae complex during the pistillate phase (F significant differences in the floral compou pistillate and staminate phases (NP-Manova tests, P>0.05). The NP-Manova tests showed For any single species, there was nosignifican (0.02 – 1.9%), limonene (0.26 – 11.74%), and veratrole (0.04 – 9.21%). 5.33%), dominant: were compounds Two 3). (Table (7) and terpenoids (2) benzenoids (5), aliphatics follows: of 26 VOCs during the pistillate phase of anthesis Inflorescences of the three species belonging to the Giamensis complex emitted an assortment Giamensis complex 6-methyl-5-hepten-2-one ( velutipedunculata staminate phase (F2.22 = 1.14, p species: velutipedunculata. were presentin pistilla only85.77%) This article is protected Allrights bycopyright. reserved. ( Z

Accepted Article )-4,8-dimethyl-1,3,7-nonatriene (0.14 – 9.46%) and( α sec -pinene (0.53 – 51.99%), sabinene (0.28 – 3.21%), sec -butyl acetate (0.16 – 91.33%), 2-heptanol (0.11 – 61.12%), -butyl acetate (2.89 – 96.98%) and ( Z )-4,8-dimethyl-1,3,7-nonatriene (1.41– 14.96%)and three unidentified is different from those of Nine compounds were found in staminate phase samples of allinvestigated sec H. gastrofructa -butyl-acetate (Table 3). = 0.36). In fact, the floral scent of the pistillate phase of te and staminate phase samples of ),whereas that of nds among all three species belonging to the H. debilicrista t difference in floral VOC composition between 2,27 = 3.8, p = 0.00 , of which14 were tentatively identified as E of pistillate phase inflorescences of the latter )-4,8-dimethyl-1,3,7-nonatriene (1.77 – α - and E )-4,8-dimethyl-1,3,7-nonatriene (0.46 –

and β β H. velutipedunculata -) and sabinene ( -pinene (0.20 – 19.06%), myrcene H. gastrofructa 3), but not3), during the α H. gastrofructa -thujene (0.01 – H. debilicrista (post-hoc (post-hoc was rich in in rich was and H. ) or ) or H. posterior research,posterior same in the association authors suggested that with observed for another pollinators of all the investigated taxa of Scarab beetles of the genus Effective pollinators and other anthophilous insects DISCUSSION 1,3,7-nonatriene (Table 3). three species belonging to the Hanneae complex, which in turn are rich in ( were compounds orThese absent ineither low only found relative insamples of amounts the by high percentages of pinenes ( phase floral scents of the three species belonging to the Giamensis complex were characterized This article is protected Allrights bycopyright. reserved. The NMDS representations of the floral scent composition of the studied Hanneae complex vs. Giamensis complex (Scarabaeidae, Dynastinae) (Mayo 1991; Maia associations involving plants of the Neotropical genus mitigated pollen paste. Utilization of resin for pollen adherence had also been observed in carried on their bodies onto the stigmas durin arenas inside asheltered floral chamber (Kumano-Nomura & Yamaoka 2009). Pollen was inflorescences, these scarabs secured food rewards, mating opportunities and safe mating Accepted Articlebetween the twocomplexes during the pi Giamensis complex – pistillate phase (Fig. 7). Flor (stress =0.13) showed two different group pa Homalomena Homalomena Parastasia α - and species studied by Kumano & Yamaoka (2006). In a (Scarabaeidae, Rutelinae) appear to be the primary β -), limonene, 2-heptanol, sabinene and veratrole. veratrole. and sabinene 2-heptanol, limonene, -), Homalomena stillate phase (F1,32 = 5.47, p = 10 tterns: Hanneae complex – pistillate phase and g the pistillate phase in the form of a resin- et al. et al VOCscompositions differed significantly 2010; Gottsberger . This is in accordance to what was what to isinaccordance . This

andcyclocephaline scarabs et al. Homalomena Homalomena E -4 2013). Two species )-4,8-dimethyl- ). The pistillate

species species (Toda &Lakim 2011; Fartyal and on the inner spathe, pollen, and also utilize the inflorescences as ovipositing chambers Table 2). investigated of species Homalomena the more reliable pollinators ( (2009) hypothesized that beetles of chrysomelid beetles, notably the appendix, are reported from other aroid taxa in Borneo and staminatestaminodes Suchflorets. (flora led to significant damage to the spadix due to blades (Darling 2007; Takizawa 2012). In our stud Adults mostly gather and feed on inflorescences, but have also been observed chewing on leaf described species (Takizawa 2013), most of which apparently closely associated with aroids. a with (Kumano congeneric study &Yamaoka 2006). genus so The far 41encompasses however, these beetles are only occasional po were observed allto visit investigated seven Philodendron diversity of The genus attraction of insects to the inflorescences of (Schismatoglottidae; Low P. nigripennis P. Borneo, with up to 5spp. inWest Borneo: This article is protected Allrights bycopyright. reserved. gestroi Parastasia of

Accepted Article Parastasia The anthophilous flies observed in inflor Chrysomelid beetles of the species the of beetles Chrysomelid Colocasiomyia nigricauda Colocasiomyia Homalomena Colocasiomyia Homalomena Homalomena were identified asinflorescence visitors of the investigated (ca650species) pollinated by Neotropi (Kuijten 1992). This species weretwo species species of and P. nigripennis (Sultana , which currently encompasses ca70 currently , which (ca 300 species) on Borneo, in cont et al. species,although unlikely,cannot bediscarded without furtherdata. et al. Parastasia 2014, 2015). When discussing the chemical cues involved in the et al. et 2013; Low Parastasia was previously documented in association with other C. schawalleri (Table 2). So far, 16 2002). The adults consume secretions on the stigmas scarabs) scarabs) even lowlevelsat of scent emission. Colocasiomyia P. burmeisteri Chaloenus schawalleri Chaloenus diversity islowascompared to the high species Homalomena Homalomena et al. et l) damages to the spadix by anthophilous llinators, something previously observed in a the consumption of interpistillar and interstice escences of five of the investigated y, their presence in the inflorescences often could eavesdrop on the eavesdroponthe same signals could by used 2015). Their role as pollinators of the cal Cyclocephalini (ca 500 species). ,

( Parastasia P. gestroi C. sp., Kumano-Nomura & Yamaoka (Table2).Unlike

nigricauda rast toits Neotropical sister taxa, species, isassociated to flowers (Chrysomelidae,Galerucinae) , spp. were recorded from P. moseri and Homalomena C. Parastasia , aff. P. moultoni P. heterodonta scarabs, taxa: , and , time in association with inflorescences of This article is protected Allrights bycopyright. reserved. belonging to the Giamensis complex are dominated by ( ‘packages’ that differed between the Hanneae and Giamensis complexes. The three species pollinators, however, their role comm.). Theirvisits were mostlyconfined to insect larvae present in the inflorescences (e.g., sites. Although the adults are phytophagous, th 2013). their relationships with aroid host of Araceae, Arecaceae and Magnoliaceae (Takenaka-Takano Accepted investigated scent samples the floral showed that spadixand movements, facilitated pollinatorentr the plant hosts are most likely olfactory. Floral Owing to the fact that pollinator attraction occu Floral odour as have been previously documented among other aroid taxa (Ramírez & Gómez 1978). the pistillate zone. It is also probable that they Trigona which have also been observed in the studied Bornean oviposition substrates (Pellmyr 1986; Takenaka-Takano Articleinflorescences, commonly used by several species as food source, mating sites and/or Adult hydrophilid beetles ( Staphylinid beetles (Staphylinidae) are known to visit fresh or decaying aroid spp.) aremost likely opportunistic pollen consumers, as they never ventured towards needs further investigation. s are species-specific (Takenaka Cycreon Homalomena spp.;Hydrophilidae) are recorded here for the first the pistillate zone and are disregarded as collect resin droplets as a nest building material, scent emission together with coordinated spathe spathe coordinated with together emission scent eir larvaeare predatory and may feed on other other beetles, flies) (A. G. Kirejtshuk pers. rred before dawn, long-range cues applied by ance during the pistillate phase. Analyses of Homalomena , which they appear to use as mating Homalomena et al. et E

)- and ( et al. et 2012; Low emitted specific floral VOC Z )-4,8-dimethyl-1,3,7- 2012). Withrareexceptions, et al. et . Stingless bees (Apidae, 2006; Fartyal et al. 2015), activities et al.

hosts (Gottsberger & Silberbauer-Gottsberger 1991; Maia evening, involving also floral scents aschemical Cyclocephalini (Scarabaeidae, Dynastinae). However, pollination occurs at dusk and early hepten-2-one species are differentiated by important secondary compounds (2-ethylhexanol and 6-methyl-5- blends of complex, but also exhibit amore variable ch complex are not only comprised by different VOCs than those found among the Hanneae Caladium bicolor Caladium attracted to the major constituents of aroid floral scents, such as 4-methyl-5-vinylthiazole in Different pollinators belonging to this species-rich et al. of exhibit an intermediate floral blend, combining compounds characteristic of the Giamensis ( This article is protected Allrights bycopyright. reserved. of the anthophilous species are quite similar (Jameson & Wada 2004). (Rutelinae) and Cyclocephalini (Dynastinae) are morphologically closely related, and the biology Homalomena mayalsoexis system communication efficient VOCs suffice to efficiently attr jasmonate in form Cyrtocladon Supergroup. butyl acetate) and Hanneae complexes ( nonatriene nigripennis Coincidently,

Accepted Homalomena Article 2013); 3,4-dimethoxystyrene, either alone or combined with ( selloum In the Neotropics, several aroid genera and in particular H. gastrofructa aloneand occur singly in its locality, with no other

and and (Dötterl (Dötterl sect. sect. Philodendron adamantinum Philodendron H. velutipedunculata vs sec (Wong (Wong sabinene and 2-heptanol; Table 3). (Maia -butyl acetate. Floral scents from species belonging to the Giamensis Cyrtocladon et al. et al. et al. and 2012); and dihydro- 2012); ( 2013b), arepollinatedscarab by beetles the of tribe H. debilicrista act cyclocephaline scarab pollinator andpollinator ruteline scarabs. Interestingly, the tribes Rutelini isthe only species invest S )-2-hydroxy-5-methyl-3-hexanone in α (Pereira - and - and are dominated by by dominated are emical composition among species. The floral t in the associations β tracks that guide the beetles to their floral β -pinene, 2-heptanol and limonene). -ionone, either alone orcombined with methyl tribe (ca 500 species) have been shown to be et al. Homalomena 2014). Hence, apparently one or two

et al. et igatedto bepollinated by Homalomena α 2010, Gottsberger - and Philodendron s, often specifically. Such an

involving speciesof velutipedunculata Z )-jasmone in )-jasmone β -pinene, but the two Taccarum ulei species from the from the species , the sister genus sister , the

Philodendron et al. appears to P. 2013). (Maia sec

- This article is protected Allrights bycopyright. reserved. by the main pollinators, The interpistillar staminodes of inflorescences of the investigated spp., Food, mating opportunities and safe mating arenas 2006). floral scent constituents of other species of aroids (Schwerdtfeger Pellmyr 2003). 2-heptanol, 2-ethylhexanol and 2-he spp., of pheromone scarab beetlespest ( Nomura &Yamaoka 2009). 2013). Kuanprasert of angiosperms (Knudsen Homalomena sabinene and reproductive success is exclusively dependent on associations with yucca moths ( from arid regions of North and Central America (Svensson concentrations in floral scents Lepidoptera, Tortricidae)(Knight 1997), also known as a component in attractants for the coddling moth ( 1994). ( only been reported once in floral scents ( of

Accepted ArticleHomalomena Peltandra Parategeticula Parastasia The monoterpenes E )-4,8-dimethyl-1,3,7-nonatriene is acommon herbivory-induced VOC (Azuma et al. et byKumano &Yamaoka (200 β

-myrcene were also detected in various species, such as virginica sp.,whichincluded 1998; Hadacek &Weber 2002; Schwerdtfeger scarabs, aswell as spp. and and Parastasia et al. et α sec -pinene, Sauromatum guttatum Sauromatum Prodoxus is more widelyrecognized in -Butyl acetate, a known component of the aggregation 2006). In Araceae, et al. et spp., and also by Strategus aloeus Strategus α Chaloenus β -pinene among the five dominant compounds (Kumano- 2011; Knight & Light 2012). Its presence in high -pinene and spp.; Lepidoptera, Prodoxidae) (Pellmyr & Huth 1994; Sauromatum guttatum Sauromatum 6) and are common in more than 50% of the families chrysomelids were attracted to the floral scent α β -pinene, -pinene, ptanone had all been previously isolated as (Patt , Scarabaeidae; Rochat -ocimene were also reported from another Chaloenus

et al. et al. Yucca β -pinene, linalool, camphene, spp.Apart from the interpistillar 1995; Skubatz 1995; 2006, 2011), whose , Araceae; Borg-Karlson et al. spp. (Agavaceae) populations Homalomena et al. 2002; Chartier 2002; Knudsen Anthurium Cydia pomonella et al. et al. et were consumed 2000), has Tegeticula spp., 1996; et al. et al. et al. et Arum et al. et ;

Spathicarpeae and Philodendreae (Maia a very common trait in many scarab-pollinated aroids, notably within the Caladieae, (Ng (Ng Thelower spathe is lengthier than the upper spathe in species belonging to the Giamensis and Borneensis complexes, but shorter in those belonging to the Hanneae complex chambers to accommodate more insects than species belonging to the Hanneae complex. belonging to the Borneensis and Giamensis complexes would provide more space in their lower (Wong pollinators the accommodate significance of this morphological character mi section temporary shelter for inflorescences soon after. Therefore, the lower chamber of pollen. Only then the beetles started to move upward to the staminate zone and leave the but the lower chamber was stilloccupied by progressed into the staminate phase of anthesis, the constricted spathe tightened back slightly, loosened to allow the insect visitors access to the lower floral chamber. As the anthesis which arein accordance to observation in Bröderbauer consumed by Cyclocephalini (Gonçalves &Maia 2006; Maia and This article is protected Allrights bycopyright. reserved. Accepted Articlespecies. Elsewhere in Araceae, this has been documented in Neotropical observation shared by Kumano & Yamaoka (2006) ina study with another staminodes, the interstice and staminate zone were also consumed by et al. Taccarum None of the Cyrtocladon 2011). The length of the lower spathe exceeding the upper spathe isapomorphic to Parastasia (Spathicarpeae), which are all pollinated by scarab beetles of the tribe , but showed a reversal in the Hanneae complex (Wong Homalomena Parastasia spp. and spp. until the onset of the staminate phase of anthesis. This is speciesinvestigated in this st Chaloenus Chaloenus et al. et et al. 2013b). Insuch a scenario, inflorescences of species Parastasia spp., and occasionally by 2010, 2013; Gibernau 2015). et al. ght be linked to providing sufficient space to 2013; Gibernau 2015). Pollen was also until just after the massive release of et al. et

Homalomena (2012). The spathe constriction udy trapped their insect visitors Trigona Chaloenus Chaloenus Dieffenbachia functions as a Homalomena et al. bees. 2013b). The spp., an

,

Gearum

This article is protected Allrights bycopyright. reserved. Scarab beetles of the genus CONCLUSIONS that both the pistillate and staminate phases of the investigated documented in Neotropical taxa sharing the same pollination strategy. One interesting point is compounds in high concentration, which could ensure pollinator discrimination as previously scents emitted during the pi protogyny, short anthesis (30 – 60 hrs), a sheltered floral chamber and strong attractive floral characters common in aroids associated with schawalleri pollinators of all the investigated AcceptedHaruo Matsuzawa, Alexander G.Kirejtshuk and Martin Fiká NCCD.907.4.4(Jld.12)-51 and Park Permit No. 121/2015. We sincerely thank Masanori J. Toda, acknowledged. The most recent fieldwork has been conducted under Research Permit No. (03). Thecollaboration and support of the Sa Vote No. ERGS/01(02)/808/2011(03), FRGS/STWN10(01)985/2013(26) and NRGS/1089/2013- This is part of an on-going research funded by the Ministry of Education of Malaysia through ACKNOWLEDGEMENTS Homalomena directed at the investigation of isolating ba related to the behavior of available specialized pollination strategies in the Old and New World scarabs are active at dusk and early evening. This could represent a divergence between during early morning hours, before or during sunrise, whereas in the Neotropics, cyclocephaline Article ) actingasaccessorypo , sincethey share the same set of pollinators.

Parastasia stillate stage. The floral scent blends contained uncommon Homalomena llen vectors/pollinators. ( P. gestroi rriers amongsyntopically these co-flowering rawak Forestry Department are gratefully large scarabsas specialized pollen vectors: pollen vectors. Future research should be taxa,withchrysomelid beetles ( tropics among closely related aroid taxa, likely and P. nigripennis P.

Homalomena č ek for identifying the insect Homalomena )

play the role of primary present pollination species occurred occurred species Chaloenus Chaloenus Dodson C.H.,Dressler R.L., H Darling C.D. (2007) Holey aroids: circular trenching behavior by aleaf beetle in Vietnam. Chartier M., Pélozuelo L., Buatois B., Bessière J-M., Gibernau M. (2013) Geographic variations of Boyce P.C., Croat T.B. (2013) [onward, continuously updated]. The Überlist of Araceae. Website Boyce P.C., WongS.Y. (2008) Studies on Homalomeneae (Araceae) of Borneo I: Four new Borg-Karlson A.-K., Englund F.O., Unelius C.R. This article is protected Allrights bycopyright. reserved. Accepted ArticleAzuma H., Thien L.B., Toyota M., Asakawa Y., Kawano S. (1997) Distribution and differential REFERENCES versions of the paper. specimens. We also thank the three anonymous reviewers for their comments on earlier compounds in orchid fragrances. fragrances. in orchid compounds Biotropica Arum odor and pollinators, and test for localadaptati 60 http://www.aroid.org/genera/ [accessed19th July 2013]. species and speculation and informspecies on released from Liriodendron expression of ( , 1–29. species (Araceae). species , 39 taxa. , 555–558. Sauromatum guttatum Sauromatum E )-4,8-Dimethyl-1,3,7-Nonatriene inleaf and floral volatiles of Journal of Chemical Ecology Chemical of Journal ills H.G.,AdamsR.M., Williams N. Functional Ecology, Functional Science al speciesgroup inSarawak. and , (1994) Dimethyl oligosulphides, major volatiles 164 Phallus impudicus Phallus

27 , 1243–1249. , , 1367–1381. on by reciprocal transplant of two European 23 , 2467–2478.

H. (1969) Biologically active . Phytochemistry Gardens' Bulletin Singapore Bulletin Gardens' , Magnolia 35 , 321–323. and , This article is protected Allrights bycopyright. reserved. Hoe Y.C., Wong S.Y., Boyce P.C., Wong M.H., Chan M.K.Y. (2011a) Studies on Homalomeneae D.A.T., (2001) PAST P.D. Ø.,Harper Ryan Hammer Hadacek F., Weber M. (2002) Club-shaped organs asadditional osmophores within the Fartyal R.S.,Gao J.J., Toda M.J., Dötterl S., David A., Boland W., Silberbauer-Gottsberger I., Gottsberger G. (2012) Evidence for Gibernau M. (2015) Pollination ecology oftwo AcceptedGottsberger G., Silberbauer-Gottsberger I., Dött Gottsberger G., Silberbauer-Gottsberger I. (1991) Olfactory and visual attraction of ArticleGonçalves E.G.,Maia A. (Araceae) of Borneo VII: VII: Borneo of (Araceae) for educationand dataanalysis. Biology Plant Sauromatum Araceae. behavioral attractiveness ofmethoxylated arom Systematic andEvolution Systematic differentiation in species of the Entomology species group having peculiar lifecycles on monsteroid (Araceae) host plants. Yin J.T. (2013) and observations of its pollination mechanics. (Araceae). (Araceae). emarginata Spathicarpeae). 38(EN2) , 38–66. Journal of Chemical Ecology Chemical Journal of Biotropica (Cyclocephalini, Dynastinae) to the inflorescences of , inflorescence: odor analysis, ultrastructural changes and pollination aspects. , 38 4 Colocasiomyia , 367–383. , 763–782. Aroideana C.D.(2006)evidence New ofpollinationin , 23 Homalomena , 23–28. , 299 , Hu Y.G., Takenaka-Takano K., Suwito A., Katoh T., Takigahira T., 29 (Diptera: Drosophilidae) revised phylogenetically, with a new , 793–809. , 148–151. Philodendron bipinnatifidum bipinnatifidum Philodendron Palaeontologia Electronica, Palaeontologia ,

38 debilicrista , 1539–1543. erl S.(2013) Pollinat Dieffenbachia Plant Diversity andEvolution Diversity Plant : Paleontological statistics softwarepackage atics in a dynastid scarab beetle-pollinated , a new species , anewspecies Borneo from Malaysian

in French Guiana. inFrench 4 complex (Araceae). (Araceae). complex , 9pp. Gearum brasiliense ion and floral scent Philodendron

, 129 Systematic Systematic

Erioscelis selloum , 77–87. Plant Plant Aroideana (Araceae: (Araceae:

,

Kumano Y., Yamaoka R. (2006) Synchronization between temporal variation in heat generation, Knudsen J.T., Eriksson R., Gershenzon J., Ståhl B. (2006) Diversity and distribution of floral scent. Knudsen J.T. (1999) Floral scent chemistry in geonomoid palms (Palmae: Geonomeae) and its Knight A.L., Light D.M. (2012) Monitoring codling moth (Lepidoptera: Tortricidae) insex Knight A.L., Light D.M., Trimble R.M. (2011) Identifying ( Kuijten P.J. (1992) Arevision of the genus Kuanprasert N., Kuehnle A.R., TangC.S. (1998) Floral fragrance compounds of some Jameson M.L., WadaK. (2004) Revision of the genus This article is protected Allrights bycopyright. reserved. Accepted Article Hoe Y.C., Wong S.Y., Boyce P.C., Wong M.H., Chan M.K.Y. (2011b) Studies on Homalomeneae propinqua floral scents and pollinator arrival in Garden importance in maintaining reproductive isolation. combination with codlem pheromone-treated orchards with ( Environmental Entomology formaleand acetic acidasanewfema lure Scarabaeidae: Rutelinae). Review Botanical (Araceae) species and hybrids. and hybrids. (Araceae) species Scarabaeidae: Dynastinae) from Southeastern Asia. Borneo. Borneo. (Araceae) of Borneo XI: , 83 Webbia: Journal of Plant and Geography and Taxonomy Plant of Journal Webbia: . , 141–168. Plant Species Biology Species Plant , 72 , 1–120. Homalomena matangae Homalomena one and acetic acid. Zoologische Verhandelingen Zoologische , 40 , 420–430. Phytochemistry , 21 , 173–183. the beetle-pollinated tropical Araceae, Parastasia E )-4,8-dimethyl-1,3,7-nonatrienepear esterin or Environmental Entomology , le codlingmoth (Lepidoptera: Tortricidae). 49 inthe Indo-Australian region (Coleoptera: , anew species , from Sarawak, Malaysian , 521–528. Memoirs of Memoirs the NewYork Botanical Zootaxa,

E , Peltonotus )-4,8-dimethyl-1,3,7-nonatriene plus 275 , 1–207. ,

502 66 , 143–148. , 1–66. Burmeister (Coleoptera: , 41 Homalomena , 407–414. Anthurium

Mori Y., Okada H. (2001) Reproductive biology and pollen flow of arheophytic aroid, Mayo S.J., Bogner J., Boyce P.C. (1997) Mayo S.J. (1991) A revision of Dötterl A.C.D., S., Maia Kaiser R.,Silberbauer-Go Maia A.C.D., Schlindwein A.C.D., Maia C.,Navarro D.M. Maia A.C.D., Gibernau M., Carvalho A.T., Gonçalves E.G., Schlindwein C. (2013) Low S.L., WongS.Y., Ooi I.H., Hesse M., Städler Y., Schönenberger J., Boyce P.C. (2016) Floral This article is protected Allrights bycopyright. reserved. Accepted ArticleLow S.L., WongS.Y., Boyce P.C. (2014) Kumano-Nomura Y., Yamaoka R. (2009) Beetle visitations, and associations with quantitative 37–47. sumatrensis London, UK: 370 pp. 46 Annonaceae and Araceae. the attraction ofscarab beetle pollinators: D.M.A.F., Schlindwein C., Gottsberger G. (2012) Thekey roleof4-methyl-5-vinylthiazole in species guarantees high fruit set. fruit high guarantees species acutatum (Araceae, Spathicarpeae). (Araceae, not makethe monk: scarabbeetle pollination of the Neotropical aroid Plant Biology Plant diversity and pollination strategies of thre and Evolution substantiated based on combined nuclear and plastid DNA sequences. variation of attractants in floral odors of Plant Research Plant , 601–681. (Araceae)in the Atlantic Forest of nort (Araceae) in the Ma in the (Araceae) , , 18 , 300 122 , 84–97. , 607–617. , 183–192. Philodendron Biological Journal of the Linnean Society, Linnean the of Journal Biological Journal of Chemical Ecology Chemical Journal of lesian wet tropics. International Journal of Plant Sciences, Plant of Journal International Schottarum The Genera of Araceae of Genera The A.F., Gibernau (2010)M. Pollination of subgenus Homalomena propinqua Homalomena e rheophytic Schismatoglottideae (Araceae). ttsberger I.,Teichert H., Gibernau M.,Navarro (Schismatoglottideae: Araceae) a unique olfactory floral signalsharedby heastern Brazil: asingle scarab beetle Meconostigma Plant Systematics andEvolution Systematics Plant

, 38 . Royal Botanic Gardens, Kew: Gardens, Botanic . Royal , 1072–1080. (Araceae). (Araceae). (Araceae). (Araceae).

108 Taccarum ulei ulei Taccarum Plant Systematics Systematics Plant , 22–34. 22–34. ,

171

The cowl does Kew Bulletin Journal of , 740–748. Philodendron Philodendron Furtadao Furtadao , 227 , , Patt J.M.,French J.C.,SchalC. Ramírez B.W., Gómez P.L.D. (1978) Production of nectar and gums by flowers of Raguso R.A., Pellmyr O. (1998) Dynamic headspace analysis of floral volatiles: a comparison of Pellmyr O.(1986) Function of olfactory and visual stimuli in pollination of Okada T. (1986) Estimation of the routes of synhospitalic distribution of the genus This article is protected Allrights bycopyright. reserved. AcceptedRochat D., Ramirez-Lucasa P., MalosseC., Aldana R., Kakul T., Morin J.-P. (2000) Role ofsolid- Pereira J., Schlindwein C., AntoniniY., MaiaA. Pellmyr O. (2003) Yuccas, yucca moths, and coevolution: areview. Pellmyr O., Huth C.J. (1994) Evolutionary stab Article Ng K.K., Sofiman O., Boyce P.C., WongS.Y. (2011) Studies on Homalomeneae (Araceae) of Peltandra virginica Peltandra deliciosa methods. americanum Indonesia. Duda (Diptera, Drosophilidae) with descriptions of three new species from Malaysia and phase microextraction inthe identification Trigona Society Linnean scarab pollinator with specific do Oliveira R. (2014) Gardens Botanical moths. Homalomena suprageneric informal Sundaic for taxa of additional Delimitation VIII: Borneo Nature bees. ( Oikos Araceae Proceedings of the Japanese Society of Systematic Zoology of Systematic Society Japanese the of Proceedings (Araceae) by aStaphylinid beetle . Brenesia , Webbia , , 372 111 81 , ) and of some species of of somespecies of ) and (Araceae). (Araceae). , 238–254. 90 , 257–260. Philodendron adamantinum adamantinum Philodendron , 679–691. , 35–55. , , 66 14/15 , Lech J.,Hartman T.G. (1995) The pollination biology of Tuckahoe, , 21–28. , 407–412. American Journal of Botany Journalof American minant floral scent volatiles. ility of mutualisms be C.D., Dötterl S., Martin . Madrono Clusia ofhighlyvolatile pheromones oftwo (Araceae) lures its si its (Araceae) lures

( Guttiferae ,

33 , 82 , 47–54 , 1230–1240. Annals of the Missouri Missouri the of Annals tween yuccas and yucca and tween yuccas ) collected by New World New by ) collected Biological Journal of the of Journal Biological . s NavarroD.M.A.F., C., , Lysichiton Lysichiton 33 ngle cyclocephaline , 32–39. Drosophilella Monstera

This article is protected Allrights bycopyright. reserved. Schwerdtfeger M., Gerlach G., KaiserR. (2002) Anthecology in the Neotropical genus Takenaka-Takano K., Repin, R., Mohamed M.D., Toda M.J. (2012) Pollination mutualism Svensson G.P., Pellmyr O., Raguso R.A. (2011) Pollinator attraction to volatiles from virgin and Sultana F., Hu Y.-G., Toda M.J., Takenaka K., Yafuso M. (2006) Phylogeny and classification of Sultana F., Toda M.J., Yafuso M., Lakim M.B., Mohamed M.Bt., Cuong N.M. (2002) A new AcceptedSvensson G.P., Pellmyr O., Raguso R.A. (2006) Strong conservation of floral scent composition in ArticleSkubatz H., Kunkel D.D., Howald W.N., Trenkle R., Mookherjee B. (1996) The 564. Colocasiomyia Dynastinae). Rhinoceros beetles between new species of the genus 1583.Takenaka K.,Yin J-T., WenS-Y., Toda pollinated host flowers in ayucca/moth obligate mutualism. aroid plants. Colocasiomyia Science descriptions of two new species from Eastern Malaysia and Vietnam. genus species-group of the colocasiifolia two allopatric yuccas. attractiveness to insects. guttatum report. preliminary A (Araceae): , 5 Alocasia macrorrhizos Alocasia appendix as an osmophore: excretory pathways, composition of volatiles and , 305–315. (Araceae)in Yunnan, China. Systematic Entomology Journal of Chromatography A Chromatography Journal of species (Diptera: Drosophilidae) in Sabah, Borneo. (Diptera, Drosophilidae), and its evolution of pollination mutualism with Scapanes australis Scapanes Journal of Chemical Ecology Chemical of Journal New Phytologist New Colocasiomyia Colocasiomyia (Araceae) and two taxonomically undescribed Selbyana , 31 and deMeijere (Diptera: Drosophilidae) and , 684–702. , Entomological Science , deMeijere (Diptera, Drosophilidae), with , M.J. (2006) Pollination mutualism between a 23 134 885 , 258–267. Strategus aloeus Strategus , 631–640. , 433–444. , 32

, 2657 – 2665. Oikos (Coleoptera,Scarabaeidae, , 9 Plant Biology Plant , 79–91. , 120 Entomological , 1577– Sauromatum Sauromatum , 14 Anthurium Steudnera , 555–

Wong S.Y., Meerow A., Croat T.B. (2016) Resurrection and new species of the Neotropical genus Wong S.Y., Tan P.J., Ng K.K., Ahmad Sofiman O., Lee H.B., Fasihuddin Badruddin A., Boyce P.C. Wong S.Y., Hoe Y.C., Tung L.S., Boyce P.C. (2013a) Studies on Homalomeneae (Araceae) of Williams N.H.,Whitten W.M. ( Tung L.S., Wong S.Y., Boyce P.C. (2010) Studies on Homalomeneae (Araceae) ofBorneo VI: This article is protected Allrights bycopyright. reserved. Takizawa H. (2012) Description of new species of the genus Accepted ArticleToda M.J., Lakim M.B. (2011) Genus Takizawa H. (2013) Five new species of the genus Adelonema morphological and chemical data. (2013b) Phylogeny of Asian Borneo XIII – New species of XIII– Newspecies of Borneo Biology euglossine bee-pollinated orchids: A study of pollination. giamensis Homalomena Science Malaysia: High species diversity and use of host aroid inflorescences. (Chrysomelidae, Alticinae). Alticinae). (Chrysomelidae, Sunda Islands (Coleoptera: Chrysomelidae: Alticinae). , , 14 14 , 129–136. , 262–270. (Araceae: Philodendron Clade). Aroideana , 33 , anewspecies from Sarawak, Borneo, Malaysian with notes on its 1999) Molecular phylogeny and floral fragrances of male , 201–211. Japanese Journal of Systematic Entomology Systematic Journalof Japanese Homalomena Homalomena Colocasiomyia Systematic Botany Systematic (Araceae) based on ITS region combined with with combined ITS region on based (Araceae) . Aroideana Systematic Botany Systematic Chaloenus Stanhopea (Drosophilidae: Diptera) inSabah, Bornean

, , Genus 38 36 Chaloenus Westwood from Sabah, Malaysia (Orchidaceae). , 589–599. , 8–29. , 23 , 41 , 269–330. Westwood from Greater , in press. press. , in Entomological , Plant Species Species Plant 19 , 35–46. complex. complex. Hgiam present in only four of the analyzed samples. present inonly two ofthe analyzed samples; complex. complex. in the course of the pistillate ( were obtained by dynamic headspace during the interval of highest perceivable scent emission scents floral sixspeciesof of Table 3. roman letter represents syntopic taxa. Malaysia. Numerics (-/-) represent number of replicates/number of individual plants. The same per inflorescence of seven Table 2. This article is protected Allrights bycopyright. reserved. Table 1. Captions 0.5% ofthe total amount inany sample. compound class and Kovats retention index (RI). Unknowns were included when present with > individual plants. tr, trace amounts (< 0. debilicrista Accepted ArticleSa Kuching Division, forinvestigated species fruits selected randomly from five infructescences (between three to five plant individuals) per developed fruits per infructescence, percentage of fruit set and seeds based on 10 developed ( Identified species and number of insect taxa (mean ± standard deviation and range) Mean number ± standard deviation (SD) Chemical composition (mean and/or range of relative amounts of each VOC) of the H. giamensis H. BC BC ), represents Borneensis complex. represents Borneensis complex. n represents number of replicates. Hgast ( rawak, Malaysia. rawak, Malaysia. H. gastrofructa ), Hmata Hmata Homalomena Homalomena Homalomena ( ♀♂ H. matangae n tmnt ) phases of anthesis. ) and staminate ( ), HC (Araceae) under natural environmental conditions in Hvelu HC represents Hanneae complex. speciesatfour localities in represents Hanneae complex. (Araceae) belonging (Araceae) to section ( a present in only one of the analyzed samples; H. velutipedunculata 01%). The compounds are listed according to according arelisted compounds The 01%). c ). *represents number of replicates/number of present in only three ofthe analyzed samples; of pistillate flowersperinflorescence,

), Kuching Division, Sarawak, Hbaan GC GC representsGiamensis represents Giamensis Cyrtocladon ( Hdebi H. baangongensis ( Homalomena Homalomena . Samples . Samples ), d b

G-I &K-L. pollen. L. Staphylinid beetles are present during staminate stage. A-F. chamber during pistillate stage. J. post-pistillate stage. F.Spathe arti This article is protected Allrights bycopyright. reserved. staminate stage. present. G. Onset of staminate consuming pollen. D. Pistillate stage. stage, black arrow shows pollen being carried in by the beetle. C. insects and their activities. A.Onset of pistillate stage. B.Apair of Fig. 4. complexes, respectively. baangongensis Fig. 2. 7. complex). (Hanneae giamensis 2. complex). Fig. 1. AcceptedFig. 3. Article Malaysia. Kuching airport station (01°29'N, 110°20'E), Sarawak Division, Meteorology Department complex(HC); Giamensis (GC);Borneensis complex syntopic, co-flowering taxa have the same shade color. Species belonging to Hanneae complex Flowering period of the seven Localities of seventhe Flowering at different stages inspecies of the Hanneae complex together with visiting Flowering mechanism and presence of insect visitors for (Giamensiscomplex).5. Homalomena velutipedunculata Homalomena H. debilicrista , and Parastasia H. cf. H. baangongensis borneensis (Hanneae complex). 3. 3. complex). (Hanneae mating.Black arrow shows Homalomena stage. secretion. Blackarrow resin shows of the end H. At ficially removed. Staminate stage. Chaloenus schawalleri Chaloenus H. representing the Hanneae, Giamensis, and Borneensis Homalomena cf. cf. Parastasia borneensis (Giamensiscomplex). . J. species studied. 1. studied. species Homalomena gastrofructa Homalomena and H. matangae species studied. Note horizontal bars of (BC). Data Data on(BC). rainfall (mm) isprovided by (Borneensis complex). 6. (Borneensis Colocasiomyia Trigona ,

Chaloenus Chaloenus H. velutipedunculata (Giamensis complex). 4. sp. I. sp. Homalomena debilicrista Chaloenus schawalleri Chaloenus Parastasia are present. E. spp. K. Chaloenus schawalleri Chaloenus Colocasiomyia Homalomena debilicrista . Trigona during pistillate H. gastrofructa Parastasia (Hanneae sp. robbing atthe lower

H. , H. is

at . voucher, and GenBank accession number Appendix 1. corresponds to a particular complex species at a particular anthesis phases. profiles of sixinvestigated Fig. 7. borneensis. Parastasia Parastasia insects and their activities. A& B. At pistillate stage. C & D. Prior to staminate stage with Fig. 6. baangongensis of anthesis. A. the staminate zone. J. staminate stage with schawalleri present. E. This article is protected Allrights bycopyright. reserved. Accepted Articlestage.D. Massive pollen extrusionwith prior to the staminate stage. C. pistillate stage; 3: one day after anthesis; 4: thre visiting insects and their activities. 1-4 indicating Fig. 5. Non-metric multidimensional scaling (NMDS) representation of the inflorescence scent Flowering at different stages inspecies of the Borneensis complex together with visiting A. Flowering at different stages in species of the Giamensis complex together with copulating during bagging for floral odour trapping. A-G. present. E. At staminate stage with and Parastasia

List of specimens investigated: Taxon, Homalomena giamensis Homalomena . Colocasiomyia Chaloenus carryinginterpistillar staminode. Chaloenus Chaloenus Homalomena . G.Atpistillate stage with Parastasia and sp. and Parastasia . B-F. . B-F. Parastasia species (stress value= (stress 0.13). Each species colour plot different C. schawalleri . Taxaare arranged alphabetically. and Homalomena matangae Homalomena Parastasia Colocasiomyia . Note the resin secretion and the damage on e days after anthesis). B& C. Resinpresent just the flowering sequence (1: emerging bud; 2: at , collection locality, geographic coordinate, coordinate, geographic locality, collection Chaloenus schawalleri Chaloenus . K. F.At staminate stage with

present. F. End of anthesis. G. Cycreon Parastasia arepresent during pistillate and Homalomena . G-L. . G-L. consuming pollen. L. End Parastasia and Homalomena Homalomena Colocasiomyia . H & I. Prior to cf. cf. Chaloenus Chaloenus

Table 1. Homalomena intermixingly with H. baangongensis H. H. matangae H. matangae H. giamensis H. giamensis complex. complex. This article is protected Allrights bycopyright. reserved. H. gastrofructa H. debilicrista Number Sa Kuching Division, forinvestigated species fruits selected randomly from five infructescences (between three to five plant individuals) per developed fruits per infructescence, percentage of fruit set and seeds based on 10 developed of and inflorescences. A. Supplementary Fig. 1. H. velutipedunculata H. velutipedunculata

Acceptedcf. Article borneensis Mean number ± standard deviation (SD) BC represents Borneensis complex. n represents number of replicates. GC GC GC cf. HC 2. 20(=) 0. 19(=) 32 82.2 ± 17.2 93.2 207.4 ± 31.9 (n=7) 222.6 ± 12.0 (n=5) HC

borneensis. borneensis. BC 3. 37(=) 8. 81(=) 11 77.1 ± 11.7 81.1 189.2 ± 18.1 (n=5) 233.4 ± 33.7 (n=5) GC

Homalomena rawak, Malaysia. rawak, Malaysia. 9. . n5 170±3. n6 9. 72.8 ± 17.3 91.9 147.0 ± 31.0 (n=6) 297.4 ± 4.2 (n=5) HC Homalomena velu Homalomena Flowering populations with white arrows showing the emerging buds 9. 78(=) 7. 55(=) 34 80.4 ± 14.7 93.4 178.4 ± 25.5 (n=5) 191.0 ± 37.8 (n=5) Homalomena 3. 41(=) 1. 54(=) 57 79.4 ± 15.1 85.7 116.7 ± 15.4 (n=6) 136.2 ± 14.1 (n=6) 2. . n5 278±1. n5 9. 75.7 ± 13.9 91.1 207.8 ± 13.6 (n=5) 228.0 ± 9.3 (n=5) 83.3 ± 19.5 85.8 203.4 ± 39.5 (n=5) 237.0 ± 26.9 (n=6) per inflorescence pistillate flowers cf. cf. borneensis borneensis HC (Araceae) under natural environmental conditions in represents Hanneae complex. tipedunculata.

(2) Developed fruits per infructescence of pistillate flowersperinflorescence, . C. Homalomena gastrofructa. Homalomena B.

Homalomena giamensis giamensis Homalomena GC Fruit set set Fruit (%) (%) representsGiamensis

D. Seeds per fruit (1) growing (1) growing complex. complex.

This article is protected Allrights bycopyright. reserved. roman letter represents syntopic taxa. Malaysia. Numerics (-/-) represent number of replicates/number of individual plants. The same per inflorescence of seven Table 2. HC HC H. gastrofructa H. debilicrista Plant taxa H. baangongensis 6/4, HC H. velutipedunculata ii, GC

Accepted Article

Identified species and number of insect taxa (mean ± standard deviation and range) BC represents Borneensis complex.

3/3 6/4 ,

, i 4/2

, ii , , 1 –3 1.8 ± 0.8 P. nigripennis gestroi P. 1 –3 ±2.0 1.0 P. nigripennis gestroi P. 2.0 ± 0.8 gestroi P. spp. Parastasia 1 –2 1.3 ± 0.5 P. nigripennis Homalomena +

+

1 –13 5.8 ± 5.5 2 sp. + 1 sp. schawalleri C. 7 –12 9.0 ± 2.7 schawalleri C. schawalleri C. spp. Chaloenus 1 –30 7.5 ± 11.4 schawalleri C.

HC speciesatfour localities in represents Hanneae complex.

+

level to species Unidentified 10 – 25 15.0 ±6.0 heterodonta + C. nigricauda 14 – 70 34.7 ±30.8 42.5 ±18.7 heterodonta + C. nigricauda a Colocasiomyi 5 –36 13.5 ±12.8 C. nigricauda spp. C. C. Flower visitor taxa visitorFlower aff. aff. aff. aff.

level to species Unidentified 1 –6 2.7 ± 2.0 level to species Unidentified 0 –5 2.3 ± 2.5 30.5 ±13.2 level to species Unidentified Cycreon sp. 1 0 Kuching Division, Sarawak, spp. GC represents Giamensis sp. 1 0 0 –16 6.0 ± 8.7 0 Unidentified spp. Staphylinidae 3 –48 20.2 ±19.5 0 –3 ±1.0 1.7 level to species Unidentified 1.8 ± 0.5 level to species Trigona 1 –3 1.7 ± 0.8 level to species Unidentified spp. This article is protected Allrights bycopyright. reserved. GC iii, BC H. H. matangae H. giamensis

Acceptedcf. Article

borneensis (5/4)

4/3 , iii (3/3)

i , , GC

1 –10 4.7 ± 4.7 gestroi P. 1 –9 6.3 ± 3.6 P. nigripennis gestroi P. 1 –6 2.8 ± 1.9 gestroi P. 1 –3

+

1 –3 2.3 ± 1.15 level to species Unidentified 0 –5 2.8 ± 2.2 schawalleri C. 6.3 ± 2.2 1 –14 4.8 ± 5.3 schawalleri C. 4 –9 30 – 59 41.0 ±15.7 heterodonta + C. nigricauda 29 – 66 45.3 ±17.0 heterodonta + C. nigricauda 30 – 85 57.0 ±20.5 heterodonta + C. nigricauda 15 – 55

C. C. C. aff. aff. aff. aff. aff. aff.

1 –3 2.0 ± 1.0 level to species Unidentified 4 –17 11.0 ±5.5 level to species Unidentified 2 –6 4.4 ± 1.5 level to species Unidentified 1–2 22 – 50 0 –7 2.3 ± 4.0 sp. 1 0 0 –16 6.6 ± 5.9 2 sp. + 1 sp. 0 1 –2 1.4 ± 0.6 level to species Unidentified in the course of the pistillate ( were obtained by dynamic headspace during the interval of highest perceivable scent emission present in only one of the analysed samples; present in only three of the analysed samples;

This article is protected Allrights bycopyright. reserved. scentsfloral ofsixspecies of Table 3. ( debilicrista Unknowns were included when present with > 0.5% of the total amount in any sample. (RI). index Kovats retention classand compound to according listed are compounds The 0.01%). matangae Homalomena baangongensis Homalomena 1 Aliphatics Average scent emission (µg·h Total number ofcompounds 110,67,41,95,43 Esters Alcohols Accepted) Article sec unknown 2-nonanol 2-ethylhexanol 2-heptanol 1-hexanol -butyl acetate acetate -butyl Chemical composition (mean and/or range of relative amounts of each VOC) of the m/z ).*represents number ofreplicates/number ofindividualplants. amountstr, trace (< ), : Hgast ( H. gastrofructa - 1106 1031 907 871

(RI) index on Retenti < 800 1285 Homalomena ), ♀♂ ) and staminate ( ) phases of anthesis. of anthesis. ) phases ) and ( staminate ------14.06 --- 116.9 9 2/2* Hdebi Hgiam ), a

♀ Hvelu

( Homalomena giamensis Homalomena (16.75 – 52.45 ------61.12) (0.11 – 30.61 --- 196.4 11 3/2* Hdebi ( (Araceae) belonging to section b b Homalomena velutipedunculata Homalomena

♂ b

present in only two of the analysed samples; d present in only four of the analysed samples. 0.55 2.39 --- 46.84 --- 0.37 127.7 21 2/2* Hgast Hanneae a a a

a

♀

complex

0.16 1.98 --- 0.12 33.62) (1.24 – 17.43 --- 497.3 20 2/2* Hgast a a a

♂

), Hmata Hmata (31.95 – 32.74 --- 0.60 --- 22.15) (10.69 – 14.63 --- 323.7 18 5/3* Hvelu a c

♀ Hdebi

( Homalomena Homalomena Cyrtocladon (1.87 – 68.45 ------0.18 ------22.38) (2.73 – 7.46 tr --- 10 295.1 963.9 1,058.5 1,649.0 12 19 20 5/3* Hvelu ), ( Homalomena Homalomena Hbaan d

♂

0.79) (0.23 – (24.21 – 60.55 0.47 0.03 ♀ Hbaan a

0.06 4/3* 4/3* . Samples . Samples a c a ------a

Giamensis

------(2.89 – 5.27 ♀ Hgiam c

4/3* 4/3* a complex

(8.64 – 14.31 --- 3/3* ♀ Hmata

This article is protected Allrights bycopyright. reserved. Terpenes Aromatics 57,43,41,71,98 AcceptedMonoterpenes Ketones Ethers ArticleEsters Ketones camphene camphene β α α unknown veratrole methyl salicylate benzoate methyl 6-methyl-5-hepten-2-one 2-heptanone -citronellene -citronellene -pinene -pinene -thujene m/z : 952 937 1156 1210 1106 991 895

934 927 1112 (0.40 – 0.57 --- 55.06) (41.49 – 48.27 5.65 2.96 ------a a

------15.27 88.15) ------7.85) (1.72 – 4.44 0.62) (0.01 – 0.24 --- 1.97 a

a

------18.58) (16.22 – 18.58 ------3.76 26.75 3.36 --- 5.49 a a a

a

------8.34 0.80 5.34) (0.08 – 2.71 ------18.02) (3.36 – 10.69 51.99) (12.60 – 32.30 5.33) (1.57 – 3.45 --- 9.21 a a a

------2.12) (1.33 – 1.65 33.65) ------13.60) (0.96 – 6.07 10.55) (0.25 – 2.78 --- 26.33) (2.79 – 12.33 c ------0.24 ------18.61) 10.10) 91.33) 96.98) ------23.22) (0.53 – 5.46 3.3) (0.34 – 1.14 ------0.39) (0.04 – 0.27 d c

0.24) (0.22 – 2.94) (0.07 – 0.23 ------0.08 1.29 b a c ------0.31 0.02 a a a ------0.055 0.06) (0.05 – b This article is protected Allrights bycopyright. reserved. nonatriene nonatriene 107,69,79,41,91 43,67,41,109,105 Accepted terpenes Irregular Article ( ( unknown linalool ( ( limonene unknown α myrcene β sabinene E Z E Z -pinene -pinene -phellandrene -phellandrene )- )-4,8-dimethyl-1,3,7- )-4,8-dimethyl-1,3,7- )- β β -ocimene -ocimene m/z m/z : : 1105 1034 992 980 975

1130 1099 1082 1050 1040 1013 1011 0.74) ------5.43) (2.16 - 3.80 ------0.61) (0.52 – 0.56 28.67) (2.29 – 15.48 36.30) (3.67 – 19.98

------0.31 0.84) (0.02 – 0.32 3.58) (0.20 – 1.61 0.91) (0.82 – 0.86 (8.18 – 43.14 2.73) (0.86 – 1.79 ------3.22) (0.26 - 1.62 a b b b 0.34 --- 5.28 44.22 --- 4.76 7.58 4.51 ------a a a a a

a

------1.9) (0.12 – 1.01 17.13) (9.36 – 13.25 2.44) (1.05 – 1.74 0.46 0.32 0.07 ------0.22 9.87) (1.75 - 5.81 a a a a

------1.42) (0.76 – 1.13 10.08) (1.04 – 4.48 2.18) (0.16 – 0.88 (3.08 - (3.08 - 6.25 0.26 --- 1.05) (0.93 - 0.99 0.92) (0.83 - 0.88 2.84) (0.03 - 0.97 44.24) (4.41 - 28.18 d a b c b

------0.96 --- 0.99) (0.15 – 0.34 19.06) (0.44 – 4.46 3.21) (0.28 – 1.06 (1.58 - (1.58 - 19.59 9.46) (0.14 - 3.17 ------1.1 ------0.58 --- 11.74) (0.91 - 3.23

d d

0.05) (0.02 - (1.77 - (1.77 - 3.06) (1.84 - 1.29) (0.27 - 0.035 ------46.16 2.45 0.65 0.1 --- b c b c 86.29 5.96 1.17 ------(81.58 - (81.58 - 14.96) (1.41 - 2.34) (0.57 - a a ------d d a a ------d 81.32 2.85 0.68 (77.81 - (77.81 - 4.17) (2.17 - 0.79) (0.61 - --- c c c This article is protected Allrights bycopyright. reserved. Unidentified compounds Accepted43,79,57,69,93 83,55,69,84,41 83,55,69,41,53 43,79,93,94,71 43,79,41,93,94 79,43,41,71,59 Article57,85,41,43,55,81 57,43,41,69,67 101,98,55,43,83 41,71,58 43,45,41,57,58 unknown unknown unknown unknown unknown unknown unknown unknown unknown unknown unknown m/z m/z m/z m/z m/z m/z m/z m/z m/z m/z m/z : : : : : : : : : : 57,43, :

1407 1285 1282 1238 1234 1225 1214 1187 1178 1112 961 ------2.96 --- a

------78.11) ------1.13 0.16 0.25 ------0.76 ------0.68 a a a a a

------1.59 ------a

------0.08 11.87) 5.86) (0.57 - 3.21 ------a b

------0.23 --- 0.15 ------1.20) (0.05 - 0.62 85.94) 91.83) 85.77) 71.35) ------0.04 ------0.97 ------0.18 ------0.31 b 2.68) (0.15 - 0.45) (0.31 - 1.41 ------0.38 b a a b a 0.16 0.9 0.07 ------0.33 tr a

a

a a a a a a ------0.04 0.15 0.12) (0.02 - 0.29) (0.02 - 0.06) (0.04 - 0.07 0.05 c c b b

This article is protected Allrights bycopyright. reserved. AcceptedAverage monthly precipitaon (mm) Article 150 300 450 600 750 900 H. baangongensis H. gastrofructa c o Dec Nov Oct H. velupedunculata H. H. debilicrista (HC) sp.cf. (GC) 012012 2011

borneensis (HC) H. matangeae H. giamensis (HC)

(BC) (GC) (GC) a e a p a Jun May Apr Mar Feb Jan

This article is protected Allrights bycopyright. reserved. 03h00 03h00 Accepted Article03h00 ≈ ≈ ≈ 06h00 06h00 06h00 ≈ ≈ ≈ 09h00 09h00 09h00 12h00 12h00 12h00 a Day 2 Day 1 15h00 15h00 15h00 18h00 18h00 18h00  21h00 21h00 21h00 00h00 00h00 00h00  03h00 03h00 03h00 06h00 06h00 06h00 Giamensis complex Borneensis complex ≈ 09h00 09h00 09h00 12h00 ( 15h00 ( H. baangongensis H. cf.

18h00 borneensis 21h00 ) ) 00h00 

≈ ≈ 03h00 Pollen extrusion Intense odour Mild odour Resin droplets Staminate phase Interval Pisllate phase Hanneae complex 06h00 Day 3 ( H. debilicrista Parastasia Parastasia spathe Fully opened Chaloenus Colocasiomyia spp. spp. ) spp.

This article is protected Allrights bycopyright. reserved. Accepted Article

This article is protected Allrights bycopyright. reserved. Accepted Article

This article is protected Allrights bycopyright. reserved. Accepted Article

JQ955576. Santubong,Kuching, 01.44N;110.19E,P.C.Boyce Santubong, Mouth Homalomena velutipedunculata (SAR), JQ955577. Mariamma Matang, Maha Homalomena matangae 01.19 N;110.16E,P.C. Boyce Padawan, GiamVillage, Homalomena giamensis V Padawan, Sikog Homalomena gastrofructa Mariamman Temple, 01.35 N;110.13 Mariamman Temple,01.35 Homalomena debilicrista JQ955573. &N; 110.16E,P.C.Boyce (SAR), S.Y.Wong Ar2559

03 03 02 02 01 01 00 .501 .50.20 0.15 0.10 0.05 -0.05 -0.10 -0.15 -0.20 -0.25 -0.30 -0.35 Homalomena JQ955572. S.Y. Wong110.20 E,P.C.BoyceSikog& Ar2574(SAR), Village,01.20N; Homalomena baangongensis alphabetically. arranged are Taxa number. GenBank accession Appendix 1. This article is protected Allrights bycopyright. reserved. Accepted Article List Taxon, investigated: ofspecimens cf. cf. borneensis illage, 01.20 N;110.20E,P.C. illage, Boyce Y.C.Hoe, S.Y.Wong & P.C.Boyce. MALAYSIA. Sarawak: Kuching, Kuching, Sarawak: & P.C.Boyce. MALAYSIA. Y.C.Hoe,S.Y.Wong L.S.Tung, S.Y.Wong & P.C.Boyce. MALAYSIA. Sarawak: Kuching, L.S.Tung, Kuching, Sarawak: &P.C.Boyce. S.Y.Wong MALAYSIA. n Temple,01.35N;110.13E,P.C. Y.C.Hoe, S.Y.Wong & P.C.Boyce. MALAYSIA. Sarawak: Kuching, Kuching, Sarawak: & Y.C.Hoe,S.Y.Wong MALAYSIA. P.C.Boyce. Y.C.Hoe. MALAYSIA. Sarawak: Kuching, Matang, Maha Kuching, Maha Matang, Y.C.Hoe.MALAYSIA. Sarawak: . MALAYSIA. Sarawak: Kuching, Padawan, Giam Village, 01.19 L.S.Tung & Y.C.Hoe. MALAYSIA. Sarawak: Kuching, Padawan, Sarawak: MALAYSIA. L.S.Tung& Y.C.Hoe. S.Y.Wong, Y.C.Hoe & P.C.Boyce. MALAYSIA. Sarawak: Sarawak: MALAYSIA. Y.C.Hoe&S.Y.Wong, P.C.Boyce. E, Y.C.HoeAr3057(SAR),JQ955574. -0.15 -0.10 -0.05 0.05 0.10 0.15 0.20 0.25 0.30 -0.25 -0.20 collection locality, GPS, voucher, and and GPS,voucher, collectionlocality, et al. et

et al. et Ar1691 (SAR), JQ929129. JQ929129. Ar1691(SAR), Ar2575 (SAR), JQ955575. JQ955575. Ar2575(SAR), Boyce & Jeland Ak Kisai Ar230 Boyce& JelandAkKisai Ar230 et al. et

Ar2103.(SAR), (pisllate phase) H. matangae (pisllate phase) H. giamensis (pisllate phase) H. baangongensis (staminate phase) H. velupedunculata (pisllate phase) H. velupedunculata (staminate phase) H. gastrofructa (pisllate phase) H. gastrofructa (staminate phase) H. debilicrista (pisllate phase) H. debilicrista