1AT+,67. B8//. S,$0 S2& ² TREE TRUNK TOPOGRAPHY MODIFIES THE WEBS OF THE ARBORICOLE SPIDER, HERENNIA MULTIPUNCTA (DOLESCHALL, 1859) (ARANEAE: NEPHILIDAE) Timothy C. Hawes 1 ABSTRACT The arboricole spider, Herennia multipuncta (Doleschall, 1859), actively colonizes areas in ZKLFKSULPDU\IRUHVWKDVEHHQHLWKHUORVWRUUHSODFHGE\SODQWHGWUHHV7KHEHQHÀWVRIVXFKSODVWLFLW\ IRUWKHVXUYLYDORIWKHVSHFLHVLQPRGHUQ6RXWKHDVW$VLDDUHWUDQVSDUHQW+RZHYHUQLFKHSODVWLFLW\ LVDJHQHUDOLVWVWUDWHJ\WKDWVHHPVDWRGGVZLWKLWVVWDWXVDVDVSHFLDOLVWWKDWPDNHVDKLJKO\GHULYHG ZHEIRUP ODGGHUZHEV $OWKRXJKVRPHFRORQL]HGWUHHVPD\RIIHUHTXLYDOHQWRUHYHQEHWWHUVLWHV IRUZHEORFDWLRQPDQ\PD\EHSUHGLFWHGWRSURYLGHOHVVWKDQLGHDOZHEVXEVWUDWHV%DUNH[WUXVLRQ LQSDUWLFXODUFDQFRPSURPLVHZHESURSHUWLHVLQQXPHURXVZD\VDQGIXOO\UHDOL]HGODGGHUZHEV DUHRSWLPDOO\ORFDWHGRQVPRRWKVXEVWUDWHV,QRUGHUWRTXDQWLI\ZKDWHOHPHQWVRIVSHFLDOL]DWLRQ KDYHEHHQWUDGHGRIIDJDLQVWWKHEHQHÀWVRIQLFKHH[SDQVLRQH. multipuncta ladder webs on secondarily planted trees of Acacia mangium:LOOGZLWKURXJKVXERSWLPDOWUXQNVXUIDFHVZHUH H[DPLQHGIRUORVWDQGUHWDLQHGFKDUDFWHULVWLFV2QO\WKHGHULYHGKXEFXSZDVXQLYHUVDOO\NHSWLQ WKHVH´QRIULOOVµODGGHUZHEV2EVHUYHGPRGLÀFDWLRQVWKDWFRPSHQVDWHGIRUGHJUDGDWLRQRIWKH HerenniaDUFKHW\SDOZHEWHPSODWHLQFOXGHGSODVWLFVLWHVSHFLÀFDGMXVWPHQWVRIWKHKXEFXSWR tree microtopography and alternative web forms. Keywords: Acacia mangium, arboricole, Herennia multipuncta, ladder web, plasticity ,1752'8&7,21 ,Q´7KH&RPLW\RI6SLGHUVµBRISTOWE (1941) fondly recalled that Herennia spiders “were FRPPRQLQVRXWKHUQ6LDPµDQGWKDWKHRIWHQ´PDUYHOOHGµDWWKHP´SUHVVHGÁDWDJDLQVWWKH VLOYHU\JUH\WUXQNVRIWKH.DSRNWUHHVµ7RGD\DVDUHVXOWRILWVUHODWLYHO\ODUJHVL]H DGXOW IHPDOHVUHDFKDOHQJWKRIFD²PP LWVWUHHOLYLQJKDELWVDQGLWVEHDXWLIXOO\RUQDWHZHEV Herennia multipuncta )LJ LVVWLOORQHRI7KDLODQG·VVLJQDWXUHVSLGHUV+RZHYHULQWKHRYHU KDOIFHQWXU\VLQFHBRISTOWE’s (1941) reminiscences the habitat potentially available to the VSLGHUVKDVVKUXQNFRQVLGHUDEO\LQDEVROXWHWHUPVLQSDUWLFXODUDVDUHVXOWRIWKHSHULRGIURP 1976–1989 when 28% of forest cover in Thailand was permanently lost (CROPPER ET AL., 1999). 'HIRUHVWDWLRQLVDQHQGHPLFSUREOHPLQ6RXWKHDVW$VLDDQG7KDLODQGLVQRH[FHSWLRQWR WKHUXOHDOWKRXJKWKHJUHDWHVWORVVHVDUHQRWFRQWHPSRUDU\EXWRFFXUUHGGXULQJWKHH[FHVVHV of development in the second half of the 20thFHQWXU\EHIRUH´JUHHQµWKLQNLQJKDGDFKLHYHG DQ\GHJUHHRIPDLQVWUHDPSUHVHQFH*UHDWHUSULRULWL]DWLRQRIWKHHQYLURQPHQWLVUHÁHFWHGLQ UHFHQWDVVHVVPHQWV)RUH[DPSOH7KDLODQGVKRZHGWKHORZHVWSHUPDQHQWORVVHVLQIRUHVWFRYHU 1,QWHUQDWLRQDO&ROOHJH.KRQ.DHQ8QLYHUVLW\0LWUDSKDS+LJKZD\.KRQ.DHQ7KDLODQG E-mail: [email protected] 5HFHLYHG-XO\DFFHSWHG2FWREHU 29 TIMOTHY C. HAWES DPRQJWKH0HNRQJ%DVLQFRXQWULHVLQWKHÀUVWGHFDGHRIWKHstFHQWXU\ LEINENKUGEL ET AL., 1RQHWKHOHVVGHVSLWHDQLPSUHVVLYHV\VWHPRIQDWLRQDOSDUNVDQGUHVHUYHVWKH FRQWUDFWLRQRI7KDLODQG·VDYDLODEOHSULPDU\DQGVHFRQGDU\IRUHVWKDELWDWVRXWVLGHRISURWHFWHG DUHDVKDVKDGDODUJHO\XQNQRZQLPSDFWRQODUJHVZDWKHVRILWVRULJLQDOÁRUDDQGIDXQD HJ DEELEMAN-RHEINOLD, 2001). ,QWKLVFRQWH[WH. multipuncta LVDQLQWHUHVWLQJVWXG\PRGHO,WLVDQREOLJDWHDUERULFROH EHFDXVHLWLVREOLJHGWROLYHRQWUHHWUXQNVDVDUHVXOWRIHYROXWLRQDU\VSHFLDOL]DWLRQDOWKRXJK RFFDVLRQDOO\LWFDQDOVRXWLOL]HDOWHUQDWLYHKDELWDWVWKDWRIIHUDQDORJRXVVWUXFWXUDORSSRUWXQLWLHV 7KHPDLQEDVLVIRUWKLVFRQWLQXHGGHSHQGHQFHRQWUHHVKDVEHHQWKHHYROXWLRQRILWVDQFHVWUDO orb web into a “ladder web” (Fig. 2). /DGGHUZHEVDUHHORQJDWHGZHEVLQZKLFKWKHYHUWLFDOGLPHQVLRQH[FHHGVWKHKRUL]RQWDO GLPHQVLRQWRWKHH[WHQWWKDWWKHLUVKDSHUHVHPEOHVDODGGHU7KHÀUVWGHVFULSWLRQRIWKLVZHE W\SHKDVEHHQWUDGLWLRQDOO\DWWULEXWHGWRROBINSON & ROBINSON 6LQFHWKHLUXVHRIWKH WHUPODGGHUZHEVKDYHEHHQLGHQWLÀHGLQDQXPEHURIXQUHODWHGIDPLOLHVDQGJHQHUD EBERHARD, 1975; STOWE, 1978; ROBINSON & LUBIN, 1979; FORSTER & FORSTER, 1985; KUNTNER ET AL., 2008, 2010; HARMER & FRAMENAU, 2008; HARMER 7KH\DUHRISDUWLFXODULQWHUHVWEHFDXVHRI WKHLUXQXVXDODUFKLWHFWXUH HJ. EBERHARD, 1975; ROBINSON & LUBIN, 1979; FORSTER & FORSTER, LQWHUDFWLRQVZLWKVXEVWUDWH HJKUNTNER ET AL., 2010) and/or prey specialization (e.g. EBERHARD, 1975; STOWE, 1978), and as a model for the plasticity of the web template (e.g. HARMER & FRAMENAU, 2008; HARMER, 2009; HARMER & HERBERSTEIN, 2009). SIMON (1894) described HerenniaZHEVLQ6UL/DQNDDVVWUHWFKHGRUELFXODUZHEV +RZHYHUDOWKRXJKSIMON ZDVWKHÀUVWWRHPSKDVL]HWKHRUQDWHQHVVRIHerennia webs, WKHÀUVWGHVFULSWLRQRIODGGHUZHEVDVZHNQRZWKHPWRGD\FDPHIURP2DWHV LQTHORELL [@ (XJHQH:2DWHVFROOHFWHGWKH%XUPHVHVSLGHUVWKDWIRUPHGWKHEDVLVRI7KRUHOO’s ´'HVFULSWLYH&DWDORJXHRIWKH6SLGHUVRI%XUPDµ 2DWHVDOVRSURYLGHG7KRUHOOZLWK VRPHREVHUYDWLRQVRQWKHVSLGHUVLQWKHFROOHFWLRQVRPHRIZKLFK7KRUHOOLQFOXGHGZLWKKLV species descriptions. THORELL·V FDWDORJXHRI%XUPHVHVSLGHUVLVRQHRIWKHIRXQGLQJ WH[WVRQWKHV\VWHPDWLFVRI6RXWKHDVW$VLDQVSLGHUV$OWKRXJKWKHGHVFULSWLRQVZHUHDFFHVVLEOH WRKLVFRQWHPSRUDULHVWKH\UHPDLQODUJHO\LQDFFHVVLEOHWRUHDGHUVQRZGXHWRWKHLUXVHRI/DWLQ DQGODFNRIÀJXUHV+RZHYHURQSDJHLQKLVGHVFULSWLRQRIH. multipunctaKHTXRWHG 2DWHV·VGHVFULSWLRQRIWKHZHELQ(QJOLVK ´5DQJRRQ0DNHVDZHEDERXWIHHW FP ORQJRQDVPRRWKWUHHWUXQN:LGWK ѿ or ¼ of girth of tree. All the lines are vertical, forming a perfect rope ladder. The web follows WKHFRQYH[LW\RIWKHWUXQNDQGLVHYHU\ZKHUHDERXWô LQFK FP IURPLW9HUWLFDOVDERXW LQFK FP DSDUWKRUL]RQWDOVDERXWõLQFK FP DSDUWµ>0HWULFFRQYHUVLRQVDGGHG LQEUDFNHWVLWDOLFVDGGHGIRUHPSKDVLV@ 7KXVWKHÀUVWDSSHOODWLRQRI´ODGGHUµPD\EHDWWULEXWHGWR2DWHV·V observations and LQGHHGVRPD\WKHÀUVWDFFXUDWHGHVFULSWLRQRIWKHZHERIH. multipuncta. That ROBINSON & ROBINSON ODWHUXVHGWKHVDPHDSSHOODWLRQQHDUO\DFHQWXU\ODWHULVWHVWLPRQ\WRWKH VXLWDELOLW\RIWKHWHUP,QIDFW2DWHV·´URSHODGGHUµLVSHUKDSVDQHYHQPRUHDSSRVLWHWHUP JLYHQWKHDQDORJRXVSURSHUWLHVRIVSLGHUVLON )URPDQDUFKLWHFWXUDOSHUVSHFWLYHHerenniaZHEVPD\EHFRQVLGHUHGWKHH[HPSODURIWKH ladder form par excellenceDVDUHVXOWRIDQXPEHURIXQLTXHZHEHOHPHQWVWKDWFRPSOHPHQW HORQJDWLRQZHEFXUYDWXUHDQGWKHKXEFXSDUHRISDUWLFXODUQRWHWKHIRUPHUHQDEOLQJWKH VSLGHU·VZHEWRDFKLHYHWKHVHHPLQJO\LPSRVVLEOHHQJLQHHULQJIHDWRIFXUYLQJLWVZHESODQH DURXQGDWUHHWUXQN 75((7581.7232*5$3+<02',),(67+(:(%62)$1$5%25,&2/(63,'(5 (a) (b) )LJXUH $IHPDOHDUERULFROHVSLGHUHerennia multipuncta, ERG\OHQJWKPP DWLWVZHEKXERQ DWUHHWUXQN+XDL<DL%DQJ/DPXQJ&KRQEXUL7KDLODQG D GRUVDODVSHFWDQG E ODWHUDO aspect with prey. +RZHYHUWKHVHXQLTXHWUDLWVRIH. multipuncta’s ladder web template mean that its webs DUHDUFKLWHFWXUDOO\EHVWVXLWHGWRWUHHVLQZKLFKWKHWRSRJUDSK\RIWKHWUHHWUXQNLVVXIÀFLHQWO\ VWUHDPOLQHG UHODWLYHO\VPRRWKVXUIDFH WRIDFLOLWDWHWKHLUH[SUHVVLRQ7KLVVWXG\WHVWVWKH K\SRWKHVLVWKDWQLFKHH[SDQVLRQRQWRWUHHWUXQNVZLWKURXJKH[WUXVLYHWRSRJUDSKLHVOHDGVWR a degradation of the archetypal HerenniaZHEWHPSODWH PRGLÀFDWLRQDQGRUORVVRIGHULYHG ZHEHOHPHQWV $ÀHOGVWXG\ZDVFDUULHGRXWRQDFRORQL]LQJSRSXODWLRQRIH. multipuncta on Acacia mangiumWUHHVZKLFKKDYHDPRUHUXJRVHVXUIDFHWRSRJUDSK\A. mangium is a SDUWLFXODUO\UHOHYDQWWHVWRIWKHVWDWHGK\SRWKHVLVEHFDXVHWKLVVSHFLHVZKLFKRULJLQDWHGIURP $XVWUDOLDDQG3DSXD1HZ*XLQHDLVQRZVHFRQGDULO\SODQWHGWKURXJKRXW6RXWKHDVW$VLD SDUWLFXODUO\LQDUHDVWKDWKDYHEHHQVXEMHFWWRURDGVLGHGHYHORSPHQWDQGDWVLWHVZKHUHODQG LVEHLQJUHFODLPHGDIWHUFOHDUDQFHIRUFRQVWUXFWLRQ 0(7+2'6 Acacia mangium:LOOGZHUHLGHQWLÀHGZLWKUHIHUHQFHWRJENSEN (1999). Spider systematic QRPHQFODWXUHIROORZVWKHWORLD SPIDER CATALOG (2015). A copse of ca. 150 planted A. mangiumWUHHVZDVVXUYH\HGLQ)HEUXDU\LQWKHFHQWUDOHDVWHUQSURYLQFHRI&KRQEXUL Thailand, for webs of H. multipuncta,QFOXGLQJSUHYLRXVSLORWREVHUYDWLRQVWKHWRWDOQXPEHU of H. multipuncta IRXQGRFFXS\LQJWKHFRSVHZDV$WWKHVWDUWRIWKHVWXG\HLJKWLQGLYLGXDOV TIMOTHY C. HAWES ZHUHIRXQGWRKDYHHLWKHUUHORFDWHGRUEHHQSUHGDWHGVRSDUDPHWHUVIRUZHEVZHUHFROOHFWHG GXULQJWKHVWXG\SHULRGDQGDUHXVHGKHUH 7KHIROORZLQJPHDVXUHVZHUHPDGHVSLGHUERG\OHQJWK PP KHLJKWRIKXEDERYHJURXQG FP FRPSDVVRULHQWDWLRQRIZHESODQHDVGHWHUPLQHGIURPKXEFXSWUHHFLUFXPIHUHQFH FP ZLGWKDQGOHQJWKRIVWLFN\FDSWXUHDUHD FP GLVWDQFHRIKXEWRWRSRIVWLFN\FDSWXUHDUHD FP GLVWDQFHRIOHIWVLGHIUDPHWRKXE FP GLVWDQFHRIZHESODQHWREDUNIURPKXE FP and presence and ratio of frame side-attachments. The ladder web template of H. multipunctaLVVXPPDUL]HGLQ)LJXUHHerennia web HOHPHQWVWKDWZHUHHLWKHUUHWDLQHGRUPRGLÀHGZHUHQRWHGIRUHDFKLQGLYLGXDOZHE7KHLU presence in the A. mangium SRSXODWLRQZDVFRPSDUHGLQWHUPVRISHUFHQWDJHRFFXUUHQFH 7KHIROORZLQJZHEHOHPHQWVZHUHUHFRUGHG KXEFXS YHUWLFDODV\PPHWU\ SDUDOOHO VLGHIUDPHV SVHXGRUDGLL FRQWDFWZLWKEDUN FXUYDWXUHDURXQGWKHWUHHWUXQNVXUIDFH UHWHQWLRQRIZLWKLQIUDPHWHPSODWHVXUIDFHDUHDDQG XVHRIWUXQNPLFURWRSRJUDSKLF )LJXUH /DGGHUZHEWHPSODWHRI Herennia multipunctaRQVPRRWKWUHHVXUIDFH D LGHDOL]HG UHSUHVHQWDWLRQVKRZLQJJHQHUDODUFKLWHFWXUHDQGGHULYHGHOHPHQWV VWUDLJKWOLQHVUHSUHVHQW SVHXGRUDGLLGDVKHGOLQHVUHSUHVHQWVWLFN\VLON E SKRWRJUDSKRIDGXOWIHPDOHVLWWLQJLQKXE FXSZLWKZHESODQHFXUYLQJDURXQGSenna siamea /DP ,UZLQ %DUQHE\WUHHWUXQN H. p. LQGLFDWHVIHPDOHVLWWLQJDWKXEFXUYHGDUURZGHQRWHVZHEFXUYDWXUH F SKRWRJUDSKRIZHE PHVKORRNLQJXSS. siameaWUHHWUXQN 3UGHQRWHVUHSUHVHQWDWLYHSVHXGRUDGLXV 75((7581.7232*5$3+<02',),(67+(:(%62)$1$5%25,&2/(63,'(5 GHSUHVVLRQVDQGXQGXODWLRQVWRVLWXDWHWKHKXEFXSGHHSHUDQGIXUWKHUDZD\IURPWKHZHE SODQH(OHPHQWVDQGIROORZWKHQRPHQFODWXUHLQWURGXFHGE\ROBINSON & LUBIN (1979). +XEFXSVDUHVRFDOOHGEHFDXVHWKHKXEKDVEHHQWXUQHGLQWRDVXQNHQIXQQHORU´FXSµZKLFK VLWVEHORZWKHZHESODQHDQGLQDOOEXWWKHHDUOLHVWLQVWDUVDWWDFKHVWRWKHEDUNSVHXGRUDGLL GRQRWUDGLDWHIURPWKHKXEDV´WUXHµUDGLLGRLQRUEZHEVEXWUXQYHUWLFDOO\GRZQWKHODGGHU (ROBINSON & LUBIN, 1979). 3DUDPHWHUVEHVWVXPPDUL]HGLQWHUPVRISUHVHQFHDQGDEVHQFHZHUHKXEFXSFXUYDWXUH SDUDOOHOVLGHIUDPHVSVHXGRUDGLLXVHRIPLFURWRSRJUDSK\DQGZHEFRQWDFW5HGXFWLRQVWR ZLWKLQIUDPHWHPSODWHFDSWXUHVXUIDFHDUHDZHUHWRRFRQWH[WVSHFLÀFWRTXDQWLI\EH\RQG SUHVHQFHDEVHQFHEXWUHSUHVHQWDWLYHGHVFULSWLRQVRIVRPHLQVWDQFHVRIWKHVHDUHGHVFULEHG DQGSUHVHQWHG:LWKLQIUDPHWHPSODWHUHGXFWLRQVLQVXUIDFHDUHDUHIHUWRORVVHVRIFDSWXUH DUHDWKDWDUHQRWGHVFULEHGE\OHQJWKZLGWKPHDVXUHV³LHZKHUHWKHZHE·VOHQJWKDQGZLGWK