\ociobiologl 6l(-l): 2lJ6-292 (Scptcrribcr 2014) lX )l : I (1. I i I 02isoc iobiokrgr.v(r I i"1.2ll(r-192 Sociobiology An intemational .ioumal on social insccts Mutualistic relationships between the shield ant, Meronoplus bicolor (Gu6rin-Meneville) (Hymenoptera: Formicidae) and honeydew-producing hemipterans in guava plantation I BURIKAM, D KANTHA KASETSART UNIVERSIry, NAKH?N PATHOM, THAILAND Article History Abstract Mutualistic relationships between the shield ant, Meronoplus bicolor (Guerin- Edited by M6neville), and two species of hemipteran, Aphis gossypii Glover and Ferrisio virgoto Jacques H. C. Delabie, UESC, Brazil (Cockerell), were investigated in an unsprayed guava plot at Kamphaeng Saen, Nakhon Received 10 Deceber 2013 field and laboratory lnitial acceptance 19 May 2014 Pathom, Thailand. The reciprocal benefits were observed in both Final acceptance 20 July 2014 studies. M. bicolor activity coincided with peak seasonal activity of both hemipterans during.lune-August. We indicated two sets of support evidence in M. bicolor honeydew Keywords preference: (i) statistically higher value of adjusted honeydew weight collected by ant cotton aphid, striped mealvbug, coc- workers from A. gossypiicompared with that from E virgoto (p-value = .005), and (ii) cinellids, syrphid fly, Psidium guojovo the higher value of the strength of effect (r1' = '62]'in the total variance of multi-species physical property on honeydew viscosity was discussed concerning Corresponding author association. The between-subjects lntawat Burikam ant preference. we used two-group, ant-tended and ant-excluded, benefits' Department of EntomologY multivariate analysis of variance (MANOVA) in order to show hemipteran Kamphaeng together with Faculty of Agriculture at Both hemipteran populations increased in the ant-tended treatment, Saen, Kasetsart UniversitY (Fabricius) and lesser amounts of two species of coccinellids , Menochilus sexmoculotus Nakhon Pathom 73140, Thailand fly, Pseudodorus clovotus coccinello tronsversalis Fabricius, and one species of syrphid E-Mail : [email protected] (Fabricius),comparedwiththeantexclusiontreatment(Svalue<.001).Thefacultative hemipteran species were mentioned' mutualistic relationships of M. bicolor and the two (Delabie' 200 I )' ants are rnostll facultative or opportunistic lntroduction hctniplcrans Cienerally. ants benetrt liom associations with tbod source itl tlre lbrrl of (Cuerin-M6nevi I le) by obtaining carbohydrate-rich sh ield anl. il'le r u nLt pl u s b i c ol ttr The fronr hemipterans (e'g': Nixon' 195 l: ground nesting spe- "llon"yd.*; secreted (Hymenoptera: Formicidae). is a cotnmon "l Specifical11" the Way, 96-i; Hollclobler & Wilson' 1990) tbragirrg behavior' .i.,orthesubfamil.vMyrmicinae.andiswidelydistributed to ants have beetr focused on the Region (Schddlh' 1998)' The U.trlnt, throughout the entire Oriental (Stadler & Dixon' 20051 Grover et al'' 2007: as scaveugers' of rvorker ants not only forage on dead arthropods olr fittress betrefits *ork.., et aI..20 l0)' Sonre have concetrtt'alecl carbohydrate source tionl Kay & but also collect honeydew as growth (Grover et al ' 20071 [lehns Glover (He- in tertns of ant colony the cotton aphid' gossvpil ln rettrnr the berlefits' ants hemipterans. e.g. "lphis Vinson,2008; Wilder et al'' 20 Il)' I'crrisia virgttttt products' OOn'Oitl onO the striped rnealy'bug' contamination of their waste ,'OtJ*t eco- nray reduce hemipteran in agricultural natural enenries' and (Cockerell) (Hemiptera: Pseudococcidae)' ;";il dead individuals' protecting sites' resulting in the svstem.However,thetlophobioticrelationshipsornttrtualism hemipterans to new feecling 'J.,r..r' hemipterans are transport 1963: Nielsen andltoneydew-producing populations (e'g': Way' ii r,' ot u' abundance of hemiptetan 2005)' Ants e\ploit hcnripterans unknown. .ili.. ,oto, Stadler'& Dixori' alld honeydew-producing also as a.protein source Mutualism between ants for their honeyderv' btrt of relation- not only (B-uckleY' 1987: iientified as a contitluttnr us a conlmon prey hemipterans has been when tbraging on tl"re"' (Stadler & 200 l)' However' this rnutualistic to antagonistic Wilson' lg'nt ships ranging from by Htrlldobler & anA hemipterans tending '"tobi"' Dixon. 2005; eif f i'r tt;i-looz)' phplsociobrologv http //perrochcos uefs'brlols/indcx Open access .lournal' tSsN ult' t-t':r: Sociobiolog_v 6 l(3): 2lt6-2t)2 (Scptcnrhcr 201-l; 107 type of antagonistic relationships will not be treated here; tured in an empty hard gelatin capsule (size 0; outer diarneter we are looking at a concrete evidence of mutually benefits 7.6-5 nrnt. height 21.7 mnt. and volume 0.68 ml ol'Ibrpac among both partners. lnc." NJ), and shortly after. the capsule containing the arlcstecl In this stud1, we '"'elified, in both field and laboratorl ant was weighed on a digital balance. I hc aclu:il ant wcight experiments. thc reciprocal benefits of .l,l hicolor ancl two was obtained fronr the sutrtraction o1'the capsulc wciglrt. \\'e species o1'horreldew producing henr ipterans. l. grr.r.r'r7,lli and rveighed. tionr lleld collectccl. t\vo scts (n 20()) lirraSirrg ants l'. virguttt. We concentrated lbr r)ver three ntonth period in visiting.l go.s.rr7rii. arrd one sct (n . 100) ol'ants v'isiring l. -lhe the guava plantation ol' llorticLrlture f)epartnrent, Kasetsart virguttt. honeyclera, loacls were corrlirrned ra,ith tlre labo- University. Nakhon Pathorrr, Thailand, observing rhe mutu- rator-v- set up by' l'eeding ol ll ltit'olor rvorkers rvith hone-r,- alism ofant hemipterans including the abundance ofnatural de'*'. A set of field collected workers (n: I00) leaving their enelxies. nlainly predatom. We tested three hypotheses: (i) ants nests for foraging were randonrly chosen. holding irr captivitl' receiving bencfits in temrs of lronevdew fiom rnutualistic lor 24 hours rvithout fbod, and subsequenlll captured inside associations in guava agroecosysterl; (ii) ants protecting he- the gelatin capsule tbr weighirrg. .4fter weighing. halt'ot-the mipterans fiom natural enenlies therefbre the densities of natu- 24-hcrur arrested ,\'l bicolor was offered with quava lea'"'es ral enemies decrease in the presence of ants; and (iii) in con- occupied by honeydew exudates of ..1. gr.r.r,r-r7rii. and the other sequence ofthe two hypotheses nrentioned earlier. resulting half of ants with honeydew fi'orn l. virgata. The ants were in the incrernents of henlipterarr densities in ant hemiptelan allowed to feed on honeydew until they either refused to feed associations compared with the ant exclusion arrangelnent. or left the guava leave. All tl'(. bic'olor wolkers were rveighed fol the second tinre in order to obtain honeydew loads befbre Vlaterials & Methods releasing back to their fbrnrer habitats. St.ud\' ,sltcc:ie.s I Ienriptct'an be ncfit.r The study was conducted dLrring April-.December We randonrly' selected 30 guava trees. age 61'ears old. 20l2 in the unsprayed varietal collection plots (valieties: approximately 1.65 m in height and 2.5 2.75 rn in dianreter Phant Si Thong. Kim Ju" and Vhan Pi Roon). consisting ol' from the pesticide free guava plot as our study units. One of 336 guava trees, P.sicliunr guctf uvct, of Horliculture Depart- tr.r,cl similar branches rvas randonrly chosen lionr each selected nrent. Faculty of Agriculture at Kanlphaeng Saen. Kasetsart tree to perfornr ant-exclusion treatrnent. using sticky" barrier L.lniversity, Thailand ( 14.0358 "N. 99.9826 "E,). The predonr- around the base ofthe branch cov'ering 20 cnr in length. The inant ground'-nesting ant species in the study area was the na- tatget branch was first wrapped atound with plastic'uvrap" and tive ,1,1 bicolor. with only a few colonies of the invasive aut then applied with generic horticultural glue (colorless ancl species the tropical fire-ant. Solenopsis geminutct (Fabricius) odorless). The objective ofthe gluey barlier is to prevent ants near the perinleter of the plantation. The honeydew-producing and other crawling insects fiom reaching hemipteran colonies hemipterans were ..1 gossl,pii and l:. t'irguta. The natural at the guava shot'rts, allor.r'ing only the entering o1'air-borne enemies. mainly predators. were two species of coccinellid insects, including rvinged aphids. mealybug crarvlers" ladv- (' beetles. l'1 e nrsc hi I u s .s ex nacu I atu s ( Fabri ci us ) and oc c i nc I I Lt bugs, and syrphid llies. The barriers were exatninecl periocli- trunsversulis F'abricius (Coleoptera: Coccinellidae). and one cally, and reapplied the glue as required, in orcler to rnaintain species of syrphid ffy. Pseudodorus c'lat,altls (FabriciLrs) the efl'ectiveness as ant balriers throughout the experimental (Diptera: Syrphidae). period. The other branch rvas left untnanipulated as the ant presence treatnrent. There was the total of 60 experinrental .,1til henefit untl hone|dey, pre/ercnce units. This ant-exclusion/presence experinrerrt wtrs started in Vlay. treginning with equal nurnbers of both .'l go,r',r't7rii and The direct benefit ol ,\'1. bic'oltr was obtained by weigh- l'. t'i'g,uttt between the two tt'eatlrents on the satnc guava trec. ing a certain numbel of tbraging atrts, attd then calculating the Insect observations were ntade during peak seasonal actil'i- difference of weight gain between lbragers descending and ties of both hemiptel'ans and their natural enenties in June ascending the guava branches. We trteasured weight gains of August 20 I 2. l,l hic:olor afler visiting hemipteran colonies as honeydew On each clrosen guava tree. we randomly selected one receiving. We randorrrlv chose foraging ants tionr the field to terminal shoot fi'om the total of J-5 shoots of each experi- rveigh tbr honevdew loading: 50 ant foragers ascending the mental unit. in order to make observations. All terminal shoot guava branch before leaching herniptelan colonies. and the belonging to each expelinretttal unit had att equal chancc to other' 50 individuals descending the blanch with full load of be picked on each data collection day.'lhe number of he- honeydew. I{oneydew loads were nleasured frotn the weight nripterans: A.