Revista de Biología Tropical ISSN: Universidad de Costa Rica Costa Rica

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1 Revist de Biologí Tropil ISSN: Universidd de Cost Ri Cost Ri Trnhid, Mrí C.; Miieli, Mrí V.; Miá, Arnldo; Grí, Jun J. Ntive Argentinen ylopoids (Cruste: Copepod) s predtors of Aedes egypti nd Culex pipiens (Dipter: Culiide) mosquitoes Revist de Biologí Tropil, vol. 7, núm. 4, diiemre, 29, pp Universidd de Cost Ri Sn Pedro de Montes de O, Cost Ri Aville in: How to ite Complete issue More informtion out this rtile Journl's homepge in redly.org Sientifi Informtion System Network of Sientifi Journls from Ltin Ameri, the Crien, Spin nd Portugl Non-profit demi projet, developed under the open ess inititive

2 Ntive Argentinen ylopoids (Cruste: Copepod) s predtors of Aedes egypti nd Culex pipiens (Dipter: Culiide) mosquitoes Mrí C. Trnhid 1*, Mrí V. Miieli 1,2, Arnldo Miá 1,3 & Jun J. Grí 1,4 1. Centro de Estudios Prsitológios y de Vetores, CEPAVE, (CCT-L Plt-CONICET-UNLP), Clle 2 nº 84, (19) L Plt, Buenos Aires, Argentin; *Corresponding uthor: trnhid@epve.edu.r 2. vmiieli@fnym.unlp.edu.r 3. Reserher ssistnt CIC: mi@epve.edu.r 4. Reserher CIC:jun@epve.edu.r Reeived 13-vi-28. Correted 12-ii-29. Aepted 13-iii-29. Astrt: Copepods from L Plt, Argentin were investigted to hrterize the lol ommunity of lrvivorous opepods inhiting mosquito reeding sites nd to identify new predtor speies of the mosquitoes whih our in rtifiil ontiners, Aedes egypti nd Culex pipiens. Diversity of lrvivorous ylopoids ws highest in permnent pools. Predtion y sex nd ge, seletivity on mosquito speies, nd dily predtion rte during five dys were studied for Anthoylops roustus, Diylops uruguyensis, Mroylops lidus nd Mesoylops longisetus. Femle opepods presented the highest predtory pity. No predtory preferene for mosquito speies ws found. Aording to overll predtion potentil, opepods were rnked s follows: D. uruguyensis < A. roustus < M. lidus < M. longisetus. Copepod tolerne to desition nd pity to survive in wter from rtifiil ontiners were lso evluted. D. uruguyensis nd A. roustus survived under dry onditions, ut D. uruguyensis showed lower survivl in wter from emetery flower vses. M. lidus did not survive under dry onditions nd did not tolerte wter extrted from rtifiil ontiners. M. longisetus survivl ws not severely redued fter desition or reeding in wter from flower vses. The Neotropil ylopoids D. uruguyensis nd A. roustus n e onsidered good ndidtes nd merit further reserh s iologil ontrol gents for mosquitoes. Rev. Biol. Trop. 7 (4): Epu 29 Deemer 1. Key words: Copepod, mosquitoes, lrvl predtion, iologil ontrol, Argentin. Cylopoid opepods re importnt memers of freshwter ommunities, eing the most undnt onsumers mong plnktoni tx. Mny speies of opepods hve een shown to kill mosquito lrve (Surez et l. 1984, Riviere et l. 1987, Mrten 1989, 199, 199, Mrten et l. 1994, Brown et l. 1991), the group hs een regrded s the most effiient mong ll inverterte predtors of Culiide (Mrten nd Reid 27). Field studies on mosquito ontrol using opepods hve een rried out minly on mn-mde wter ontiners (Mrten nd Reid 27), with suessful results in some ses (Mrten et l. 1994, Gorrohotegui-Eslnte et l. 1998, Nm et l. 2). These studies hve shown tht some ylopoids re pproprite to e inorported into progrms to omt prtiulr vetors, or to lower their popultion levels. It is dvisle to gther further informtion regrding new, lol speies of opepods efore implementing their use s iologil ontrol gents. In Argentin, no extensive survey of the lol opepod fun hs een undertken to the present in order to serh for new potentil predtor speies. Only single speies, Mesoylops nnultus Wierzejski, hs een ssessed in lortory trils (Miieli et l. 22), nd Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN ) Vol. 7 (4): , Deemer 29 19

3 under semi-nturl onditions (Mrti et l. 24), in whih it hs proven to e n effetive predtor of erly instrs of Aedes egypti L. However, tests re required for other speies of opepods of unknown potentil s mosquito predtors. Herein we present informtion on the potentil of some opepods ntive to Argentin for mosquito ontrol. In order to estlish whih speies of opepods re undnt in mosquito reeding ples from urn environments, field survey ws rried out in the re of L Plt ity, Buenos Aires provine, Argentin. Susequently we performed lortory evlutions of the potentil of some opepods s predtors of the most ommon mosquitoes ourring in rtifiil reeptles, nmely A. egypti nd Culex pipiens L. Our min interest is foused on these speies euse they frequently o-our in rtifiil wter ontiners ner humn environments nd re lso importnt vetors of humn pthogens. MATERIAL AND METHODS Study re: Field survey ws onduted in nd ner L Plt ity ( S, W). Severl types of mosquito reeding sites were smpled to detet ohittion in spe nd time of mosquito speies nd opepods. The surveyed freshwter sites were grouped into the following tegories: - Trnsient freshwter ponds: three shllow depressions in the ground, rnging from 2 to 1 m 2, filled y rinfll nd lsting from severl dys up to five weeks. - Permnent pools: two pools with floting vegettion, pproximte size 2 m long, 2 m wide nd 1 m depth eh. -Dringe dithes (2 m long,. m wide nd.4 m deep) loted in suurn re of L Plt ity. d- Rie fields: lrge fields with severl irrigtion nls eh, oupied y rie rops, rtifiilly flooded in Deemer nd mintined under wter until April. After tht, the fields remin flooded for vrile period ording to environmentl temperture nd rins. Only one flooded rie field ws seleted nd 4 internl irrigtion nls (2 m long,.2 m wide,.1 m deep) were smpled. e- Artifiil ontiners: flower vses mde of zin or ermi, with pproximtely 1 L pity from emetery in L Plt City, nd disrded vehile tires from the ity suurs. f- Nturl ontiners: wter-filled lef xils of Eryngium rere Pontiroli plnts (Apiee) whih re ommon in non-ropped fields surrounding the ity. Colletion of mosquitoes nd opepods ws rried out weekly during summer, using 1x1x1 m net (1 µm mesh) tthed to hndle. Live orgnisms were pled in plsti ontiners with wter from the sme site nd trnsported to the lortory. Some speimens were kept live for ulturing while others were preserved in 7% ethnol for txonomi identifition. Mosquito speies were identified ording to keys y Drsie (198) nd Lne (193). Copepods were identified following Reid (198) nd Ringuelet (198), nd their txonomi identity ws further onfirmed y S. Menu-Mrque, University of Buenos Aires, Argentin. Culture of opepods nd mosquitoes: Field olleted grvid femle opepods were pled individully in plsti ontiners with 1 ml of wter. As nutrient soure, we suspended ir g of powdered rit how in 2 ml of wter nd dded ml of this suspension to ultures. After hthing, the nuplii were trnsferred to new, ml-ontiners nd rised until the dult stge. Lrve of A. egypti nd C. pipiens were otined from olonies mintined y stndrd methods t CEPAVE, s desried y Miieli et l. (22). Evlution of predtion pity of opepods: Copepods olleted from the ovementioned reeding ples were exposed to individuls of the mosquito speies smpled t eh site. One dult femle of eh opepod speies ws exposed to young lrve in numers ording to vilility in 1 ml of wter in plsti eker. Three replites were performed for eh test. Predtion rte ws reorded dily. Any missing lrve ws onsidered s eten y opepods. Totl mortlity per ontiner ws sored s numer of missing lrve plus those ded (killed ut not eten y 16 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN ) Vol. 7 (4): , Deemer 29

4 the opepod), divided y numer of replites. A eker ontining only lrve of the tested mosquito speies served s untreted ontrol. No food soures were dded. Lortory predtion trils: Predtion pity of opepods otined from the field survey ws estimted through predtion trils, using immture individuls of A. egypti nd C. pipiens s prey. All experiments were onduted t ºC nd 12:12 hr (L:D) photoperiod. Dehlorinted tp wter ws used in ll tretments. Four speies of opepods were tested seprtely, with nine trils plus three ontrols (ontiners with lrve ut without opepods) eh. Numers of missing lrve were ompred y ANOVA, followed y Dunn s test for multiple omprisons etween tretments (Sokl nd Rohlf 1979). Experiment one: To nlyze predtion y single opepods, one femle dult, one mle dult, nd one lte opepodid were tested eh ginst 2 first-instr mosquito lrve in plsti ontiners (8 m dimeter) ontining 1 ml of wter. Experiment two: Seleted speies of opepods were evluted seprtely ginst ll instrs of A. egypti nd C. pipiens. One dult femle opepod nd 2 mosquito lrve of 1 st, 2 nd, 3 rd or 4 th instr were pled in seprte ontiners. Experiment three: The preferene of eh opepod speies for lrve of oth mosquitoes speies ws tested y exposing 2 seond instr lrve of A. egypti nd 2 seond instr lrve of C. pipiens to one femle of eh opepod speies in ontiners with 2 ml of wter. Experiments one, two nd three lsted 24 h nd the numer of missing lrve on eh tril ws reorded. Experiment four: Dily predtion rte of eh opepod speies ws exmined during five-dy tests. One femle opepod ws exposed to 2 erly instr lrve in ontiners with 1 ml of wter. Live lrve were ounted every 24 hours. The remining lrve were removed dily nd repled y new th of 2 lrve. Copepod tolerne to desition: In this experiment, the survivl pity of trgeted speies of opepods ws tested under dry onditions. We pled opepods of eh speies into plsti ontiner (8 m dimeter) with 2 m of sterilized snd sediment nd 1 ml of wter, t ºC nd 12:12 h (L:D), with three replites eh (totl: 3 ontiners). Twenty-four hours lter, stnding wter ws removed with pipette. One of the replites ws mintined with wter throughout the experiment. After period of 1 or 3 dys, the ontiners were flooded with wter nd the numer of live opepods ws reorded. Copepod survivl in wter from rtifiil ontiners: In order to test the survivl pity of opepods in wter from rtifiil ontiners without prey, the following experiment ws performed. We emptied 2 flower vses from the Cemetery of L Plt, lended ll ontents in single ontiner, nd filtered the wter with mesh (1 µm). As ontrol, the sme proedure ws done using dehlorinted tp wter. Fifteen dult opepods of eh seleted speies were dded to 1 ml of oth kinds of wter in plsti ontiners (8 m dimeter). Copepod mortlity ws reorded fter 7, 14 nd 21 dys. Three replites plus ontrol were used for eh speies (totl: 16 ontiners). RESULTS Field survey: Tle 1 shows the predtory pity of opepods upon eh mosquito speies otined from the field survey. Trnsient freshwter ponds ontined nturl popultions of M. nnultus nd Diylops uruguyensis Kiefer. At these sites, immture speimens of Ohlerottus lifsitus Mqurt nd Culex sp. were olleted. Both opepod speies preyed on first instr mosquito lrve. In the permnent pools the following lrvivorous ylopoids were found: Anthoylops roustus Srs, Mroylops lidus Jurine, Mesoylops longisetus Thiéud nd Metylops mendoinus Wierzejski. Additionlly, Etoylops ruesens Brdy, Euylops sp., Miroylops sp. nd Prylops sp. were Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN ) Vol. 7 (4): , Deemer

5 TABLE 1 Copepods found in the field survey nd their predtory pity on lol mosquito speies from L Plt, Buenos Aires provine Copepod speies Freshwter type Mosquito speies Seond Instr Lrve exposed (n) Mortlity (%) Mesoylops longisetus Permnent pool Culex sp. 1 8 Mroylops lidus Rie field permnent pool Culex sp. 1 8 A. litrsis 1 Anthoylops roustus Permnent pool Culex sp. 1 7 Metylops mendoinus Permnent pool Culex sp. 1 6 Mesoylops nnultus Trnsient freshwter ponds O. lifsitus Culex sp. 1 1 Diylops uruguyensis Trnsient freshwter ponds O. lifsitus Prylops sp. Etoylops ruesens Artifiil ontiner permnent pool, Eryngium rere, dith nd rie field Permnent pool, dith, Eryngium rere Culex sp. C. pipiens C. rentoi A. litrsis A. egypti C. pipiens C. rentoi Culex sp. 1 1 Euylops sp. Permnent pool Culex sp. 1 lso olleted, ut these speies did not prey upon Culex sp. lrve. Two opepod speies, Prylops sp. nd E. ruesens, ourred in dithes together with C. pipiens, ut they were not lrvivorous. In the rie field we olleted Anopheles litrsis Lynh Arrilzg nd Culex sp., whih shred this hitt with A. roustus, M. lidus, E. ruesens, Euylops sp. nd Miroylops sp. Only A. roustus nd M. lidus were predtors of oth mosquito speies. Prylops sp. ws the only opepod olleted in rtifiil ontiners, ut no predtion ws deteted on lrve of A. egypti nd C. pipiens living in the sme ontiner. Two opepod speies, Prylops sp. nd E. ruesens, were found in the wter-filled xils of E. rere. Both opepod speies were not le to kill Culex rentoi (Lne nd Rmllo), the only mosquito found reeding in this hitt. Lortory predtion tests: The opepod speies seleted for predtion trils were A. roustus, D. uruguyensis, M. lidus nd M. longisetus. M. mendoinus ws not tested euse it ws not possile to reed this speies under lortory onditions. Predtion pity ws oserved in femles nd mles of A. roustus nd D. uruguyensis, ut this pity ws not deteted in lte opepodids (Tle 2). Both speies fed on erly instr A. egypti nd C. pipiens (Tle 3). The omprison of men numer of lrve (ll instrs) of oth mosquito speies onsumed y A. roustus showed tht lrvl instr ws the only highly signifint effet (two-wy ANOVA: F= 7.39; df= 3, 64; p<.), eing non-signifint (p>.) the min effet of prey speies nd the intertion term. Post ho omprisons mong mens resulted in three groups: 2 nd instr A. egypti plus 3 rd nd 4 th instrs of oth speies, 2 nd nd 3 rd instr A. egypti nd C. pipiens, nd 1 st instr A. egypti nd C. pipiens (Fig. 1A). In ontrst, for D. uruguyensis the min effets of oth prey speies (F=.73; df= 1, 64; p=.19) nd lrvl instr (F= 99.3; df= 3, 162 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN ) Vol. 7 (4): , Deemer 29

6 TABLE 2 Predtory pity of dults nd opepodids of four opepods speies on first instr lrve of Aedes egypti (A) nd Culex pipiens (Cp) Predtory pity (%) Femle Mle Copepodids A Cp A Cp A Cp Mesoylops longisetus Mroylops lidus Diylops uruguyensis Anthoylops roustus TABLE 3 Predtion y four opepod speies on eh lrvl instr of Aedes egypti (A) nd Culex pipiens (Cp) lrve in lortory onditions. Eh ell shows men (+ 1 SE) of numer of lrve ded fter 24 h of exposure in three replite eker Killed lrve (n) Copepod speies 1st. instr 2nd. instr 3rd. instr 4th. instr A Cp A Cp A Cp A Cp M. longisetus 14.±1.4 12±1. 6.6±1 7±1 3.6±.8 3.1±1 1±1 1.33±.7 M. lidus 12.8± ±1.3 7±1 1.7± ± ±1.3.±..7±.4 D. uruguyensis.6± ±1 4.1±.68 ±1..4±. A. roustus.33± ±2 3.33±.7 3±1.2.6±.7.6±. Men ± SE predted lrve A C. pipiens A. egypti d d d d B Men ± SE predted lrve C D d d d d I II III IV I II III IV Lrvl instr Lrvl instr Fig. 1. Predtion y (A) A. roustus, (B) D. uruguyensis, (C) M. lidus nd (D) M. longisetus on instrs I to IV of A. egypti nd C. pipiens. Mens with different letters re signifintly different fter Dunn s test (p<.). Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN ) Vol. 7 (4): , Deemer

7 64; p<.) were signifint, wheres intertion ws non-signifint (F= 2.; df= 3, 64; p=.66). Comprisons mong mens showed four homogeneous groups: 3 rd nd 4 th instr C. pipiens nd A. egypti, 2 nd instr A. egypti, 2 nd instr C. pipiens, nd 1 st instrs of oth mosquito speies (Fig. 1B). A. roustus yielded n overll lrvl mortlity of 17% for A. egypti nd 2% for C. pipiens. D. uruguyensis onsumed 21.% A. egypti nd 28% C. pipiens lrve. Differenes in dily mortlity were not signifint ross dys of the experiment (p>.). Thus, dily mortlity during five dys ws onstnt (Figs. 2 nd 3). A. roustus preyed upon A. egypti nd C. pipiens lrve per dy. D. uruguyensis preyed upon A. egypti nd C. pipiens lrve per dy. Differenes were not signifint etween men numers of killed lrve of C. pipiens nd A. egypti when exposed to one A. roustus or D. uruguyensis femle opepod in the sme ontiner. When predtion y M. lidus on eh instr nd prey speies ws ompred, twowy ANOVA showed tht the effets of prey speies (F= 23.6 df= 1, 64, p<.) nd lrvl instr (F= 213.3; df= 3, 64; p<.), s well s their intertion (F= 22.; df= 3, 64; p<.), were highly signifint. Dunn s test showed four groups of mens: 3 rd nd 4 th instrs of C. pipiens nd A. egypti, 2 nd instr A. egypti, 2 nd instr C. pipiens nd 1 st lrvl instrs of C. pipiens nd A. egypti (Fig. 1C). Adult mles hve predtory pity, ut the ltter ws not oserved in opepodids (Tle 2). No differenes in mortlity rtes mong mosquito speies were found when exposed to one opepod in the sme ontiner (p>.). Totl mortlity verged 29.7% for A. egypti nd 24.4% for C. pipiens. The predtory effetiveness of M. lidus ginst erly A. egypti lrve deresed ross the five dys of the experiment. The mximum lrvl mortlity ws reorded on the first dy ( lrve), nd there were signifint differenes ross dys when mortlity ws ompred long the five dys of the tril (F= 4.13; df= 4, 4; p=.64) (Fig. 4). Men ± SE onsumed lrve 1 1 A. egypti C. pipiens Length of exposure (dys) Fig. 2. Predtion y D. uruguyensis on A. egypti nd C. pipiens first instrs during five dys. Mens re not signifintly different (p<.). Men ± SE onsumed lrve 1 1 A. egypti C. pipiens Length of exposure (dys) Fig. 3. Predtion y A. roustus on A. egypti nd C. pipiens first instrs during five dys. Mens re not signifintly different (p<.). Men ± SE onsumed lrve 1 1 A. egypti C. pipiens Length of exposure (dys) Fig. 4. Predtion y M. lidus on A. egypti nd C. pipiens first instrs during five dys. Mens with different letters re signifintly different fter Dunn s test (p<.). 164 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN ) Vol. 7 (4): , Deemer 29

8 Adult femles of M. longisetus preyed on oth mosquitoes speies. ANOVA showed tht the min effet of prey instr ws highly signifint (F= ; df= 3, 64; p<.) ut neither the effet of prey speies nor the intertion (prey speies x lrvl instr) were signifint (p<.). Post ho omprisons showed signifint differenes mong three groups of mens for oth mosquito speies: 3 rd nd 4 th instr, 2 nd instr, nd 1 st instr (Fig. 1D). Mortlity verged 38% for A. egypti lrve nd 39.% for C. pipiens. Adult mles nd lte opepodids lso showed killing pity, lthough the men numer of lrve they preyed upon ws lower (Tle 2). The omprison of predtory effetiveness of M. longisetus on C. pipiens nd A. egypti living in the sme ontiner showed no signifint differenes in predtion rtes (F=.68; df= 1; p=.476). The men dily numer of erly instr lrve onsumed y one M. longisetus femle during five dys ws for C. pipiens nd for A. egypti. M. longisetus onsumed A. egypti lrve, nd C. pipiens lrve in the first dy (Fig. ). Signifint differenes were deteted etween the first dy of exposure nd the following dys (F= 19.11; df= 4, 4; p=.3), thus predtion ws not onstnt during the tril period. Copepod tolerne to desition: No mortlity ws reorded for A. roustus during the experiment. D. uruguyensis showed 1% survivl fter 1 dys, nd 9% (n= 4) fter 3 dys. Eighty perent of M. longisetus (n= 4) survived fter 1 dys nd 6% (n= 3) fter 3 dys in this tril. Mortlity of M. lidus ws 1% (n= ) fter 1 dys. Copepod mortlity ws null in ontiners holding wter throughout the experiment. Copepod tolerne to wter from rtifiil ontiners: No mortlity ourred in A. roustus kept in wter from flower vses during 7, 14 nd 21 dys. For D. uruguyensis the mortlity rte ws 2% fter 14 dys, nd 4% fter 21 dys. For M. longisetus kept in ontiners with wter from emetery vses, Men ± SE onsumed lrve 1 1 A. egypti C. pipiens Length of exposure (dys) Fig.. Predtion y M. longisetus on A. egypti nd C. pipiens first instrs during five dys. Mens with different letters re signifintly different fter Dunn s test (p<.). 2% mortlity ws oserved fter 14 dys. M. lidus showed 4% mortlity fter 14 dys nd this perentge ws mintined until dy 21. No mortlity ws deteted in ny opepod speies red in dehlorinted tp wter. DISCUSSION The most diverse nturl ssemly of lrvivorous ylopoids ws found in permnent pools from the study re, wheres only two predtor opepod speies were found in trnsient freshwter ponds. This ws not unexpeted euse in generl, more stle hitts re more diverse in terms of numer of speies, ompred to hitts sujet to flututions (Connell nd Oris 1964). The ontriution of predtion y memers of this ssemlge to the overll mosquito lrvl mortlity is unknown, nd is worthy of omplementry reserh in field onditions. No lrvivorous opepods were found in rtifiil ontiners nd dringe dithes, whih re the min reeding hitts for A. egypti nd C. pipiens. This sene might e explined euse the prtiulr hrteristis of these mn-mde hitts, suh s their isoltion from other wter odies, mke it diffiult for opepods to gin ess to them. The opepods E. ruesens, Euylops sp., Miroylops sp., nd Prylops sp. did not onsume mosquito lrve under lortory Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN ) Vol. 7 (4): , Deemer 29 16

9 onditions, so they were disrded from further trils. Their low predtory pity n e explined y the smll size of these speies (Mrten nd Reid 27). The lol speies A. roustus, D. uruguyensis, M. lidus, nd M. longisetus showed predtory pity upon mosquito lrve, nd onsequently were seleted for further investigtion. A. roustus nd D. uruguyensis were less effetive predtors on mosquito lrve thn M. lidus nd M. longisetus. These four opepod speies preyed minly on erly instr lrve. The lmost null predtory pity upon older lrve ws not surprising, onsidering tht opepod ylopoids re generlly not lrge enough to kill third nd fourth instr mosquito lrve. Low predtion rtes of opepods on lte instr mosquito lrve hs een reported y previous uthors (Mrten et l. 1989, 1994, Shreier et l. 1996, Mnrique-Side et l. 1998, Soumre et l. 24). The predtory pity of dult femle opepods of the studied speies ws higher thn tht of dult mles nd opepodids, perhps due to their lrger size, nd/or higher moility or ggressive ehvior. We did not find ny predtory preferenes of opepods for either of the tested mosquito speies, A. egypti or C. pipiens. Our results re not in greement with those reported y Miieli et l. (22), who found tht M. nnultus preyed preferentilly on lrve of A. egypti ompred to those of C. pipiens. A preferene of this opepod for speifi prey ws lso found y Soumre et l. (24) in lortory studies of M. longisetus dults, using Aedes lopitus Skuse nd Culex quinquefsitus Sy lrve s prey. In our experiments we did not oserve differentil ttk rte mong preys, perhps due to the smll size of our experimentl ontiners. Any differentil response of prey items ould e nelled y fored, extremely short distne etween individul predtor nd preys, determined y the size of our experimentl ontiner. D. uruguyensis is known from Uruguy nd Brzil (Reid 1998) nd hs reently een found in Argentin (Menu-Mrque, personl ommunition). Results for this speies re novel euse it hs not een studied efore s mosquito predtor. Our results on the predtory pity of D. uruguyensis were similr to those of other studies on ongeneri speies (Mrten et l. 1989, Mrten 1989, 199, 199, Andredis nd Gere 1992). Given tht D. uruguyensis inhits ephemerl pools, its pity to survive dry onditions is not surprising. However, the reltively high mortlity reorded for this opepod speies in wter from flower vses redues the possiility of using it for the ontrol of mosquitoes reeding in smll humn-mde ontiners. A. roustus is Neotropil opepod (Menu-Mrque 21) tht showed predtory pity similr to tht oserved in Anthoylops vernlis Fisher. Previous studies hve demonstrted tht A. vernlis feeds only on first instr mosquito lrve under lortory onditions (Mrten 1989, 199, Andredis nd Gere 1992). In this work, we show tht A. roustus is n effiient predtor nd n lso survive oth under desition onditions nd in wter from rtifiil ontiners. M. longisetus is Neotropil ylopoid tht hs een reported to redue lrvl popultions of Anopheles limnus Wiedemnn in rodside dithes (Mrten et l. 1989), s well s A. egypti nd A. lopitus in ontiner hitts (Shreier et l. 1993, Mrten et l. 1994, Mnrique-Side et l. 1998). In our study, M. longisetus showed good level of predtion nd its survivl under desition ws not severely redued during 3 dys. Mehnisms of tolerne to desition hve een oserved in speies of Mesoylops (Zhen et l. 1994). However, Gorrohotegui-Eslnte et l. (1998) reported deresed survivl of M. longisetus during the dry seson in Mexio. Some mortlity ws reorded when M. longisetus ws mintined in wter from flower vses, ut mortlity ws not high enough to rejet this speies s potentil mosquito ontrol in smll ontiners. M. lidus is opepod with worldwide distriution (Menu-Mrque 21). It ws found to e predtor with good killing power, 166 Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN ) Vol. 7 (4): , Deemer 29

10 in greement with previous studies (Mrten 199), ut its inility to survive in dry onditions, plus the high mortlity oserved in the ssys with wter oming from emetery vses, suggest limited effiy ginst C. pipiens nd A. egypti. Furthermore, this speies ould e prtiulrly limited y tempertures exeeding 37 ºC (Mrten et l. 1994), hrteristi tht eomes importnt when onsidering their use s iologil ontrol gent for tropil immture mosquitoes, suh s A. egypti. In onlusion, M. lidus nd M. longisetus show the highest predtion rtes, lthough the ltter re not sustined long five dys. The low resistne to desition of these opepods suggests tht they re less pproprite to e used in smll ontiners in whih stnding wter my e sent for vrile periods. On the other hnd, A. roustus nd D. uruguyensis, lthough they onsume lower numer of prey, re more desition-resistnt, tolerte wter from ontiners, nd their predtion rtes re pproximtely onstnt; onsequently, these speies re interesting predtors to e onsidered for inlusion in the existing lists of lrvl mosquito enemies. ACKNOWLEDGMENTS We re grteful to CONICET (Buenos Aires, Argentin) for prtilly supporting this study (PIP 6) nd Silvin Menu-Mrque for onfirmtion of opepod identity. MCT holds dotorl fellowship from CONICET, Argentin. RESUMEN Se hizo un prospeión de opépodos en L Plt, Argentin, on los ojetivos de rterizr l omunidd lol de opépodos lrvívoros en sitios de rí de mosquitos, e identifir nuevs espeies depreddors de los mosquitos de ontenedores rtifiiles Aedes egypti y Culex pipiens. L diversidd de ilopoides lrvívoros fue máxim en hros permnentes. Se exminó l depredión por sexos y edd, l seletividd por espeies de mosquito, y l ts de depredión diri durnte ino dís en Anthoylops roustus, Diylops uruguyensis, Mroylops lidus y Mesoylops longisetus. Los opépodos hemr presentron l pidd depreddor más lt. No se enontró prefereni por lgun espeie de mosquito. De uerdo l potenil de depredión en generl, los opépodos se ordenn sí: D. uruguyensis < A. roustus < M. lidus < M. longisetus. Tmién se evluó l tolerni l deseión del háitt y l pidd de resistir en gu de ontenedores rtifiiles. D. uruguyensis y A. roustus sorevivieron en ondiiones de sequí, pero D. uruguyensis presentó menor superviveni en gu de floreros de ementerio. M. lidus no sorevivió ondiiones de sequí y no toleró el gu extríd de ontenedores rtifiiles. Los ilopoides neotropiles D. uruguyensis nd A. roustus son uenos ndidtos y mereen investigión ulterior omo gentes de ontrol iológio de mosquitos. Plrs lve: opépodos, mosquitos, depredión lrvl, ontrol iológio, Argentin. REFERENCES Andredis, T.G. & M.A. Gere Lortory evlution of Anthoylops vernlis (Thomsi) (Copepod: Cylopoide) s predtors of Aedes ndiensis nd Aedes stimulns (Dipter: Culiide). J. Med. Entomol. 29: Brown, M.D., B.H. Ky & J.K. Hendrikz Evlution of Austrlin Mesoylops (Cylopoide: Cylopoide) for mosquito ontrol. J. Med. Entomol. 28: Connell, J.H. & E. Oris The eologil regultion of speies diversity. Amer. Nt. 98: Drsie, R.F Mosquitoes of Argentin. Prt I. Keys for identifition of dult femles nd fourth stges lrve in English nd Spnish (Dipter: Culiide). Mosq. Syst. 17: Gorrohotegui-Eslnte, N., I. Fernndez-Sls & H. Gomez-Dnte Field evlution of Mesoylops longisetus (Copepod: Cylopoide) for the ontrol of lrvl Aedes egypti (Dipter: Culiide) in Northestern Mexio. J. Med. Entomol. 3: Lne, J Neotropil Culiide. F. Hyg. Sude Pul. Univ. São Pulo 2: Mnrique-Side, P., S. Iñez-Bernl, H. Delfín-González & V. Prr Mesoylops longisetus effets on survivorship of Aedes egypti immture stges in r tyres. Med. Vet. Entomol. 12: Mrten, G.G A survey of ylopoid opepods for ontrol of Aedes lopitus lrve. Bull. So. Vetor Eol. 14: Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN ) Vol. 7 (4): , Deemer

11 Mrten, G.G Evlution of ylopoid opepods for Aedes lopitus ontrol in tires. J. Am. Mosq. Control Asso. 6: Mrten, G.G Elimintion of Aedes lopitus from tire piles y introduing Mroylops lidus (Copepod, Cylopoide). J. Am. Mosq. Control Asso. 6: Mrten, G.G., R. Astiz, M.F. Surez, C. Monje & J.W. Reid Nturl ontrol of lrvl Anopheles limnus (Dipter: Culiide) y the predtor Mesoylops (Copepod: Cylopoid). J. Med. Entomol. 26: Mrten, G.G., G. Borjs, M. Cush, E. Fernández & J.W. Reid Control of lrvl Aedes egypti in peridomesti reeding ontiners. J. Med. Entomol. 31: Mrten, G.G. & J.W. Reid. 27. Cylopoid opepods. J. Am. Mosq. Control Asso. 23: Mrti, G.A., M.V. Miieli, A.C. Sorsetti, & G. Liljesthrom. 24. Evlution of Mesoylops nnultus (Copepod: Cylopoide) s ontrol gent of Aedes egypti (Dipter: Culiide) in Argentin. Mem. Inst. Oswldo Cruz 99: 3-4. Menu-Mrque, S. 21. Dtos iogeográfios y nuevs loliddes de opépodos de l Fmili Cylopide (Copepod, Cylopoid) de l Argentin. Physis 8: Miieli, M.V., G.A. Mrti & J.J. Grí. 22. Lortory evlution of Mesoylops nnultus (Wierzejski, 1892) (Copepod, Cylopoide) s predtor of ontiner-reeding mosquitoes in Argentin. Mem. Inst. Oswldo Cruz 97: Nm, V.S., N.T. Yen, M. Holynsk, J.W. Reid & B.H. Ky. 2. Ntionl progress in dengue vetor ontrol in Vietnm: Survey for Mesoylops sp. (Copepod), Mironet sp. (Corixide), nd fish s iologil ontrol gents. Am. J. Trop. Med. & Hyg. 62: -1. Reid, J.W Clve de identifiço e list de referenis iliográfis pr s espéies ontinentis sudmerins de vid livre d ordem Cylopoid (Cruste, Copepod). Bol. Zool. Univ. São Pulo 9: Reid, J.W Redesription nd first reords from Brzil of Diylops uruguyensis Kiefer (Cruste, Copepod, Cylopoide). Rev. Brsileir Zool. 1: Ringuelet, R.A Los rustáeos opépodos de ls gus ontinentles de l Repúli Argentin. Sinopsis Sistemáti, Contr. Cient. F. Cien. Ex. Nt. Univ. B. Aires, Zool. 1: Riviere, F., B.H. Ky, J.M. Klein & Y. Sehn Mesoylops speriornis (Copepod) nd Billus thuringiensis vr. isrelensis for the iologil ontrol of Aedes nd Culex vetors (Dipter: Culiide) reeding in r holes, tree holes, nd rtifiil ontiners. J. Med. Entomol. 24: Shreier, E.T., C.F. Hllmon, K.M. Eskridge & G.G. Mrten Effets of Mesoylops longisetus (Copepod: Cylopoide) on mosquitoes tht inhit tires: influene of litter type, qulity nd quntity. Am. J. Trop. Med. & Hyg. 12: Shreier, E.T., W.L. Turner, A.M. Lopez, C.F. Hllmon & G.G. Mrten Evlution of two ylopoid opepods for Aedes lopitus ontrol in tires in the pnhndle of Florid t low introdution rtes. J. Fl. Mosq. Control Asso. 64: Sokl, R.R. & F.J. Rohlf Bioestdísti. Prinipios y Métodos Estdístios en l investigión iológi. Blume, Buenos Aires, Argentin. Soumre, M.K., J.E. Cilek & E.T. Shreier. 24. Prey nd size preferene of Mesoylops longisetus (Copepod) for Aedes lopitus nd Culex quinquefsitus lrve. J. Am. Mosq. Control Asso. 2: Surez, M.F., D. Ayl, M.J. Nelson & J.W. Reid Hllzgo de Mesoylops speriornis (Ddy) (Copepod: Cylopoide) depreddor de lrvs de Aedes egypti en Anpoim, Colomi. Biomédi 4: Zhen, T., C.D. Jenning & B.H. Ky Lortory studies of desition resistne in Mesoylops (Copepod: Cylopoid). J. Am. Mosq. Control Asso. 1: Rev. Biol. Trop. (Int. J. Trop. Biol. ISSN ) Vol. 7 (4): , Deemer 29