LOCATION OE FINIANDICUS (: ) ON LEAVES OF FAGUS SYLVATICA

J. Kabíček

Czech University of Agriculture, Faculty of Agrobiology, Food and Natural Resources, Prague, Czech Republic

Phytoseiid mtte Euseius finlandicus was sampled from leaves of beech Fagus sylvatica planted in urban green areas. The accurate iocations of E..finlnndicus on the leaf undersurfaces were recorded. 125 specimens in total of E.finlandicu,t were collected from leaves of F. sylvatica. The population density of this mite species averaged 1.04 mites per leaf on investigated F. sylvatica trees. Most specimens of E..finlandicus werc captured along tbe raised veins with hairlike trichomes. E.finlandicus was not observed on hairless leaf blades of investigated beech leaves. Some specimens (70.4Vo of all sampled motile stages) were found within tuft domatia. The raised veins with long hairlike trichomes the most preferred leaf surface microhabitat by the both motiie immature and adult stages of E. finlandicus on leaves of F. syl.vatica. This vein microhabitat can be used for shelter and the rest by E. finlandicus on beech leaves. Leaf surface structures together with type of defensive strategy before macropredators influenced the occuÍTence of E. finlandiclls within leaf microhabitats on beech leaves.

Euseius finlandicus; Fagus sylvatica; leaf microhabitat; defensive strategy; Phytoseiidae; Acari

TNTRODUCTION green in Prague in 2002 and 2003. Leaves were sampled from branches 2-3 m above the ground. A total of Predatory mites of the family Phytoseiidae are known 120 leaves was collected. The beech trees were identified as important natural enemies of small includ- using the key of Dostál (1954). The packed samples ing various phytophagous tetranychid and eriophyid mite in plastic bags were placed and cooled in the portable species. Many phytoseiid species are used as effective storage box and brought to the laboratory where they predators in integrated pest management programs to were either examined immediately or stored in the refrig- control agriculturally important pests in many crops erator at 5 "C for <24 h before examination. (Huff aker et al., 1970; McMurtry et a1.,1970). Cooled leaves were inspected individually for phyto- In natural habitats, some phytoseiids are important in seiids in the laboratory using a stereomicroscope. The preventing outbreaks of various phytophagous mites underside of each leaf was divided into three microhabi- (Edland, Evans, 1998). These predaceous mite tats - veins, domatia and the leaf blade. The mites oc- species often inhabit the leaves of deciduous tree and curring nearby domatia (veins) within the two-fold mite shrub species. body length distance were included into the domatia The local ecology of phytoseiids is influenced (vein) microhabitat. The accurate positions and numbers strongly by leaf morphology (Beard, Walter, of motile stages of phytoseiids per each leaf microhabitat 2001). Various structures on leaf undersurfaces (raised were recorded. Observations were made on the entire leaf veins, density of hairs, domatia) affect searching. mating. surface. Mite densities were expressed as the number of oviposition, and other behaviors of these predatory mites motile stages per leaf. The phytoseiid mites were sepa- (Krei ter,2002). The numbers of phytoseiids are af- rated from leaves by using insect pins, and than trans- fected by the density and locations of hair, bristles, and ferred directly into lactic acid. After clearing in lactic pockets on the leaf surfaces (Karban et a1., 1995). acid, mites were mounted in Swann medium on micro- Leaves with domatia have more mites than leaves with- scope slides. The mites were identified using the keys of out them (Wa1 ter, O' D o w d,, 1992). Beglyarov (1981a, b). The mite Euseius finlandicus (Oudemans, 1929) is a common phytoseiid species on broad leaf trees in Bo- hemia (Kab íček' 2000). The subject of this study was RESULTS AND DISCUSSION to investigate the presence and location of the phytoseiid mite E finlandicus on leaves of Fagus sylvatica. A total of I25 specimens of E. finlandlcr.ls was found on leaf undersurfaces of F. sylvatica. This mite species occuÍTed on almost 5lvo of allsampled leaves. The popu- MATERIAL AND METHODS lation density of E. finlandicus averaged 1.04 mites per beech leaf. Leaf samples (one sample = ten haphazardly selected Both immature and adult stages of this phytoseiid spe- leaves per tree of approximately identical size) were cies were most abundant aiong the raised veins with hair- taken from trees of Fagus sylvatica planted in urban like trichomes (Table 1). Most of non-moving and non-

SCIENTIA AGRICULTURAE BOHEMICA' .jó. 2005 (.1): 21 _29 27 ieaves of F' syLvatica able The distribution of E..fintant)icus on (7o) ToÍa]. (?o) (7o) Males (4o\ Larvae, nYmfae Leaf microhabítat Females 89.6 85.0 87.1 Veins 95.3 10.4 15.0 12.9 Domatia 4.1 0.0 0.0 0.0 Leaí blade 0.0

raised CONCLUSION moulting specimens of E. finlandic&s inhabited the specimens were found nearby the mid-ribs and some show that leaf mi- leaves' too' By The results obtained by this study large raised subsidiary veins of beech by E' E' crohabitats with trichomes were preferred fin- .oir.ur,, Ch ant (1959) reported that finlandicus of and landicus on beech leaves' Frequency of occurrence was uniformly distributed over the lower surface E' leaf' E' non-moving and non-moulting specimens of fin- showed no preference for any part of the apple along the raised veins with numerous trichomes is the generalist mite predator that mostly landicus "f.edsfinlandicus this leaf microhabitat can be used for shel- r y C r o f t 1991; J u n g indicates that on pollen (M c M u r t , , ' leaves' ter and rest by this phytoseiid species on beech Crof t, 2001) and vertical leaf hairs on the undersur- veins with long hairlike trichomes were the used for oviposition by this mite spe- The raised faces of leaves are by the both mo- sheltered most preferred leaf surface microhabitat 1 is known that various cies (C h a n t , 959). It on leaves the tile immature and adult stages of E'lnlandicus habitats rather than food availability may limit ieaf surface StructuÍes together with the phytoseiid mites on plants (Tuovinen' of F. sylvatica.Leaf numbers of influenced the occurrence of et al', 1995)' The presence' typ" oi defensive strategy Rokx , 1991; Karban on beech leaves' of f,. within leaf microhabitats density and distribution of hairs on the underside ftnlandtcus of E' beech leaves may explain the frequent occurrence nearby the raised veins with numerous long fLnlandicus of REFERENCES irichomes on investigated leaves' The distribution and non-moulting specimens of E' fi'- non-moving G' H': Host plant specificity in leaves indicates that the BEARD. J. J. - WALTER, Iandicus on examined beech Ento- several species of generalist mite predators Ecol' raised veins with hairlike trichomes are the most pre- mite for mol., 26, 2001 : 562-5'7 0' ferred leaf microhabitat used by this phytoseiid BEGLYAROV, G. A.: Opredelitel chishchnych kleshchej fi- shelter and rest, too. (Parasit:iformes. Phytoseiidae) fauny SSSR' Infor' not occur on hairless leaf blades of toseiid E. finlandicus did (ln Russian) (10'47o alt Byull. VPS MOBB, 2, 1981a: 1-95' inspeěted beech leaves. Some specimens of A.: Opredelitel chishchnych kleshchej fi- phytoseiid species were found in BEGLYAROV, G. sampled stages) of this SSSR' lnfor' en- toseiid (Parasitiformes, Phytoseiidae) fauny tuft domatia (Table 1). These specialized structures Byull. VPS MOBB, -1, 1981b: l-45' (In Russian) minute spaces on the leaf undersurface usually 1o- close mites (Acarina: Phytoseiidae)' vein axils (O'Dowd, Willson' CHANT, D. A.: Phytoseiid cated in major southeastern Eng- spe- Part I. Bionomics of seven species in 1997). Typically predaceous and fungivorous mite Suppl' 12, 91 1959: 1-44' structures for shelter and breeding land. Can- Entomol', ' cies use these ČsR (rne key to the (O'Dowd, Willson' 1989; Pemberton' DOSTÁL, J.: Klíčk úpinékvěteně flora of the Czech Republic)' Praha' Nakladatel- Turner,1989). complete SNí ČsAv 1954. 1183 pp. The most specimens of E' finlandicus moved rapidly EVANS, G' O': The genus Typhlodromus leaf blade when disturbed within EDLAND. T. - over the hairless beech Entomol" 95' (1994) (Acari: ) in Norway' Eur' J' the vein or domatia microhabitats' Tuovinen was very 1998:2'75-295. reported that E. finlandicus moved quickly and HUFFAKER. C. B. VAN DE VRIE' M' - McMURTRY' on apple leaves. According to Ch anÍ 0959) E' - ujiu" populations and their possible control ioamed freely over apple leaf surfaces and J. A.: Tetranychid fínlandicui an evaluation' Hilgardia' 40' 19'70:391-458' over appie leaf when disturbed or even by predators: moved rapidly and aerial dispersal a method of rapid JUNG, C. - CROFT, B. A': Ambulatory undisturbed. E. fintandicu.s evolved (Acari: among specialist and generalist predatory mites escape before macropredators that depends on speed Entomol', -30' 200i: I 1 12-1i 18' This defensive strategy together with Phytoseiidae). Environ' (Chant, 1959). foliage of deciduous of the KABÍČEK'J.: Phytoseiid mites on the leaf surÍace Structures may explain the preference woody plants. ln: Proc' XVth Czech and Siovak Plant microhabitat by this phytoseiid species on ex- leaf vein 358-359' vein microhabitat used by Protection Conf., Brno, 2000: amined beech leaves. Leaf _ M' A' rest and KARBAN, R. - ENGLISH-LOEB. G. WALKER' - most specime ns of E. finlandicus for shelter and THALER' J.: Abundance of phytoseiid mites on Vilis spe- glabrous leaf blade microhabitat on leaves of F ' sylvatica cies:effectsofleafhairs,domatia,preyabundanceandplant állow them better to utilize their defensive strategy de- phylogeny. Exper. Appi' Acarol" 19' 1995: 189-197 ' pending on rapid escape before macropredators'

(1):21_29 SCIENTIA AGR]CULTURAE BOHEMICA ' 3ó'2005 KREITER, S. _ TIXIER, M. S. _ CROFT, B. A. - AUGER, deciduous forest in Wisconsin. Amer. Midl. Natur., 1.t7, P. - BARRET. D.: Plants and leaf characteristics influenc- 199'7:33'7-348. ing the predaceous mite Kampimodromus aberrans PEMBERTON. R. W. - TURNER. C. E.: Occurrence of (Acari: Phytoseiidae) in habitats surrounding vineyards. predatory and fungivorous mites in leaf domatia. Amer. J. Environ. Entomol.' 31 , 2002: 648_6ó0. BoÍ', 76, 1989: l05-l 12. McMURTRY, J. A. - CROFT, B. A.: Life styles of phyto- TUOVINEN, T.: lnfluence of surrounding trees and bushes seiid mites and their roles in biological control. Ann. Rev. on the phytoseiid mite fauna on apple orchard trees in Entomol. 42. 199'7 : 291-321. Finland. Agriculture, Ecosystems & Environment, 50, McMURTRY. J. A. - HUFFAKER, C. B. - VAN DE VRIE, 1994: 39-47. M.: Tetranychid enemies: their biological characters and TUOVINEN, T. - ROKX, J. A. H.: Phytoseiid mites (Acari: the impact of spray practices. Hilgardia, 40, 1970 331- Phytoseiidae) on apple trees and in surrounding vegetation 389. in southern Finland. Densities and species composition. O'DOWD. D. J. - WLLSON. M. F.: Leaf domatia and mites Exp. App1. Acarol., 12. 1991: 35-46. on Australasian plants: ecological and evolutionary impli- WALTER. D. E. - O'DOWD. D. J.: Leaves with domatia cations. Biol. J. Linn. Soc., 37,1989: 191-236. have more mites. Ecology, 7 j, 1992: 1514-1-51 8. O'DOWD, D. J. - WILLSON, M. F.: Leaf domatia and the distribution and abundance of foliar mites in broadleaf Received for publication on December 20,2004 Accepted for publication on January 20,2005

KABÍČEK,J. (Česká Zemědělská univerzita, Fakulta agrobiologie, potfavinových a přírodních zdrojů, Praha, Česká republika): Rozmístění Euseius finlandicus (Acari: Phytoseiidae) na listech Fagus sylvatica. Scientia Agric. Bohem ., 36, 2005: 21-29.

V průběhu dvou let byl sledován výskyt a rozmístění roztočůčeledi Phytoseiidae na listech buků Fagus sylvatica rostoucích v městském lese. Listy pfibliŽně stejné velikosti byly odebírány náhodně z větví do výšky dvou aŽ tří metrů. Spodní strana listu byla z hlediska výskytu roztočůrozdělena na tři mikrohabitaty: žilky, domatia a listová čepel. Na rubu sledovaných listů bylo nalezeno celkem 125 jedinců roztoče Euseius finlandicus, v průměru 1,04 roztoče na list' Yíce neŽ 89 7o iedjnců bylo odchyceno v těsné blízkosti výrazně vystouplých žilek porostlých dlouhými rovnými trichomy' ostatní jedinci (necelých 11ok) byli nalezeni v domatiích tvořených překrývajícími se trichomy v paŽdí Žilek. Na zbývajícíchlysých částech listových čepelínebyl Zj1šÍěn Žádný roztoč E. finlandicus.PÍevaŽující nálezy dospělců a pohyblivých vývojových stadií roztoče E. ftnlandicus v blízkosti Žilek svědčí o výrazné preferenci tohoto mikrohabitatu tímto roztočem. Četny výskyt nepohybujících Se a nesvlékajícíchse jedinců E. finlandicus v blízkosti Žilek indikuje vyuŽívání tohoto mikrohabitatu jako místa pro úkryt a odpočinek. Listové Struktury a typ obranné Strategie před makropredátory ovlivňovaly výskyt roztoče E. fi.nlandicus v mikrohabitatech listů buku Fagzs sylvatica.

Euseius Jinlandicus; Fagus sylvatlca,' listový mikrohabitat; obranná strategie; Phytoseiidae] Acari

Contact Address:

RNDr. Jan Kabíček,CSc., Česká zeměděIská univerzita v Praze, Fakulta agrobioiogie, potravinových a pffrodních zdrojů' Kamýcká ),29, 165 2l Praha 6-Suchdol. Česká republika, tel.: +42O 224 382 682, fax'. +42O 22O 921 649, e-matl kabicek @ af.czu.cz

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