Plant galls and gall midges (Diptera: Cecidomyiidae) of the Faroe Islands in the Atlantic Ocean Plantuvølir og vølamíggj (Diptera: Cecidomyiidae) í Føroyum Marcela Skuhravá and Václav Skuhravý Bítovská 1227, CZ 140 00 Praha 4, Czech Republic, Email: [email protected] plantuni; og tey sløg, ið eru eftir, eru fremmand og eru Úrtak vorðin innslødd til Føroya við fólki. Frá einum lívfrøði- Tíggju vølelvandi og vølatknýttar lívverur, ið komu fyri landafrøðiligum sjónarmiði eru Oligotrophus juniperi- á sjey vertsplantusløgum, ið hoyrdu til sjey plantuættir, nus, Contarinia floriperda, Aceria pseudoplatani og vórðu funnar nærindis Tórshavn í august 2005. Av Aculus anthobius evropisk sløg, Mycodiplosis melamp- teimum eru fimm sløg vølamíggj (Cecidomyiidae, Dip- sorae og Clinodiplosis cilicrus eru evro-sibirisk sløg og tera), tvey eru eriophyid-mottur (Eriophyioidea, Feltiella acarisuga er eitt alheimsslag. Finningurin av C. Acarina) og trý hoyra til ymsar soppaættir. Allir finn- floriperda í Føroyum er tann norðasta fyrikomingin í ingar eru nýggjar skrásetingar í Føroyum. Sjey sløg elva Evropa. Tað lága talið á sløgum av vølelvandi lívverum til vølir á ymsum vertsplantum, nevniliga Cecido- í Føroyum kemst av landafrøðiligari avbyrging og nat- myiidae, Oligotrophus juniperinus, ið elvir til knubba- úrligum umstøðum í landinum, t.e. heldur lítil gróður vølir á vanligum baraldi, Juniperus communis, og og trot á trøum og runnum, sum kundu verið møgu- Contarinia floriperda, ið elvir til blómuknubbavølir á ligar vertsplantur hjá vølelvandi lívverum. einum slag av royniviði, Sorbus aria; Eriophyoidea, Aceria pseudoplatani, á bløð á einum slag av ahorn, Abstract Acer pseudoplatanus, og Aculus anthobius á stelk og Ten gall-causing and gall-associated organisms occur- blómur á einum slag av steinbrá, Galium anisophyllum; ring on seven host plant species belonging to seven og soppurin Cronartium ribicola, ið elvir til vølir á bløð plant families were found near Tórshavn on the island á sólberjarunni, Ribes nigrum, og Melampsora caprea- of Streymoy, one of the Faroe Islands, in August 2005. rum á bløð á pálmapíli, Salix phylicifolia, og Puccinia Of these, five species are gall midges (Cecidomyiidae, violae á bløð á dimmari blákollu, Viola riviniana. Trý Diptera), two are eriophyid mites (Eriophyioidea, vølamíggj, ið ikki elva til vølir, eru knýtt at vølelvandi Acarina) and three belong to various families of fungi. lívverum, nevniliga Mycodiplosis melampsorae og All findings are new records for the Faroe Islands. Seven Clinodiplosis cilicrus, bæði planturotátin (phytosapro- species cause galls on various host plants, namely the phagous) sløg, ið eru knýtt at rotnum plantutilfari, og Cecidomyiidae, Oligotrophus juniperinus causing bud Feltiella acarisuga, eitt djóraátið (zoophagous) slag, ið galls on Juniperus communis and Contarinia floriperda gagnnýtir tetranychid-mottur. Oligotrophus junipe- inducing flower bud galls on Sorbus aria; the Erio- rinus, Contarinia floriperda og Puccinia violae eru upp- phyoidea, Aceria pseudoplatani on leaves of Acer runalig í Føroyum í sambandi við upprunan at verts- pseudoplatanus and Aculus anthobius on stems and Fróðskaparrit 57. bók 2009 115-127 116 PLANT GALLS AND GALL MIDGES OF THE FAROE ISLANDS IN THE ATLANTIC OCEAN flowers of Galium anisophyllum; and the fungi ently many times during the evolution of in- Cronartium ribicola galling leaves of Ribes nigrum, sects as well as of other groups (Roskam, Melampsora caprearum on leaves of Salix phylicifolia and Puccinia violae on leaves of Viola riviniana. Three 1992). th non-galling gall midges were associated with gall- At the beginning of the 20 century one causing organisms, viz. Mycodiplosis melampsorae and thousand and five hundred gall-causing ani- Clinodiplosis cilicrus, both phytosaprophagous species mals were known in Europe, associated with associated with decaying plant matter, and Feltiella about four thousands host plants (Houard, acarisuga, a zoophagous species preying on tetra- nychid mites. Oligotrophus juniperinus, Contarinia 1908-1909). Cecidology quickly developed th floriperda and Puccinia violae are native to the Faroe and in the second half of the 20 century Islands with regard to the origin of their host plants; about three thousand gall-causing and as- and the remaining species are alien and were intro- sociated organisms were known to occur in duced to the Faroe Islands by man. From the biogeo- Central and Northern Europe (Buhr,1964- graphical point of view Oligotrophus juniperinus, Contarinia floriperda, Aceria pseudoplatani and Aculus 1965). They belong to various groups of or- anthobius are European species, Mycodiplosis melamp- ganisms: about one third to bacteria and sorae and Clinodiplosis cilicrus are Euro-Siberian species fungi, two thirds to animals. Three groups of and Feltiella acarisuga is a cosmopolitan species. The animals are the species richest causers of finding of C. floriperda in the Faroe Islands is the most galls on various plants, viz. the gall midges northern occurrence in Europe. The low species number of gall-causing organisms in the Faroe Islands (Cecidomyiidae, Diptera) with about 600 is the result of geographical isolation and natural con- species, eriophyid mites (Eriophyoidea, Aca- ditions of these islands with relatively poor vegetation rina) with about 350 species and aphids and lack of trees and shrubs, which may be potential (Aphidoidea, Hemiptera) with about 370 host plants of gall-causing organisms. species. Since that time many new species of gall-causing organisms have been discovered and described and the number of these or- ganisms is at present much higher. Introduction Knowledge of galls has a long history. A gall (in Latin „cecidium") is defined as any The famous Italian physician and researcher deviation in the normal pattern of plant Marcello Malpighi (1628-1694), the founder growth produced by a specific reaction to of microscope anatomy, is considered to be the presence and activity of a foreign organ- also the founder of cecidology. In 1679 he ism (animal or plant) (Bloch, 1965). An in- published the comprehensive work „Anato- terdisciplinary scientific discipline at the bor- mes Plantarum" in which he included the der between botany and zoology, directed chapter called „De Gallis" (in English: About to the study of plant galls at all levels, is galls). This chapter is the first scientific ap- named cecidology. Galls caused by animals proach to the study of galls on plants and, are called zoocecidia and animals causing therefore, Malpighi is recognized as the fa- galls are cecidozoa, galls caused by plants are ther of cecidology. Redfern et al. (2008) phytocecidia and such plants are called ce- translated this fundamental work on galls cidophyta. The ability of organisms to in- from Latin to English. The cooperation of duce galls on plants has evolved independ- these three authors makes it possible to be Plantuvølir og vølamíggj (DiPtera: CeCiDomyiiDae) í Føroyum 117 acquainted with admirable work of Marcello lions of years ago, from submarine outpour- Malpighi. ings of basaltic lava, and belong geologically The literature on galls is very extensive. to the North Atlantic Basalt Province. Lava Houard (1908-1909) gave a rich bibliography and ashes from volcanic eruptions have including about 1000 references, Mani formed basalt plateaux. Later the glaciers of (1964) in his comprehensive book „The eco- the Glacial Age have transformed it into a logy of plant galls" included 1300 references mountainous group of islands with deep val- that refer to the problem of galls, Buhr leys and narrow fiords. The highest point is (1964-1965) in his two-volume book with 882 m, the average elevation 300 m above identification keys to plant galls gave even sea level. A mild and damp oceanic climate 2700 references. Useful data on biology and prevails owing to the Gulf Stream which ecology of gall causing organisms may be meets a cold polar current deflected from found in books published by Ananthakrish- Iceland. Average temperature in summer is nan (1984), Shorthouse and Rohfritsch 110 C, in winter 30 C. The weather changes (1992), Redfern et al. (2002), Raman et al. very quickly and storms are violet and sud- (2005) and Ozaki et al. (2006). den. Fog, showers and sunshine follows at In the period 1955-2008 we investigated short intervals (Schlei and Moberg, 2003). gall midges and their galls in many countries The natural vegetation is dominated by of Europe at more that 1800 localities arctic-alpine plant species, viz. wild flowers, (Skuhravá and Skuhravy, 1998). In August grasses, mosses and lichens. Most of the 2005 we had an opportunity to spend one lowland is grassland and some heath. Only week in Tórshavn, the capital of the Faroe Is- about 6% of the total area has been culti- lands. We did as it we usually do during our vated. The rest is waste land covered with field trips and excursions in various countries grasses along the seaside and with poor of Europe, and searched for galls on various vegetation in higher country. Above 600 host plants. metres mosses and lichens predominate. About 340 native wild plant species grow in Study area the Faroe Islands (Fosaa, 2000) and about 60 Faroe Islands (Føroyar, Faroes, Færøerne) is introduced species. The natural vegetation is an interesting country. It is a group of 18 is- characterised by lack of wild trees and lands of various size situated in the middle shrubs. In the past birch (Betula spp.) and of the North Atlantic between latitude 610 juniper (Juniperus communis) occurred on 20' N and 620 24' N and longitude 60 15' W islands and their remnants were found in and 70 41' W. They measure from north to peat bogs. Salix herbacea, a native species, is south 113 km, from west to east 75 km and growing in the mountains. Recently various the total land area is 1399 square kilometres. trees and shrubs were introduced and are They are halfway between Iceland and Nor- planted in private gardens around houses. way and the nearest land is Shetland to the Forest plantation, founded in Tórshavn in south-east, about 300 kilometres away.