© Entomologica Fennica. 20 September 1996 Chloroclystis v-ata relicta ssp. n. (Lepidoptera, Geometridae), a new taxon from SW Finland, doomed to go extinct? Harry Krogerus Krogerus, H. 1996: Chloroclystis v-ata relicta ssp. n. (Lepidoptera, Geometridae), a new taxon from SW Finland, doomed to go extinct?-Entomol. Fennica 7:63-66. An isolated population of Chloclystis v-ata (Haworth, 1809), occurring at Karkali Peninsula, a nature reserve in southwestern Finland, is described as a new subspecies, ssp. relicta ssp.n., on the basis of differences in appearence and phenology compared to the nominate subspecies. The Central European population of Ch. v-ata has been expanding to the north, reaching the Baltic Sea area in recent decades and Finland in 1985. Thus, the new subspecies which is actually protected by law is now threatened by hybridization with the nominate subspecies. In contrast to the bivoltine nominate subspecies, the Karkali population is univoltine. The biology of the new subspecies is dis cussed. Harry Krogerus, Bjorneborgsviigen 5 P, F/N-00350 Helsingfors, Finland Received 10 March 1995, accepted 19 October 1995 1. Introduction 1916 (e.g. Juul1948, Fibiger & Svendsen 1981) and in southeastern Estonia in 1940 (Sulcs & In the world, many small populations, or subspe Viidalepp 1972). The species is widespread in the cies or species with restricted distributions, are Palaearctic. It has been recorded from Ireland and in danger of losing their genetic character due to Portugal in the west through central and southern hybridizing with closely related widespread Europe, southern Russia and the Caucasus to Iran, populations of expansive nature (D. Simberloff, India and China, and Siberia, Manchuria, Primorye pers. comm.). and Japan (as ssp. lucinda Butler, 1879) in the east. The geometrid species Chloroclystis v-ata The Karkali Peninsula is characterized by ex (Haworth, 1809) (= Ch. coronata Hubner, 1813) ceptionally rich vegetation with several southern was found for the first time in Finland in 1948. The deciduous trees and many rare plant species. At the first specimen, a male, was collected from a lime collecting site of the first C. v-ata specimen Tilia tree (Tilia) trunk on Karkali Peninsula in Karislojo cordata, Quercus robur, Corylus avellana and (Karjalohja), southwestern Finland. The find was Lonicera xylosteum dominate the tree and bush unexpected as there were only a few records of the layer; the vegetation in the field layer is unique in species from northern Europe. No fmds were known Finnish conditions with plants like Mercurialis, from Sweden or Denmark. The species was, how Actaea, Pulmonaria, Viola mirabilis and Milium. ever, recorded at Oslo-fjord in southern Norway in The area was declared a nature reserve in 1961. 64 Krogerus: Chloroclystis v-ata relicta ssp. n. • ENTOMOL. FENNICA Vol. 7 2. Observations and expansion in more Diagnosis. The ssp. relicta differs externally southern areas from the nominate subspecies by its smaller size (see below), paler bluish-green ground colour of Monitoring during 1950-1993 has shown thatCh. forewing with silky sheen that is absent in the v-ata has a permanent population in the Karkali nominate subspecies, and weaker wing pattern. The Peninsula. The area occupied by the population is, pale subterminal line, clearly visible in the nomi however, only about three hectares along a SW nate form, is absent or very indistinctly marked by directed steep rock ridge. At the end of the 1970s suffuse pale spots. The dark spots of fringe are and the beginning of the 1980s, the population of weak, whereas in the nominate form they are dis the moth appeared to be very small, but from 1985 tinct and contrasting. In ssp. relicta, the hindwing is onward the population has increased, and e.g. in the pale silky green, often with unclear grey postmedial summers of 1992 and 1993 the species was abun line, while in the nominate form the hindwing is dant. The moth was legally protected in 1989. darker grey with two or three indistinct transverse During recent decades Ch. v-ata has been ex lines. The new taxon resembles ssp. lucinda Butler panding in North Europe. It was found for the first from Japan and the Far East but the latter is more time north of Berlin in 1954 in Zehdenick (Urbahn brightly green. 1964). The species was recorded in Denmark for Description. Wingspan: cJ average 13.7 mm the first time in 1973 (Torp 1974). It rapidly estab (range 12.5-14.5, N = 22), Q 15.5 (14.0-17.0, lished itself there and occurred abundantly in the N = 13) (nominate subspecies: cJ 16.1, 16.0-16.5, 1980s (Fibiger & Svendsen 1981). The first Swed N = 3; Q 17.6, 17.5-18.5, N =4). Ground colour of ish specimen was found in 1976 in Scania (Elmqvist forewing pale greyish green with silky sheen. Dark 1978), and the species was reported from several pattern fine and not strongly contrasting against provinces in southern Sweden in the 1980s (Palm ground colour. Antemedian line narrow but dis qvist 1985, 1986, 1987). In southern Norway the tinct. Costal part of postmedial line blackish grey, species was recorded in 1947 and 1955. Expansion forming sharp angle outward on vein R, weaker is also taking place in the Baltic countries; the toward dorsum. Subterminal line absent or very species was recorded in Lithuania in 1962 and in indistinctly marked by suffuse white spots. Fringe Latvia in 1963 (Sulcs & Viidalepp 1972, Fibiger & with weak dark spots. Hind wing pale silky green, Svendsen 1981, Mikkola et al. 1989). The expan often with unclear grey postmedial line. sion has reached Finland, too: the first specimen Material studied: Holotype: 0, Finland 668:32 Ab: outside Karkali was found on 21.-22.7.1985 at N: Karislojo 11.7. 1952 H. Krogerus leg. Deposited in Zoo Sibbo, Spjutsund (M. Landtman leg.). logical Museum, University of Helsinki (Helsingfors), Fin land. Para types: 2100 18QQ, all specimens being from the type locality, labelled Finland (or Fennia) Ab: Karislojo H. Krogerus leg. (deposited in Zoological Museum, Univer 3. Taxonomy sity of Helsinki (Helsingfors): 800 9QQ; in Coli. H. Krogerus, Helsingfors, Finland: llcJ0 9QQ; in Coli. M. The specimens collected at Karkali Peninsula differ Fibiger, Sora, Denmark: 10; in Coli. M. Landtman, externally in several respects from the expanding Helsingfors, Finland: 10). Central European taxon, including the specimen Biology. Several adult specimens have been from Sibbo, but no differences in the genitalia have collected during the daytime, flushed from their been found. In addition, the flight periods as well as day-resting sites on oak and lime tree trunks. A few the habitats appear to differ between the populations. specimens were found flying actively late after mid The population of Ch. v-ata of Karkali is hereby night. No specimens have been collected with light. described as The flight period appears to be from the last week of June to the first week of July, the earliest and Chlorocystis v-ata relicta ssp. n. latest collecting dates being 21.6.1993 and 17.7.1952. Etymology. From the supposed relict nature of The species has been reared ex ovo several the occurrence (see below). times. In the first experiment (Krogerus 1962), the ENTOMOL. FENNICA Vol. 7:99. 20.1X.1996 Errata Vol. 7, No 1, 1996, p. 36 In "Larval niche differences between the sibling species, Drosophila montana and D. littoralis (Diptera) in northern Finland" by Jouni Aspi (Entomologica Fennica 7: 36) the figure 5 was incorrect. The correct figure is reproduced below. 14,------------------------------, • "0 12 Ql ~ • Ql \0 E Ql ~ 8 g~ '""" 6- • ..91 • :.c: g. 4· .. .. eC/) • • . • .....• • Cl 2 ci z • • 0 0 5 10 15 20 25 30 No. Drosophila montana emerged Fig. 5. Association between the numbers of flies emerging from the yellow water lily substrate vials in Drosophila montana and D. littoralis. ENTOMOL. FENNICA Vol. 7 • Krogerus: Chloroclystis v-ata relicta ssp. n. 65 2 Fig. 1-4. -1: Ch/oroclystis v-ata relicta ssp.n., holotype d', Finland, Karkali. - 2: Ch/oroclystis v-ata relicta ssp.n., paratype Q, Finland, Karkali.-3: Chloroc/ystis v-ata v-ata (Haworth). d', Denmark, Mellemskov.-4: Ch/oroc/ystis v-ata v-ata (Haworth). Q, Denmark, Gedesby. larvae were fed with leaves and flowers oflime, as pupates at the beginning of August and the pupa the females were found resting on trunks of that hibernates in the litter. tree; the larvae appeared to be cannibalistic. In later experiments the leaves of all plant species growing in the habitat of Ch. v-ata were offered to the 4. Discussion larvae, as well as some plant species mentioned in the literature as food plants of the species. The The new subspecies seems to be strictly larvae clearly preferred the leaves of Eupatorium univoltine, flying in late June and early July. In cannabinum (Asteraceae) , which does not occur in central Europe the species is bivoltine, the flight the region. The most probable host plant in Karkali period of the generations being from the begin appears to beMercurialis perennis (Euphorbiaceae). ning of May to the end of June, and from the end Both the ground colour and pattern of the larva of July to August (Fibiger & Svendsen 1981). of Ch. v-ata are variable ( cf. Juul1948). The young Skou (1984) mentions mid-May to mid-June and larva of ssp. relicta is yellowish white with three mid-July to late August. The offspring of the black longitudinal lines, the dorsal line straight, summer brood pupates in the autumn and the lateral lines undulate. In the fully grown larva, the pupa hibernates. ground colour is dorsally pale brown, laterally yel The isolated population inhabiting Karkali is lowish brown, with bright yellow intersegmental most probably a relict one from the warm Litorina rings. Every segment, except the first one, contains period 7 000 years ago. Several other isolated a brown triangular spot. The ground colour of some plant and animal populations that are considered larvae is greenish up to the last ins tar. The length of to be relics, e.g. the plant species Hypericum the larval period is around three weeks. The larva montanum and Cirriphylum tenuinerve, the gas- 66 Krogerus: Chloroclystis v-ata relicta ssp. n. • ENTOMOL. FENNICA Vol. 7 tropod Cochlodina orthostoma, the beetles References Leiopus punctulatus and Pseudanostirus glo Elmqvist, H. 1978: Det svenska fyndet av Chloclystis v-ata Hw. bicollis and a moth, Aplota kadeniella (Herrich (Lep., Geometridae).-Entomol. Tidskr. 99:109-110. Schaeffer), are known around Karkali and Lake Fibiger, M. & Svendsen, P. 1981: Danske natsommerfugle. Lojo (Lohjanjarvi). Aendringer i den danske natsommerfuglefauna i The fate of this interesting taxon is alarming. perioden 1966--1980.-Dansk Faunistisk Bibliotek. Bind 1. Klampenborg. The single specimen of the nominate subspecies of Juu1, K. 1948: Nordens Eupithecier.-Aarhus, 145 pp. Ch. v-ata from Finland may have been a wind Krogerus, H. 1962; bverraskande beteende hos larven av blown individual but, if the taxon invades the coun Dyserga coronata. - Notulae Entomol. 42:97. try, which seems unavoidable, there are no means Mikkola, K., Ja1as, I. & Peltonen, 0. 1989: Suomen perhoset. Mittarit 2. -Hanko, 280 pp. to prevent it from crossing with ssp. relicta. We can Palmqvist, G. 1985: Intressanta fynd av Macrolepidoptera see only two ways in which the taxa would not i Sverige 1984.-Entomol. Tidskr. 106:65-70. hybridize: ( 1) the different phenology would keep 1986: Intressanta fynd av Macrolepidoptera i Sverige them as parapatric populations or (2) they would 1985.-Entomol. Tidskr.l07:65-69. 1987: lntressanta fynd av Macrolepidoptera i Sverige have differentiated at species level and would be 1986.-Entomol. Tidskr. 108:135-139. genetically imcompatible. Both alternatives seem Skou, P. 1986: Nordens malere. Danmarks Dyreliv 2. improbable. Kobenhavn & Svendborg. Sulcs, A. & Viida1epp, J. 1972: Verbreitung der Gros schmetterlinge im Baltikum.-Deutsche Entomol. Z. N.F.l9:151-209. Acknowledgements. Michael Fibiger is acknowledged Torp, R. 1974: Ny dansk maier Chloroclystis v-ata Hw. for placing Danish material at my disposal. I also thank Lepidoptera, Bd. 2, pp. 203-206. Lauri Kaila who took the photographs and translated my Urbahn, E. 1964: Verzeichnis von Schmetterlingarten die manuscript into English, and Kauri Mikkola who made zunachst besonders zu beachten und zur Kartierung zu valuable comments on the manuscript. melden sind.-Entomol. Ber., Berlin 1964:41-45.