Insectes Sociaux, Paris Masson, Paris, 1983 1983, Volume 30, n ~ 2, pp. 14%164 ANT CHROMOSOMES II, KARYOTYPES OF WESTERN PALEARCTIC SPECIES * E. HAUSCHTECK-JUNGEN (1) and H. JUNGEN (2)** tl) Zootogisches Institut der UniversiRit Ziirich, Winterthurerstr. 190, CH - 8057 Ziirich, Switzerland (2) Zoologisches Museum der Universitlit Zi'trich, Winterthurerstr, 190, CH - 8057 Zi~rich, Switzerland Regu le 6 d6eembre 1980. Accept6 le 23 avril 1982. S UMMARY The chromosome numbers of 40 ant species are reported. For 22 species the karyo- types as ~r as the chromosome numbers are presented. The chromosome numbers range between n = 8 and n = 26. Remarkable karyotypes are those of the germs LaMas in exhibiting mainly acrocentric chromosomes. In all other ?~aryotypes the majori:ty of chromosomes show medio- or submediocentric centromere position. Differences in chromosome numbers in the genus Camponotus reflect the grouping in subgenera 'with the exception of Taneemyrmex. This pattern is not true for the genera Aphaenoeaster and Leptothorax, where a variety of chromosome numbers ~r found in the different subgenera. ZUSAMMENFASSUNG Ameisenchromosomen:- IL Karyotypen westpal~arktischer Arten Die Chromosomenzahlen yon 40 Ameisenarten ,~verden mitgeieilt. Ffir 22 Arten wird zus~tztich der Karyotyp vorgelegt. Die haploiden Chrornosomenzahlen bewegen sich zwischen n = 8 und n = 26. Bemerkenswert sind die Karyotypen der Gatttmg Lasius. Diese Karyotypen besitzen, abgesehen yon einern oder zwei mediozentrischen Paaren. ausscbliesslich acrozentrische Chromosornen. ARe fibrigen Karyotypen bestehen iiber- wiegend aus rnedio- bzvr submediozentrischen Chrornosornen. In der Gattung Carnponorus emspricht die Gruppierung in Untergattungen auch einer Gruppierung yon unterschiedlichen Chrornosomenzahlen. Fi.ir die Gattungen Aphceno. gaster und Leptothorax gilt diese Entsprechung nicht. (*) Supported by: Karl HESCHELER-STIFrur~G, Georg und Antoine CLARAz-ScFIENKUNG, and by grants of the Schweizerischer Nationalfonds zur F,Srderung wissenschaftticher Forschnng Nr. 4326, 4847, 3.187.69, (**) The former students Peter DUELLI. Hans HOSBACH, and Othmar KUHN took part in the chromosome studies, 150 E. HAUSCHTECK-JUNGEN and H. ]UNGEN INTRODUCTION The origin of the Formicid~ is in the Mesozoic era (WILSON et al., 1967), so the morphological and behavioural characteristics as well as the chromo- some sets could develop over a long time span. In fact, the haploid chro- mosome numbers of Formicid~e cover the range between 4 (HAuSCHTECK, 1962 ; IMAI and KuBora, 1972) and 42 (IMAI et al., 1977), eventually even more than 45 (TAYLOR, 1978). The chromosome diversification arose independently in different subfamilies. Mechanisms of karyotype evolution, such as centric fission and fusion, chromosome polymorphism, B chromosomes, translo- cations, pericentric and paracentric inversions and DNA amplification have been discussed by Cg0zIER (1975) and L~I et al. (1977). Besides insights into general mechanisms of karyotype evolution, which are summarized for instance by JOHN and LEwis (1968) or WHITE (1973), the karyotype analysis should clarify taxonomy. The karyotypical variability in some genera, e.g. Camponotus or Aphcenogaster, can be quite large. Of course, morphological or ecological variability of a taxon does not have to be paralleled by karyological variability. CROZIER (1975) summarized all chromosomal data on ants up to 1975. Since then, additional results were presented on the genus Formica (HAuscHTECK-JUNCEN and JvNcz~q, 1976) on Australian species (IMAI eL at.. 1977). In spite of a relatively large number of species investigated up to now, cytotaxonomie information on the western patearctic ant species is still fragmentary. With two exceptions, this paper presents karyotypes of European and North African species of Formicidze. Most of the chromosome numbers are already previously mentioned in CROZIER (1975). MATERIAL AND METHOD As in other insects, the suitable material to find mitosis are the cerebral ganglia of preputree. Dissected ganglia from atl castes available ~vere kept in" sterile ringer solution to which Colcemid ~vas added to a final concentration of 0,004 %. After one to three hours incubation the organs were transferred to a t g's sodium citrate solution for 20 to 40 re.in. They ~vere then fixed in 50 % acetic acid and stained in acetic orcein, The cells ~vere squashed under a siliconized coverslip, ~vhich was removed after being frozen on dry ice. Permanent preparations ~vere made by mounting in Euparal. For determination of the chromosome number ten mitoses with the same mammal chromo- some number were thought to be enough to determine the diploid or haploid chromo- some number of the species. RESULTS AND DISCUSSION Bothriomyrmex : The karyotype of B. gibbus (not figured, table D is characterized by one long subtelocentric chromosome, twice as long as the ANT CHROMOSOMES 151 next one, which is submediocentfic. Pair three is mediocentric, pairs five and six are submediocentric. The smaller chromosomes are acrocentric. Tapinoma ([ig: I a, I b, table I): The karyotype of T. erraticum looks similar to one of the karyotypes known from the American T. sessile. CROZIER (1970 b) describes for this species a chromosomal potymorphism, the karyotypes differing by pericentric inversions. One of the karyotypes Fig. 1. -- Karyotypes and metaphase plate. 2 000 • a) Tapinoma erraticum, diploid set, 2 n = 16. b) T. nigerrimum, haploid metaphase, n -- 9. c) Plagiotepis pygmaea, diploid set. 2 n --- 18. d) P. barbara, haploid set, n = 9. e) Lasius (Lasius) atienus, diploid set, 2 n = 30. f) L. (Cautolasius) flavus, diploid set, 2 n = 30. g) L. (DendroIasius) fuliginosus, haploid set, n --- 14. Abb. 1. -- Karyotypen und Metaphaseptatten. 2 000 x. a) Tapinoma erraticum, diplolder Satz, 2 n = 16. b) T. nigerrimum, haptoide Metaphase, n = 9. c) Plagiolepis pygmaea, diploider Satz. n = 18. d) P. barbara, haploider Satz, n = 9. e) Lasius (Lasius) alienus, diploider Satz. 2 rt = 30. f) L. (Cautolasius) flavz~s, diploider Satz, 2 n = 30. g) L. (Dendrotasius) fuIiginosus, haploider Satz, n = 14. 152 E. HAUSCHTECK.JUNGEN and H. JUNGEN Table I. -- Haploid chromosome numbers of European and North African ant species. Metaphases from queens and workers ~ere diploid, those from males haploid. At least one nest from each collection site 'was analysed. Nests ~ith c~romosomal aberrations are omitted here. CH: S'witzerland, D: Federal Republic of Germany, E: Spain, F: France, GR: Greece, I: Italy, TN: Tunisia, USA: United States of America, YU: Yugoslavia. n: haploid chromosome number. Tabelle I. -- Haptoide Chromosomenzahlen europ4iischer und nordafrikanischer Ameisen- arten. Metaphasen yon K.~Sniginnen und Arbeiterirmen ,waren diploid, solche yon Mfirmchen haploid. Von jedem Ftmdort wurde mindestens ein Nest untersucht. Nester, in denen Tiere mit chromosomaler Aberration gefunden ~urden, sind bier nicht aufge~hrt. CH: Sch~ceiz, D: Bundesrepublik Deutschland, E: Spanien, F: Frankreich. GR: Griechenland, I: Italien. TN: Tunesien, USA: Vereinig~e Staaten yon Amerika, YU : Jugosla~viem. n: haploide ChromosomenzahL Species Collection site n Caste Number analysed of nuclei analysed Dolichoderin~e Tapinomini Bothriorn yrmex gibbus Genova (I) 11 ~ > 10 Tapinoma erraticum Pfin',vald (CH) 8 ~ g ~ > 10 Dietsdorf (CFI) Boppelsen (CH) Pr~les (CH) Locarno (CH) T. nigerrimum Tunis (TN) 9 4 > 10 Tabarka (TN) T, simrothi Tunis (TN) 9 9 ~ > 10 Jefna (TN) Malaga (E) Formicin~e Plagiolepidini Plagiolepis barbara Tunis (TN) 9 ~ 6 > 10 P. pygmaea Torremolinos (E) 9 9 ~ c~ > t0 Malaga (E) Loja (E) Tessin (CH) Wallis (CH) Podgara (YU) Formicini Lasius ( Cautolasius ) flavus Ziirich (CH) 15 9 ~ > 10 L. (Dendrolasius) fuliginOsus Ziirich (CH) 14 ~ > 10 Pavia (I) L. ( Lasius ) alienus Kaiserstuhl (D) 15 r g > 10 Sur En (CH) Celoni Gerona (E) Fiirstenau (CH) Camponotini Camponotus (Camponotus) ligniperda Wallis (CH) 14 9~ > I0 Camponotus (Myrmosericus) cruentatus Diezma (E) 18 7 ANT CHROMOSOMES 153 Species Collection site Caste Number analysed of nuclei analysed C. (M.) rufoglaucus Sedjenane (TN) I8 ~ 8 > I0 Tabarka (TN) Granada (E) Camponotus (Tana~myrmex) azthiops St-Giles (F) 21 9~ > 10 Yugoslavia C. (T.) alii Alcoy (E) 21 6 C. (T.) compressus Tabarka (TN) 20 ~ > 10 Tunis (TN) C. (T.) foreli Malaga (E) > 10 C. (T.) pilieornis Ordal (E) 25 6 C, (T.) sytyaticus Rhodos (GR) 20 ~6 > 10 Hospitalet (E) Ordal (E) CataglypI~is albicans Hospitalet (TN) 26 > 10 C. bicolor Israel 2698 > 10 Tabarka (TN) Ponerin~ Ponerini Ponera pennsylvanica USA > 10 Myrmicinze Myrmieini (broad sense) Aphcenogaster ( Aphcenogas ter ) depitis Tunis (TN) 17 2 Sedjenane (TN) A. (AJ sardoa Sedjenane (TN) 17 2 A. (A.) testaceopilosa Malaga (E) 17 ~$ > 10 Tunis (TN) Sibenik (YU) Aph~enogaster (Attomyrma) subterranea Pfirrwatd (CH) 11 ~. > 10 TesSin (CH) Pr~les (CH) Kaiserstuhl (D) Harpagoxenus subl~vis Niirenberg (CH) 20 ~8 > 10 Leptothorax (Leptothorax) acervorum Bonn (D) 13 g8 > I0 Sur En (CH) Wallis (CH) MaILx (CH) Leptothorax (Myralant) interruptus Wiirzburg (D) 12 > I0 L, (M,) nylanderl Boppelsen (CH) 3 L. (M.) schaumi Ithaka (USA) 9 2 L, (M.) tuberum Graub~ndcn (CH) 9 9~6 > 10 Waltis (CH) Braurtwatd (CH) Sur En (CH) 154 E. HAUSCHTECK.JUNGEN and H. JUNGEN Species Collection site n Caste Number analysed of nuclei analysed L. (M,) unffasciatus Bonn (D) 9 ~ > I0 Pr~les (CH) Dielsdorf (CH) Graubfinden (CH) Manica rubida Biirglen (CH) 22 ~ > 10 Myrmica &evinodis Greifensee (CH) 24 9 ~ > 10 Ziirich (CH) M. ruginodis Fiirstenau (CH) 24~