** STEPHEN P. SCHEMBRI * and CEDRIC A. COLLINGWOOD A REVISION OF THE MYRMECOFAUNA OF THE MALTESE ISLANDS (HYMENOPTERA, FORMICIDAE) INTRODUCTION In 1924, Emery published a short paper in which he listed seven species of ants identified by him from a small collection made by Sil- vestri on Malta (EMERY, 1924). No further work was carried out until 1968 when Baroni Urbani published a comprehensive work on the ant fauna of the Maltese group in which he added another 23 species, bring- ing the total number to 30 (BARONI URBANI, 1968a). In a further paper, BARONI URBANI (1968b) discussed the biogeography of the Maltese myrmecofauna. Collections made over the period 1975-1979 by one of us (SPS) have included 29 out of the 30 species previously recorded, and have added a further 14 to the Maltese list, bringing the total to 44 species. The present work discusses these new findings and extends the distri- bution records of BARONI URBANI (1968a). Many of the Maltese po- pulations show interesting and sometimes puzzling morphological va- riations when compared to populations of the same species from the European mainland, and these are also discussed. SPECIES LIST The name of the species is given first followed by previous re- cords from the Maltese Islands. Full data are included for the less common species. Notes on taxonomy and ecology are included where relevant. Species marked with an asterisk have not previously been recorded from the area. * 72 Brared Street, Birkirkara, Malta. ** Ministry of Agriculture, Lawnswood, Leeds, England. S.P. SCHEMBRI - C.A. COLLINGWOOD - stations searched for ants. o z o : Fig. 1 Map of the Maltese Islands showing G Ta' Fort Cham- 1, Dwejra; 2, Wied Sara; 3, Rabat; 4, Wied tal-Lunzjata; 5, Cenc; 6, Wied bray; 7, Mgarr; 8, Iz-Zewwieqa; 9, San Bias; 10, Calypso Cave; 11, 1-Infern, : Santa Qbajjar, Qolla s-Safra; C o m i n o 12, San Niklaw Bay; 13, Marija Bay; Paradise 14, Village, Tower, Central area; Cominotto, 15; Malta: 16, Wied Bay; 17, Ramla tat-Torri; 18, Slugs Bay; 19, Ghadira; 20, Ghajn Tuffieha; 21, Chadwick Gnejna; 22, Wied il-Hmar; 23, Gnejna; 24, Bahrija; 25, Fiddien; 26, Lakes; 27, Rabat; 28, Buskett; 29, Wied il-Hesri; 30, Wied Qirda; 31, Ghar Lapsi; 32, Hagar Ghar Qim; 33, Wied Babu; 34, Il-Maqluba; 35, Kirkop; 36, Wied Has-Sabtan; 37, St. 40, Il-Ballut ; Hasan; 38, Fort Lucian (Marsaxlokk) ; 39, Marsaxlokk; (Marsaxlokk) 41, St. Thomas Bay; 42, Marsascala; 43, Wied Ghammieq; 44, Kalkara; 45, Valletta; 51, At- 46, Marsa; 47, Wied is-Sewda; 48, Fleur-de-Lys ; 49, Birkirkara; 50, Balzan; Wied tard; 52, Wied Incita; 53, Ta'Qali; 54, Wied Ta'1-Isperanza; 55, L-Iklin; 56, il-Ghasel; 57, Bidnija; 58, Ghajn Rihana; 59, Wied Qannotta; 60, Wardija; 61, Mistra; Tal-Blata 63, Salina; 64, Bahar ic-Caghaq; 65, Wied il-Faham; 66, St. 62, (Selmun); Paul's Wied il-Kbir ; Gzira ; 69, Sliema ;St. Is., George's Bay ; 67, (Spinola) 68, 70; Filfla, 71. PONERINAE 1. Hypoponera eduardi (Forel, 1894) Hypoponera eduardi For., BARONI URBANI, 1968a: 416 Hypoponera eduardi (Forel), BARONI URBANI, 1971 : 15 Malta: Fort St. Lucian (Marsaxlokk) 26.VIII.75 ??, 26.VII.76 Birkirkara $$, 9.VIII.76 $?; Wied il-Ghasel 17.IX.75 $ (ergatoid); MYRMECOFAUNA OF THE MALTESE ISLANDS VII.76 ??, VIII.76 ??; Chadwick Lakes VI.77 $& VIII.77 $$; Wied Qirda 6.VII.77 ^; Ghajn Rihana IX.77 $$; Wied Qannotta 25.111.78 ^. This is an uncommon but widespread species. A series of workers from a single colony was first taken by Baroni Urbani at Buskett. The only colony discovered during the present collections was situated in humid soil beneath thick plant cover. Workers, either singly or in small groups, were found under stones and in leaf litter but did not appear to be associated with a colony. A single ergatoid male was taken from soil under a stone; no attendant workers were present. Alate females were taken variously during the months of July and August. H. eduardi has a discontinuous distribution from North. West Spain, South Europe, North Africa to the Middle East. Its biology has been studied by LE MASNE (1956), who found that colonies of morphologically identical workers and queens may produce either ergatoid or normally winged males. 2. *Proceratium melinum (Roger, 1860); (Fig. 2) Two males were collected separately, one flying at dusk at Bir- kirkara and the other from under a stone at Chadwick Lakes, both during September 1976. The specimens are only tentatively identified as P. melinum as the males of this genus are little known. - Fig. 2 Proceratium melinum (Roger): male from Chadwick Lakes, Malta; lateral aspect; scale bar, 1 mm. 420 S.P. SCHEMBRI - C.A. COLLINGWOOD 3. *Amblyopone denticulatum (Roger, 1859) from leaf litter in shade at Wied il- A single worker was taken distributed Ghasel on 29.111.78. This species is widely but sparsely Balkans and the Middle East. from Spain through South Europe to the DOLICHODERINAE 4. Iridomyrmex humilis (Mayr, 1868) 1971 : 166 Iridomyrmex humilis (Mayr), BARONI URBANI, 1968a: 474; Malta: Ghajn Rihana ^; Chadwick Lakes ^; Mistra ?$ ^; il-Ghasel Bir- Buskett $? 99; Balzan ?? ^; Salina ^; Wied ?? ^; kirkara 33; Ghar Hasan area ^. C o m i n o : Santa Marija Bay $$. G o z o : Dwejra $$; Wied tal-Lunzjata $$. in various habitats with a This is a widespread species, occurring and is abundant where it is found. marked preference for shade usually on Malta and Gozo BARONI URBANI (1968a) found it in several localities at Santa where it continues to flourish and it was also taken on Comino Marija Bay. Its distribution seems to be extending. Tapinoma the of the re- Tapinoma erraticum (Latr.) was only species genus found on all corded by BARONI URBANI (1968a) which he plentifully three Maltese Islands visited. However, in the present study two of ventral T. erraticum (Latr.) Fig. 3 - Genitalia of male Tapinoma spp.; aspect; A, T. from Devon, England; B, T. simrothi Krausse from Comino, Malta; C, nigerrimum (Nyl.) from Birkirkara, Malta; scale bar, 1 mm. MYRMECOFAUNA OF THE MALTESE ISLANDS the other common South European/North African species have been recognised. The species can be distinguished in the male and queen castes as follows : Males 1. Stipes long, narrow and sharply curved inwards towards their tips (Fig. 3B); third funicular segment x2.5 as long as broad simrothi Krausse broad not curved 3 third funicular Stipes sharply (Figs. A & C) ; segment x2 as long as broad or less 2 2. Stipes voluminous; lateral lobes of subgenital plate narrower than enclosed space (Fig. 3C); scape shorter than head width behind head width 1 . 1 eyes ; mm nigerrimum (Nylander) Stipes not conspicuously enlarged; lateral lobes of subgenital plate wider than enclosed space (Fig. 3A); scape longer than maximum head width behind head width less than 1 eyes ; mm erraticum (Latreille) Females 1 . Clypeal incision shallow, not deeper than wide (Fig. 4A) .... erraticutn (Latreille) " Clypeal incision deeper than wide (Fig. 4B) 2. Head width 1.3-1.5 mm; pubescence thick overlapping scape margin as a subdecumbent fringe .... nigerrimum (Nylander) Head width 1.1-1.25 mm; scape pubescence thin and decumbent simrothi Krausse 5. Tapinoma erraticutn (Latreille, 1798) Tapinoma erraticum (Latr.), BARONI URBANI, 1968a: 475; 1971: 159 The only species of the genus Tapinoma recorded by BARONI URBANI (1968a) from various localities on Malta, Gozo and Comino. 6. Tapinoma simrothi Krausse, 1909 Malta: Wied il-Kbir; Wied il-Ghasel; Buskett; Wardija; Wied Qannotta, all <$<$, taken singly or away from nests. : San Niklaw near near all Comino Bay ; Village ; Tower, <&?, S.P. SCHEMBRI - C.A. COLLINGWOOD - T. Fig. 4 Heads of Tapinoma workers; frontal aspect; A, erraticum (Latr .) from Dorset, England; B, T. simrothi Krausse from Comino, Malta; scale bar, 1 mm. and was taken singly or away from nests. A colony containing $$ <? 5 discovered in the central part of the island. The males have the characteristic genital configuration of T. simrothi with long strongly inward curving stipes and narrow subgenital Central and North plate lobes and are quite unlike those of European populations of T. erraticum which have short stipes and broad subgenital have the narrow plate lobes (Fig. 3B). Most of the females and workers clypeal incision characteristic of T. simrothi. The T. simrothi colonies contained abundant workers nesting in soil and under stones mainly in garigue communities. In places where MYRMECOFAUNA OF THE MALTESE ISLANDS human interference is minimal, the nest is extended above the ground as a fragile earth dome with numerous chambers and supported by woody shrubs. Males identified as T. simrothi were taken in March and April. 7. *Tapinoma nigerrimum (Nylander, 1856) Two typical males of this species were taken near human habita- tions on 19.V.78 at Birkirkara (Malta). Males of T. nigerrimum are much than larger those of T. erraticum and are easily distinguished by the ge- nitalia which have broad and weakly curving stipes (Fig. 3A & C). MYRMICINAE ^Stenamma petiolatum Emery, 1897 A single worker of this species was taken foraging above ground at Wied il-Ghasel (Malta) on 19.V.78. This is a rare species, so far only recorded from Italy. A single record from San Nazarro in Switzerland also exists (KUTTER, 1978). 9. Aphaenogaster splendida (Roger, 1859) Aphaenogaster splendida (Rog.), BARONI URBANI, 1968a: 418; 1971 : 54 Malta : Chadwick Lakes ?; Kalkara ??d$^; Buskett ??c?c? ; Gzira Rabat Fiddien Marsaxlokk Birkirkara ?; $; ; $^; $c?55; Mistra Bahrija ; ? $5. C o m i n o : Santa near Marija Bay ? ; Village $$. This species occurs in a variety of habitats, occassionally also close to human habitations. It is a shade-loving species nesting in soil under deeply embedded stones, flower pots and in crevices.