Morphological comparison of them a l e genitalia of Formica fuscagroup (Hymenoptera: Formicidae) inK o r e a Min-Soo D o n g 1, S a m - K y u K i m * 1,* Department o f Applied Biology, K a n g w o n National University, Chuncheon 24341, Korea Abstract Taxonomic significance ofm a l e genitalia havew e l l known inm a n y insects but largely ignored inanttaxonomy due tocollecting difficulties ofmale. Nevertheless, recent studies showed thatgenitalic structure ofm a l e ant canbeagood diagnostic character inspecies level, noattempt has beenm a d e onKorean antusing m a l e genitalia. W e were abletom a k e m a n y collections accompanying w i t h males, rendering ittoexamine m a l e genitalia in detail f o r thef i r s t time inKorea. A s thebeginning ofthestudy ofm a l e genitalia ofKorean ants,w e provide morphological comparison between F o r m i c a fuscaLinnaeus, 1758, F. hayashi Terayama & Hashimoto, 1996 and F. japonicaMotschoulsky, 1866, ingenitalic structure. Significance ofm a l e genitalia inKorean anttaxonomy isdiscussed. Photographs anddescription of m a l e antsare provided inthis study. K e y words: A n t , Formicidae, Genitalia, Taxonomy, Morphology Introduction The antsbelonging toF o r m i c a fuscaspecies group areblack-colored antscommonly found throughout Europe asw e l l asparts ofSouthern A s i a andAfrica. I t isgenerally very difficult todistinguish themf r o m each other due totheir highdegree ofmorphological similarities. F o r thisreason, m a n y myrmecologists are struggling toidentify thematthespecies level. A s part ofthiseffort,recent attempts have been m a d e tousethem a l e genitalia f o r taxonomic purposes. Therefore, w e explored distinct characters f r o m m a l e genitalia ofF o r m i c a fuscagroup known f r o m Korea f o r thef i r s t time.W e provides detailed imagesofm a l e genitalia andcharacters f o r all species known f r o m Korea inthis study. Systematic accounts A B C Family Formicidae Latreille, 1809 S u b f a m i l y Formicinae Latreille, 1809 T r i b e Formicini Latreille, 1809 Extant genera included: Alloformica, Bajcaridris, Cataglyphis, F o r m i c a , Iberoformica, Polyergus, Proformica, Rossomyrmex Type-genus: F o r m i c a Linnaeus, 1758 G e n u s F o r m i c a Linnaeus, 1758 Type-species: F o r m i c a rufaLinnaeus, 1761 F o r m i c a f u s c a Linnaeus, 1758 D E F Diagnostic characters: Numerous setaeentirely covered mesoscutum (Fig.1A).Petiole inlateral v i e w relatively short (Fig.3A).A p e x ofbasimere slightly concave, not angulate (Fig.3B);telomere inlateral v i e w distinctly l o n g e r thanhigh, w i t h v e r y short setae; post-dorsal m a r g i n oftelomere curved abruptly; ventral m a r g i n oftelomere slightly concave (Fig.3B).Pygostyle digitiform entirely hairywith asingledistinctly long seta(Fig.3C).Digitus inlateral v i e w claw-shaped, apexpointed; basal projection ofcuspiswell-developed, elongated; post-dorsal m a r g i n ofvalviceps round. Posterior m a r g i n ofabdominal tergumIX straight inposterodorsal v i e w (Fig.4C). R e m a r k s : This species w a s previously known asF. lemani inK o r e a butw e treated thisspecies asa misidentication ofF o r m i c a fuscabythefollowing characteristics: 1.N o m o r e than6erect hairs (Radchenko, 2005) onthepronotum ofworker. 2.Workers with l e s s than3hairs inm i d f e m u r . G H I H o w e v e r , according toD l u s s k y andPisarski (1971), there are somevariable individuals without any setae on thepronotum, w h i c h requires closeexamination. This species iscommon inmountainous highlands ofm o r e than1000 meters. F o r m i c a hayashi Terayama & Hashimoto, 1996 Diagnostic characters: Sparse setae onmesoscutum posteriorly, absent anteriorly (Fig.1B).Petiole inlateral v i e w reverse V-shaped (Fig.3D).A p e x ofbasimere slightly concave (Fig.3E);telomere in lateral view distinctly longer thanhigh, w i t h very short setae; post-dorsal m a r g i n oftelomere curved gradually; ventral m a r g i n oftelomereslightly concave (Fig.3E).Pygostyledigitiform entirely hairy with asingle distinctly long seta(Fig.3F).Digitus inlateral v i e w claw-shaped, apex pointed; basal projection ofcuspis well-developed, sharp; post-dorsal m a r g i n ofvalviceps round. Posterior m a r g i n Figure 3 . Morphological comparison o f maleF o r m i c a fusca groupi n Korea (A-I); F. fusca(A,B,C).,F. hayashi ofabdominal tergumIX trapezoid-shaped inposterodorsal v i e w (Fig.4F). (D,E,F).,F. japonica (G,H,I). Lateral viewo f male, Lateral viewo f genitalcapsule a n d pygostyle, respectably. S c a l e bar: A,D,G =2 m m , B,E,H =1 m m Remarks: Worker of this species can be distinguished from the morphologically similar species, F. japonica by the following characteristics: 1. posterolateral corners of head rounded in frontal view, A Bm 2.antennal scape long . 3.Absence oferect hairs onthe2n d gastral tergites excepting arowofhairs B C Pygostyle V c ontheposterior m a r g i n (Terayama & Hashimoto, 1996). Thisspecies iscommon inmountainous Cs areas, especially inBaekdudaegan. T m F o r m i c a japonicaMotschoulsky, 1866 Diagnostic characters: Manysetae onmesoscutum posteriorly, absent anteriorly (Fig.1C).Petiole inlateral v i e w reverseV-shaped, apexblunt (Fig.3G).A p e x ofbasimere distinctly concave (Fig. Dg 3H);telomere inlateral v i e w distinctly longer thanhigh, w i t h v e r y short setae; post-dorsal m a r g i n of Cs telomere curved gradually ;ventral m a r g i n oftelomereslightly concave, almoststraight (Fig.1H). 200µm Lp Pygostyle digitiform entirely hairy with acouple oflong setae(Fig.3I).Digitus inlateral v i e w claw-shaped, apex pointed; basal projection ofcuspis relatively g e n t l y projected, not acute; post- dorsal m a r g i n ofvalviceps round. Posterior m a r g i n ofabdominal tergumIX convex inposterodorsal v i e w (Fig.4I). D E F R e m a r k s : This species isthem o s t commonspecies inthis group. Easy toseeeven inthecityarea. A B C G H I Figure 1 . Mesoscutum o f maleF o r m i c a fusca groupi n Korea (A-C); F. fusca (A).,F. hayashi (B).,F. japonica (C).S c a l e b a r : A,B,C =1 m m A B C 200µm 200µm Figure 4 . Dissected genitalia o f F o r m i c a fusca groupinKorea(A-I); F. fusca (A,B,C).,F. hayashi (D,E,F)., F. japonica (G,H,I).Paramere a n d volsella, penisvalva a n d abdominal tergumIXw i t h pygostyle, Figure 2 . Workers o f F o r m i c a fuscagroupi n Korea (A-C); F. fusca (A)., F. hayashi (B).,F. respectively. B m basimere, C s cuspis, D g d i g i t u s , L p lateral apodeme o f penisvalva V c valviceps japonica (C)..