Aleocharine rove beetles (Coleoptera, Staphylinidae) associated with Leptogenys Roger, 1861 (Hymenoptera, Formicidae) I. Review of three genera associated with L. distinguenda (Emery, 1887) and L. mutabilis (Smith, 1861)

Abstract Three myrmecophilous genera of Aleocharinae (Staphylinidae) associated with Leptogenys distinguenda (Emery, 1887) and Leptogenys mutabilis (Smith, 1861) are reviewed with descriptions of new taxa: Maschwitzia Kistner, 1989, Togpelenys Kistner, 1989 and Witteia Maruyama & von Beeren, gen. n. (type species: Witteia dentilabrumMaruyama & von Beeren, sp. n.). The following new combinations are proposed: Zyras (s. lat.) aenictophila (Kistner, 1997),comb. n. (ex Maschwitzia), Zyras (s. lat.) dichthadiaphila (Kistner in Kistner et al., 2003), comb. n. (ex Maschwitzia), Maschwitzia derougemonti (Pace, 1984), comb. n. (ex Wroughtonilla Wasmann, 1899), Maschwitzia watanabei (Maruyama, 2004), comb. n. (ex Wroughtonilla), Maschwitzia dilatata (Pace, 2005), comb. n. (ex Wroughtonilla), Witteia borneensis (Pace, 1986), comb. n. (ex Wroughtonilla). These genera belong to the Wroughtonilla genus group of the tribe Lomechusini.


tonilla genus
group of the tribe Lomechusini.

Introduction

Th e ant genus Leptogenys Roger, 1861 belongs to the subfamily Ponerinae.Some of its members show army ant-like behavior (Maschwitz et al. 1989, Kronauer 2009).Many Leptogenys species harbor various groups of myrmecophilous insects comparable to the myrmecophile richness of the classic army ants of the subfamilies Dorylinae, Aenictinae and Ecitoninae (Witte et al. 2008).Rove beetles associated with Leptogenys ants have been studied by several authors based on the material collected by ant researchers (Wasmann 1899;Kistner 1975Kistner , 1989;;Kistner et al. 2008;Hlaváč and Janda 2009).Th e rove beetles associated with Leptogenys ants show strict host-species specifi city, i.e. one rove beetle species is associated with only one host ant species (Maruyama, unpublished data; von Beeren and Witte, personal observations).In this article we present the fi rst known exception to this rule, with Maschwitzia ulrichi Kistner, 1989 occurring in two closely related Leptogenys host species.Th e already described species, M. ulrichi and Togpelenys gigantea Kistner 1989 were recorded from colonies of Leptogenys distinguenda (Emery, 1887) at Ulu Gombak in Peninsular Malaysia (Kistner 1989).Although the former species was recorded from a L. borneensis colony (Kistner et al. 2008), this is most probably based on a misidentifi cation (Maruyama et al. 2010).Recently, the junior author (CvB) collected a series of rove beetles from L. distinguenda colonies and from one L. mutabilis (Smith, 1861) colony in Peninsular Malaysia.Th e material included an unknown species with an autapomorphy, which did not allow it to be assigned to any known genus.

In the present article, we revise some of the rove beetle genera associated with Leptogenys ants.Th is fi rst part of the series reviews the genera which are associated with L. distinguenda and L. mutabilis, including

escriptions of some ne
taxa and some new combinations.


Materials and methods

Th e rove beetles were collected in spring and autumn 2008 and 2009 in a well regenerated dipterocarp rainforest in the Field Studies Centre of the University of Malaya in Ulu Gombak, Malaysia (03° 19.4796' N, 101° 45.1630' E, altitude 230 m) and near the Institute of Biodiversity in Bukit Rengit, Malaysia (03°35.779N, 102°10.814'E, altitude 72 m).Nests of the nocturnal host ants were located during the night by backtracking Leptogenys raiding trails.Since all rove beetles follow the host ant migrations, we detected them on these occasions and collected them with aspirators (for further information see Witte et al. 2008).Th e specimens were put in 1.5 ml plastic tub containing 80 % ethanol for morphological studies.

Th e methods of dissecting and line drawings followed Maruyama (2006).Dissected genitalia and mouthparts were mounted in Euparal on a small glass plate (10 × 5 mm), and subsequently glued onto a paper card (6 × 5 mm) and pinned under the respective specimen (Maruyama 2004).Photographs were taken with a Canon EOS Kiss X1 with a macro lens MP-E 65, and then combined by the automontage software CombineZM.Specimens are deposited in the senior author's collection in the Kyushu University Museum (KUM) and in the Bavarian State Collection of Zoology (Munich, Germany).Measurements are given in millimeters and are abbreviated as follows: antennal length (AL); body length (BL); fore body length, from front margin of head to apices of elytra (FBL); hind tibial length (HTL); head length (HL); head width HW); pronotal length (PL); pronotal width (PW).

Leptogenys distinguenda is sometimes treated as a subspecies of L. processionalis Jerdon, 1851 known from India (Emery 1911;Bolton 1995).However, the taxonomy of Leptogenys species in Asia has been poorly studied, and identifi cations of the known species remain confusing (Ito pers.comm.).We tentatively follow the current papers citing L. distinguenda as a distinct species (e.g., Witte and Maschwitz 2000), until a revisional study of all Asian Leptogenys species is completed.Both of the ant species in the present paper are illustrated (Figs 1-4) to specify our identifi cations of the species.


Maschwitzia Kistner, 1989

Fig. 5 Maschwitzia Kistner, 1989: 301 (original description).Kistner, 1989.Diagnosis.Th is genus is closely allied to Witteia in general appearance, especially pronotal shape, but may easily be distinguished from it by having a generalized labrum, not strongly sclerotized and without projections; the simple mandibles, their inner edges not emarginate at middle; the straight lateral projections of the labial apodeme; the much s

shorter antennae; and the shorter
legs.


Type species. Maschwitzia ulrichi

Comments.Kistner et al. (2008) transferred Trachydonia aenictophila Kistner, 1997 andT. dichthadiaphila Kistner, 2003 to Maschwitzia.However, they are apparently not members of Maschwitzia, nor even closely related in view of the absence of the autapomorphies of Wroughtonilla Wasmann, 1899 and its allied genera (see Discussion).Th ough the genus Zyras Stephens, 1835 is heterogeneous, apparently non-monophyletic and not well defi ned yet, they can be placed in Zyras (s.lat.) by sharing the general diagnostic features of the genus (e.g., Fenyes 1920) and excluded from Maschwitzia, as follows:

Zyras (s.lat.) aenictophila (Kistner in Kistner et al. 1997), comb.n.Zyras (s.lat.) dichthadiaphila (Kistner in Kistner et al. 2003), comb.n.Trachydonia Bernhauer, 1928 has been placed as a subgenus of Zyras, but Kistner et al. (2003) raised it to generic status.At least Zyras aenictophila and Z. dichthadiaphila are not members of Trachydonia.Th ey are also not members of the subgenus Zyras.Th e genus Zyras should be subdivided into several genera based on a phylogenetic analysis, and then adequate systematic affi liation of t ese two species may be found.

Th e following four species are known in Maschwitzia.


Maschwitzia ulrichi Kistner, 1989

Fig. 5 Maschwitzia ulrichi Kistner, 1989: 307 (original description).Diagnosis.Th is species is closely similar to M. watanabei in general appearance, but is distinguished from it by the pronotum being narrower around the posterior margin and the aedeagus being diff erent in shape, especially with the apical part o

the median lobe bein
strongly widened apically and not excavated paramerally.Comments.Two specimens were collected for the fi rst time from the end of a migration column of Leptogenys mutabilis (new host record).(Pace, 1984), comb.n.Pace, 1984: 460 (original description).


Maschwitzia derougemonti


Wroughtonilla derougemonti


Type locality. Kalaw, Myanmar

Distribution.Myanmar.Symbiotic host.Unknown.

Diagnosis.Th e aedeagal shape is clearly diff erent from the other congeners in particular the parameral crest is larger and the apical lobe longer.

Comments.Only the holotype and one paratype are known.Th e original description by Pa

r congeners.Th e symbiotic hos
is probably, Leptogenys distinguenda or its related species.However, Asian species of Leptogenys are in need of revision, and distributions of most known species, including L. distinguenda, are sti l uncertain.(Maruyama, 2004), comb.n.Maruyama, 2004: 92 (original description).


Maschwitzia watanabei


Wroughtonilla watanabei

Type locality.Bolikhamsai (Borikhamxay), Laos.

Distribution.Laos.Symbiotic host.Unknown.

Diagnosis.Th is species is closely similar to M. ulrichi in general appearance, but is distinguished from it by the pronotum being wider around the posterior margin and by the diff erent shape of the aedeagus, especially the apical part o

ss widened apically and
argely excavated paramerally.

Comments.Only the holotype is known.Th e symbiotic host is probably Leptogenys distinguenda or a related species, although L. distinguenda is not recorded from Laos at present.Type locality.Umran, East Khasi Hills, Meghalaya, India.

Distribution.Meghalaya, India.Symbiotic host.Unknown.


Diagnosis.

Th is species is closely similar to M. ulrichi in general appearance, but is dist nguished from it by the pronotum being wider around the posterior margin and by the diff erent shape of aedeagus, especially the apical part of the median lobe being less widened apically and l

lly.

Comme
ts.Only the holotype has been known.Th e original description by Pace (2005) agrees well with the characteristics of the other congeners and he noted that this species is allied to M. derougemonti.Th e symbiotic host is probably Leptogenys distinguenda or a related species.


Togpelenys Kistner, 1989

Fi . 6 Togpelenys Kistner, 1989: 308 (original description).

Type species.Togpelenys gigantea Kistner, 1989.

Diagnosis.Th is genus is clearly distinguished from the other genera of Wroughtonilla group by the combination of the following character states: eyes extremely large; pronotum without superior marginal line of the pronotal hypomeron; pronotal disc quite convex, with a shallow and large longitudinal depression; pronotum and elytra covered with long, suberect macrosetae; and abdomen large, expanded, much wider than elytra.

Distribution.Peninsular Malaysia.

Comments.Only the type species T. gigantea Kistner, 1989 has been known in the genus.Probably further species will be found from the regions around Peninsular Malaysia, e.g., Sumatra, Borneo and Java.


Togpelenys gig

ogpelenys gigantea Kistner, 1989:
12 (original  Comments.Rare species newly recorded from Pahang.In the type locality, Ulu Gombak, Selangor, no additional specimen has been collected despite more than 40 colonies having been examined in the last few years (von Beeren and Witte, personal observations; the type series were collected in 1982).We are not sure whether this is due to environmental changes in Ulu Gombak or simply due to rarity of this species.Etymology.Dedicated to Dr. Volker Witte f

his contribution to
the biology of Leptogenys ants and their symbionts.Gender, feminine.


Witteia

Diagnosis.Th is genus is similar to Maschwitzia Kistner, 1989 in body shape and punctation of body surface, but may easily be distinguished from it by the labrum being strongly sclerotized and with a pair of spines; the inner margins of the mandibles emarginate at middle; the lateral projections of the labial apodeme curved apically; the extremely large eyes; the longer antennae; and the longer legs.

Description.Body (Fig. 7) elongate, fl attened; surface of fore body (Fig. 8) weakly rugose, reticulated, somewhat matte.

Head (Figs 7-8) transverse, with eyes extremely large, somewhat shorter than head, with a round depression above; clypeus truncate apically.Labrum (Figs 8-9) strongly sclerotized, with a pair of projections late
ll members of this genus-group are associated with Leptogenys ants as far as known, except for species of Aenictonia and Anommatochara which are associated with Dorylus Fabricius, 1793 and/or Aenictus Shuckard, 1840 ants.
h e genera of this group share the following apomorphic character states: head with "neck", a constricted postoccipital suture; pronotum with a longitudina median groove; elytra with a pair of carinae laterally; and apical lobe of aedeagal median lobe elongate.


Witteia borneensis


Wroughtonilla borneensis

When Hlaváè and Janda ( 2009) described the genus Leptogenopapus (s

ogenys brev
ceps Viehmeyer, 1914), they stated that it is closely related to Leptogenoxenus.However, Leptogenopapus does not share the character states mentioned above.Because the type species Leptogenopapus mirabilis is in its general appearance extremely modifi ed for myrmecomorphy, it is possible that the apomorphic character states in the Wroughtonilla group cited above have been secondarily lost or modifi ed in this species.However, the aedeagal shape, which is normally not modifi ed along with modifi cation of external morphology to the myrmecophilous habitat, of Leptogenopapus mirabilis is