Megalara garuda, a new genus and species of larrine wasps from Indonesia (Larrinae, Crabronidae, Hymenoptera)

Abstract A new genus and species, Megalara garuda is described from Sulawesi (Indonesia). The new species is one the largest known members of the crabronid subfamily Larrinae. It has a unique suite of putatively apomorphic morphological characters and is most closely related to the genus Paraliris. We found indications of a significant allometric variation in body size and mandibular length and shape in male Megalara, and the presence of acarinaria at least in females of the new genus. Allometric variation and acarinaria have previously been shown to occur in Paraliris, which is another indication for a close relationship of Megalara and Paraliris.


Introduction
A survey of the Mekongga Mountains and Papalia west and south of Kendari in southeastern Sulawesi uncovered a spectacular new genus and species of larrine crabronid. This new species was also independently discovered among unidentified, historical apoid wasps in the Museum fuer naturkunde in Berlin. It appears to be most closely related to the Southeast Asian genera Dalara and Paraliris. Dalara contains two species, mandibularis (F. X. Williams) from the Philippines and schlegelii (Ritsema) from Sumatra and Paraliris has four currently known species, faceta (Bingham) from India and Burma, kriechbaumeri Kohl from Java, sycorax (F. Smith) and truncatus van der Vecht, both from Borneo.
This new species from Sulawesi is among the largest members of the Larrini, with the majority of males greater than 3 cm in length. Only some Liris are as long as 30 mm (Menke in Bohart and Menke 1976). Two male morphs were discovered. One about the size of the females and the other much larger with exaggerated male features, such as the length and tooth development of the mandibles, flattening of the face and prolongation of the gena and vertex. The biology of this new genus is unknown.

Materials and methods
Mekongga and Papalia specimens were collected in Townes-style Malaise traps. Specimen images were taken with a Nikon D300 digital camera and assembled using the CombineZM software™. The holotype is deposited in the Museum Zoologicum Bogorense, Chibinong, Indonesia. Paratypes are deposited in the Museum fuer Naturkunde, Berlin, Germany, the Bohart Museum of Entomology, University of California, Davis, USA; Museum Zoologicum Bogorense, and the National Museum of Natural History (Naturalis), Leiden, the Netherlands.  (Pulawski 2011) based on the presence of a horizontal swelling below the midocellus combined with a vertical swelling along the inner eye margin. The new genus is similar to Dalara and Paraliris in having the mandibles bidentate apically or very long, at most with a weak notch on outer margin. Within this group of genera, Megalara can be distinguished by the large body size (25-34 mm; 20-24 mm in Paraliris). A unique character of Megalara is the markedly developed malar space, whereas all other genera in the Larrina have the malar space narrow or virtually absent. Additionally, the propodeal dorsum is punctate in Megalara, but finely, transversely striatorugose in Dalara and Paraliris. A subsidiary recognition character is the dark body pubescence, which is markedly developed in females, but indistinct in males (body covered with dense, silvery pubescence in Paraliris, erect pubescence lacking at all in Dalara).

Megalara
Males of Megalara have a number of complementary diagnostic characters: One of the most remarkable characters is the enormously enlarged male mandibles, which are almost as long as the forelegs. All species of Dalara and some of Paraliris also have elongate mandibles in the males, but shape and dentition are different. In Megalara, the mandibular apex is simple and the inner, subbasal tooth is greatly enlarged. In Dalara, the male mandible has one small subapical and one large subbasal tooth, whereas in Paraliris, the mandible is broadly bidentate apically in minor males and lacks subapical and subbasal teeth in major males with elongate mandibles. Other male characters diagnostic for Megalara are the hindfemoral venter, which is longitudinally compressed (evenly, slightly convex in Paraliris, with a hook-like process or prominent bulge toward base in Dalara), metasomal sterna III-IV with paired submedial lobes (simple in Paraliris and Dalara), sternum VIII bilobed apically (truncate in Paraliris, roundly truncate with a small median notch in Dalara), and the penis valve with a longitudinal row of markedly strong teeth on the ventral side (in Paraliris, penis valve with inwards directed apical and medial process, without ventral teeth).
Females of Megalara and Paraliris are generally quite similar and can be distinguished by the larger body size of Megalara, the dark pubescence in Megalara (silvery in Paraliris), and the propodeal dorsum, which is punctate in Megalara and finely, transversely striatorugose in Paraliris. Female Megalara and Dalara can be readily differentiated by dull or weakly, shining virtually asetose metasomal terga and the significantly different body sizes. Discussion. Dalara, Paraliris, and Megalara, the newly described genus, share many morphological details with Liris. Menke in Bohart and Menke (1976) said that Dalara 'possibly should be considered as a subgenus of Liris … although the biology argues otherwise'. Liris is a morphologically diverse genus and has been split up into several genera or subgenera by various authors in the past (see Bohart and Menke 1976, for a taxonomic summary). It includes more than 310 currently valid species and its monophyly has never been formally tested. The newly described species, M. garuda, shares a number of significant characters with Paraliris, and we have considered placing M. garuda as an aberrant species in this genus. However, despite the similarities, the morphological differences are so striking, that we feel that the systematic position quite apart from all other species in Paraliris is best reflected by placing it in a genus of its own. Thus despite the lack of a comprehensive phylogenetic analysis of the genera in the Larrini, Dalara, Paraliris, and Megalara each exhibit a unique set of putatively apomorphic characters, so that the taxonomic status of all of them as distinct genera seems to be fully justified. However, a formal phylogenetic analysis of the Larrini on the genus level is desperately needed to test this assumption.

Partial modification of the key to Old World genera of Larrini by Bohart and
The enormously enlarged male mandibles of Megalara are quite similar to that of male Dalara, but Megalara is more similar to Paraliris in most details. Paraliris has been revised by van der Vecht (1982), and one of us (MO) reexamined most of the specimens of the genus, which van der Vecht studied. Van der Vecht pointed out that males of at least P. kriechbaumeri, show a remarkable amount of allometric variation with respect to general body size and mandibular length. Male body length varies from 15 to 22 mm, and the mandibles of the smallest males are very similar to female mandibles in being stout and broadly bidentate apically, whereas the mandibles of the largest males are elongate, sickle-shaped and simply apically and basally (van der Vecht 1982: Figs 2-4). Despite these enormous differences particularly in mandibular size and shape, van der Vecht felt confident, based on a study by de Beaumont (1943), that this represents an unusually broad range of intraspecific variation.
This hypothesis seems to be well founded, and we observe the same phenomenon in the newly described Megalara. There are two male morphs with remarkable dif-ferences in body size and mandibular size. Minor males, which have relatively short, female-like mandibles, are 25 mm long, whereas major males with exaggerated mandibles have a body length of 32 to 34 mm. However, the genital foramen and genital capsule of the minor male was packed with mites and it may also be that this individual was feminized by the heavy mite load. Unfortunately, the genital capsule was lost. Van der Vecht (1982) also pointed out that Paraliris bears 'acarinaria', which are specialized, typically pouch-like structures in aculeate Hymenoptera, which function to carry phoretic mites. In Paraliris, acarinaria are located beneath a lamella near the base of terga II-V (females) and II-VI (males). These areas are dorsally covered by the overhanging posterior margin of the tergum before the acarinaria-carrying tergum. Therefore, if present, phoretic mites in acarinaria can be seen in the intersegmental gap beneath the tergal overhang even in complete specimens. In Megalara, we observed mites in both sexes as follows: Males. 1 major male: 2 mites between terga II and III Minor male: genitalia packed with mites Females. 1 female: 10 mites between terga II and III 1 female: 16 mites between terga II and III, 6 between III and IV The presence of two mites on the terga and the large number in the genitalia in males are probably no indication of acarinaria in Megalara. However, the large number of mites in the females indicates that Megalara also possesses mite-bearing structures. Due to the small number of specimens of the new species, we refrained from dissecting the type specimens to verify the presence of acarinaria. Presence of acarinaria in Paraliris and putatively in Megalara also is another indication of the close relationships between these genera.
Etymology. The new genus name is an arbitrary combination of Mega-, deriving from the Greek megas, meaning large and mighty, and -lara, the last syllable of Dalara. It is an allusion both to the exaggerated body size of the new genus and its overall similarity to Dalara. Description. Male (major). Body length 32-34 mm (side view, Fig. 1). Forewing 24-25 mm. Head (Fig. 3): face strongly concave at antennal sockets; clypeus 3.5× as broad as long, flattened medially with sublateral tooth on apical margin, concave between; frons bulging with strong longitudinal swelling on either side of midocellus; hindocelli tiny circular; vertex swollen above hindocelli with medial longitudinal groove terminating in deep pit; gena expanded, wider than eye in lateral view; mandibles enlarged and elongate, apex reaching lower one-third of eye when closed, subsidi- ary tooth subbasal and projecting anteriorly, mandible widest subapically, longer than head in front view; occiput deeply concave; genal bridge forming apical lobe; antenna slender, flagellomere I 4× as long as broad, flagellomere II 3.6× as long as broad, flagellomere III 3.4× as long as broad, flagellomere XI 3.5× as long as broad; with weak placoids on flagellomeres III-XI; head shiny, nearly impunctate, punctures tiny, scattered; mandible highly polished; wing apices finely plicate.
Male (minor) (Features that differ from major males). Body length 25 mm. Forewing 21 mm. Mandible shorter than head in front view; clypeus 2.7× as long as broad; flagellomere I 3.6× as long as broad; flagellomere II 3.2× as long as broad; flagellomere III 2.8× as long as broad; flagellomere XI 3× as long as broad.