Megamymar Huber, 2022

Huber, John T. & Read, Jennifer D., 2022, Three new genera of Mymaridae (Hymenoptera) from the Neotropical region, Journal of Hymenoptera Research 92, pp. 1-21 : 1

Megamymar Huber gen. nov.

Fig. 1

Type species.

Megamymar waorani Huber, here designated.

Diagnosis.

With the following combination of features: body huge (for a fairyfly), together with exserted section of the ovipositor well over 9 mm long; median ocellus abutting transverse trabecula; petiole distinctly shorter than gaster and, in dorsal view, completely hidden; metatarsus 1 longer than metatibia; gaster extending as horn anterodorsal to mesosoma.

Description.

Female. Head. Head slightly wider than mesosoma (21: 20), ~1.4 × as wide as long, ~1.1 × as wide as high and almost 1.25 × as high as long, measured laterally; transverse trabecula entirely dark; supraorbital trabecula with well sclerotized (dark) anterior half short, extending posteriorly only to level of posterior margin of median ocellus, then continuing posteriorly as poorly sclerotized (light) section extending as far as anterior margin of lateral ocellus and further continuing obliquely towards but not reaching occipital foramen as a faint, fine line. Face ~0.5 × as wide as high, in lateral view upper face receding to transverse trabecula and lower face flat and, in anterior view, with distinct depression medially dorsal to oral cavity and short, narrow vertical depression ventral to torulus; torulus ~0.5 × its own height from transverse trabecula; preorbital sulci slightly converging medially just ventral to toruli then continuing straight ventrally to dorsolateral angle of oral cavity. Compound eye slightly shorter than malar space and apparently with very few short setae among the ommatidia. Vertex in lateral view slightly curved, posteriorly merging smoothly with occiput; median ocellus abutting transverse trabecula; POL 2.0 × LOL and ~1.7 × OOL. Gena ventrally in lateral view longer than eye length but dorsally much shorter. Back of head without sulci and oral cavity well separated from occipital foramen. Antenna. Scape with radicle barely differentiated; funicle 6-segmented; clava 1-segmented. Mouthparts. Mandibles apparently with 3 teeth, meeting when closed. Mesosoma. Mesosoma almost 2.6 × as long as wide, almost 3.2 × as long as high, and ~0.8 × as wide as high. Pronotum entire, in lateral view almost horizontal, with flat dorsum, in dorsal view triangular and, including neck, almost as long as mesoscutum. Prosternum ~1.3 × as long as wide, and entire. Mesoscutum just over 2.0 × as long as scutellum + frenum, in lateral view flat; notauli incomplete, ~0.3 as long as mesoscutum as measured from their junction with anterior margin. Scutellum ~4.0 × as long as poorly defined frenum; axilla barely advanced, each ~1.0 × as wide as long. Metanotum slightly longer than frenum, without obvious dorsellum. Propodeum slightly longer than scutellum + frenum, with a shallow and narrow longitudinal median depression, in lateral view almost horizontal; spiracle in a shallow wide depression. Wings. Fore wing fairly wide, with apex rounded and slightly asymmetrical, and with almost straight margin behind venation; venation ~0.2 × as long as wing length; parastigma with proximal but apparently without distal macrochaetae, with hypochaeta next to proximal macrochaeta. Hind wing narrow and almost straight. Legs. Legs long; tarsi 4-segmented, with tarsomere 1 of all legs longer than tibiae. Metasoma. Metasoma ~2.3 × as long as mesosoma (Fig. 1 ). Petiole ~3.4 × as long as wide, in dorsal view hidden by anterior extension of gaster. Gaster (measured to anterior apex of anteriorly truncate dorsal horn) ~6.4 × as long as wide and ~1.2 × as high as wide; gt5 apparently the longest tergum (Fig. 1 ). Ovipositor with exserted portion extremely long.

Male. Unknown.

Derivation of genus name.

A euphonious combination from Greek: megas, meaning large, and Mymar, the name of the type genus of Mymaridae . The genus name is neuter. Mega refers to the large body of the only known species of the genus, which is over 1 mm longer than the next longest Neotropical species, Erdosiella mira (Annecke & Doutt), whose body length is 3.7 mm.

Relationships.

Megamymar is best placed in Mymarini sensu Annecke and Doutt (1961) because of the combination of 6-segmented funicle, 4-segmented tarsi and distinctly petiolate gaster. Among the genera of Mymarini , the supraorbital trabecula extending posteriorly only to the level of the median ocellus, the fore wing shape, short fringe setae and venation with relatively long parastigma indicate that Megamymar is most closely related to Erdosiella Soyka and Tanyostethium Yoshimoto in the New World, and perhaps Narayanella Subba Rao in the Old World. Megamymar is clearly separated from these three genera by the petiole much shorter than the gaster and the anterodorsal extension of the base of the gaster over the apex of the propodeum; none of their species have this combination of features. Instead, in these genera the supraorbital trabecula extends to about the level of the lateral ocelli, the petiole is usually as long or longer than the gaster, and gt1 does not project anteriorly over the propodeum though occasionally the base of gt1 may slant slightly anteriorly before receding uniformly and smoothly posteriorly to the anterior margin of gt2. It could perhaps be argued that the features of Megamymar are just one of degree rather than substance and therefore Megamymar should be treated as just an extreme representative of Erdosiella , but then many of the numerous genera of Mymarini should be placed in synonymy under one another as well. Whether such an approach would clarify generic relationships within Mymarini is debatable.

Megamymar superficially resembles several of the largest species of Australomymar Girault and the extralimital genera Borneomymar Huber, Neotriadomerus Huber and Paranaphoidea Girault. At least some species in all these genera, none of which are mophologically closely related to Megamymar , have a long ovipositor often greatly exserted posteriorly ( Australomymar , Borneomymar , Polynemoidea Girault) or anteriorly ( Neotriadomerus ). In the Neotropical region, Australomymar appears superficially to be the most similar looking genus but the body of the largest species is at most ~3.0 mm long and the base of the female gaster does not extend anteriorly in a dorsal horn (the gastral sac). In other genera of Mymaridae the ovipositor may extend anteriorly but it is always ventral to the mesosoma.

Figures

Figure 1. Megamymar waorani Huber, holotype female, lateral habitus (ovipositor photoshopped to curve downward to fit page better).