Megadiestramima (Megadiestramima) borealis, Gorochov & Storozhenko, 2019

Megadiestramima (Megadiestramima) borealis View in CoL sp. nov.

( Figs 6–10, 39)

Holotype. Male, Northern Vietnam, Lang Son Prov., Huu Lien Reserve , 200 m, primary forest, 23– 30.VII.2003, N. Orlov ( ZIN).

Paratypes. One male, 1 female, same data as for holotype ( ZIN) .

Description. Male (holotype). General appearance similar to that of M. (M.) intermedia . Colouration almost as in light specimens of this species, but with following peculiarities: most part of body light brown with large dark brown areas under eyes reaching lateral parts of clypeus, brown epicranial dorsum (behind rostral tubercles), pronotum, mesonotum and dorsal part of eight subsequent tergites (including metanotum); legs also light brown but with dark brown both apical area on each femur (except for light brown spurs) and dorsal area on proximal half of hind femur as well as with several poorly distinct darkish spots and areas on other parts of legs. Structure of body typical of this genus, however: head with rostral tubercles rather narrow (their base laterally as wide as distance between each rostral tubercle and nearest eye); apical segment of maxillary palpus almost equal to half of fore femur in length; right coxa with short spine, but left one with very short spine; hind femur with nine inner ventral non-articulated spinules and a pair of small apical denticles; armament formula of tibiae and of hind basitarsus characteristic [dea, v~2, v2, v3a / d2a, v~2, v2, v3a / d30e-27i (d30e-28i), d2sa, 6a / d1c, dac]; inner dorsal spur of hind tibia barely protruding beyond apex of dac [= unpaired (central) dorsoapical spur of hind basitarsus]; sixth abdominal tergite with very short posteromedi- an lobe; posteromedian process of seventh abdominal tergite moderately short, i.e. similar to that of M. (M.) intermedia but less wide (its width in distal part approximately two mm, but this width in M. intermedia about 3.5 mm; for comparison see Figs 1 and 6); paraproct with moderately long ventroapical process (space from cercal base to apex of paraproct about 1.8 times as long as this process; in M. intermedia , this process longer, and this ratio almost equal to two) and small but distinct convexity between base of this process and widely rounded dorsal lobe (in M. intermedia , this convexity indistinct; see Figs 2 and 7); genitalia with median sclerite well developed and distinctly Y-shaped, with distal (unpaired) part of this sclerite slightly longer than a pair of its proximal parts (i.e. this distal part slightly shorter than in M. intermedia ), and with membranous lobes larger than in this species (see Figs 37 and 39).

Variations. Colouration of second male with longer darkened apical portion of femora and more distinct (almost brown) spots on rest part of fore and middle femora; this male also with short (identical) spines on both coxae; armament of legs very weakly variable.

Female. Colouration and structure of body similar to those of holotype, but size somewhat larger, coloration barely darker but with brown apical part of each femur and dorsal surface of proximal half of middle and hind femora as well as poorly distinct darkish spots and areas on rest parts of legs, armament of legs in limits of variability in males but with slightly more numerous non-articulated dorsal spinules on hind tibia, sixth abdominal tergite almost without posteromedian lobe, seventh abdominal tergite with very short and rounded posteromedian lobe, paraproct smaller and roundly triangular as well as with small ventroapical tubercle. Genital plate indistinguishable from that of female of M. (M.) intermedia in shape, with small but distinct lateral denticles (non-articulated lateral spinules) locat- ed in distal half of this plate ( Figs 9, 10); ovipositor as in Fig. 50.

Length in mm. Body: male 17.5–23, female 24; pronotum: male 6.5–8, female 8.4; fore femur: male 13.7–17.5, female 16.7; hind femur: male 28–35, female 33; hind tibia: male 33–41, female 39; hind basitarsus: male 5.5–7, female 6.5; ovipositor 19.

Comparison. The new species is most similar to M. (M.) intermedia in the structure of male abdominal apex (including median sclerite of male genitalia) and may be only a subspecies of the latter species. Differences of M. borealis from all the other congeners are given above, in the key and description.

Etymology. This species name is the Latin word “borealis ” (northern), because it is given the species described from the most northern localities of Megadiestramima s. l.