Euphorbialygus nanglong, Yasunaga, 2024

Yasunaga, Tomohide, 2024, New genera and species of the ‘ Lygus-complex’ ranging from the Himalaya-Oriental to the Wallacea region (Insecta: Heteroptera: Miridae: Mirinae), Raffles Bulletin of Zoology 72, pp. 371-423 : 389

Euphorbialygus nanglong , new species

( Figs. 8A–D, G , 9 A−E, 10A–F, 24)

Type material. Holotype: male, THAILAND: Nakhon Nayok: Sarika near Nang Rong Waterfall along stream, 14°19′39.5″N 101°19′07.4″E, on inflorescences and flower buds of Homonoia riparia , 31 December 2012, T. Yasunaga ( DOAT) ( AMNH _ PBI 378780 ) . Paratypes: THAILAND: 3 males, 7 females, same data as for holotype ( AMNH, TYCN, ZRC); 1 male, Nakhon Ratchasima, Wang Nam Khiao, Sakaerat Environmental Research Station , 14°30′27″N, 101°55′39″E, 410 m alt., UV lighting, T. Yasunaga, 28 October 2008 ( TYCN) .

Diagnosis. This new species is recognised by the characters mentioned in the generic diagnosis but can be distinguished from the other congener, E. rufobrunneus , by its smaller size; apically situated, dark, ovoid spot on cuneus; shorter hypophysis and triangularly projected sensory lobe of left paramere; sharp, longer flagellate lobal-sclerite on vesica; distinct paired process on posterior wall; and sparsely distributed scaly microstructures on interramal lobe. The final (5th) instar immature form is recognised by its ovoid body shape; greyish dorsum speckled with reddish brown maculae; and antenna and leg with reddish brown annulations or spots ( Fig. 8D ).

Description. Body generally reddish brown or brick-red, oval, comparatively small; dorsal surface weakly shining ( Fig. 8A, C ). Head shiny reddish brown, with sparsely distributed, short, semi-erect setae; jugum and lorum whitish; clypeus dark reddish brown ( Fig. 8B ). Antenna dark brown; antennomere I pale reddish brown, with basal ⅓–½ darkened; antennomere II with pale basal half and basal dark ring; extreme base of antennomere III creamy yellow. Labium shiny pale brown, reaching or slightly exceeding apex of metacoxa; base of segments III and almost whole IV darkened ( Fig. 8B ). Pronotum shining, uniformly pale reddish brown; pleura reddish brown, partly speckled with reddish suffusions (but fading to uniformly pale brown in dry-preserved specimens); collar smooth, without micro-setae or pruinosity ( Fig. 24B, C ); ventral margin of propleuron, posterior margin of mesepisternum and metathoracic scent efferent system creamy yellow; scutellum matte, with a pair of obscure maculae ( Fig. 8A, C ). Hemelytra matte, with somewhat darkened apical part of clavus and inner part of corium; cuneus pale reddish brown, with a dark, circular spot at posterolateral margin; membrane smoky brown, tinged with red anteriorly, with pale veins. All coxae and legs pale brown, partly suffused with red; apical part of each femur more or less speckled with brown spots or maculae; each tarsomere III dark brown; pretarsal structures as in Fig. 24H . Abdomen pale reddish brown, partly with sanguineous spots. Male genitalia ( Figs. 9 A−E, 24I–K): Hypophysis of left paramere short, with hooked apex ( Fig. 9A ). Vesical spicule relatively slender, weakly curved apically; flagellate lobal-sclerite long ( Fig. 9E , 24I ). Female genitalia ( Figs. 10 A−F, 24L–O): Sclerotised rings ovoid ( Fig. 10E ); posterior wall with a pair of distinct processes anteriorly ( Fig. 24N ); interramal lobes narrow, with sparsely distributed scaly microstructures on distal ⅓ ( Fig. 24O ).

Measurements. See Table 1.

Etymology. Named after the type locality, Nanglong (Nakhon Nayok, Thailand); a noun in apposition.

Distribution. Thailand (Nakhon Nayok, Nakhon Ratchasima).

Biology. In Nakhon Nayok, central Thailand, the adults including a few teneral (freshly emerging) individuals and final instar nymph ( Fig. 8D ) were obtained from the inflorescence and flower-buds of Homonoia riparia Lour. ( Euphorbiaceae ) along a stream ( Fig. 8G ).

Figures

Fig. 8. Habitus images and habitats (G, H) of Euphorbialygus nanglong, new species from Nakhon Nayok, Thailand (A–D, G) and E. rufobrunneus, new species from Chitwan National Park, Nepal (E, F, H). A, B, Male; C, E, F, female; D, 5th instar nymph; G, Homonoia riparia; H, Mallotus sp.

Fig. 9. Male genitalia of Euphorbialygus nanglong, new species (A–E) and E. rufobrunneus, new species (F–H). A, B, F, left paramere; C, D, G, right paramere; E, H, vesica. Scale bars 0.2 mm.

Fig. 24. Scanning electron micrographs of Euphorbialygus nanglong, new species. A, head and thorax, left lateral view; B, head and anterior pronotum, left lateral view; C, head, dorsal view; D, metathoracic scent efferent system; E, scutellum, clavus and corium, dorsal view; F, pygophore, left lateral view; G, metatarsus; H, pretarsal structure of metaleg; I, vesica; J, left paramere; K, right paramere; L, genital chamber and ovipositor (gonapophysis I); M, genital chamber; N, O, posterior wall.

Fig. 10. Female genitalia of Euphorbialygus nanglong, new species (A–F) and E. rufobrunneus, new species (G–I). A, Genital chamber with ovipositors (gonapophyses II), ventral view; C, G, genital chamber, ventral view; D, ditto, dorsal view; E, sclerotised ring; F, I, posterior wall, anterior view; apex of ovipositor (gonapophysis I). Scale bars 0.2 mm.