Genus Leptophion Cameron, 1901

Leptophion Cameron, 1901: 227 . Type species: Leptophion longiventris Cameron, by monotypy. Spilophion Cameron, 1905: 124. Type species: Spilophion maculipennis Cameron, by monotypy. Synonymized by Townes et al. (1961: 265).

Coiloneura Szépligeti, 1905: 35. Type species: Coiloneura melanostigma Szépligeti, by subsequent designation. Synonymized by Cushman (1947: 462).

Diagnosis. This genus can be distinguished from other genera of Ophioninae by the following combination of character states: (1) mandible not twisted, barely tapered, with symmetric teeth or upper tooth slightly longer than lower one, usually with a swelling and oblique groove on its basal surface (Figs 1, 8, 10, 16, 18, 25, 27); (2) in lateral view, clypeus strongly convex, its lower part abruptly strongly curved backward (Figs 10, 18, 27) and in frontal profile its lower margin nearly straight (Figs 1, 8, 16, 25); (3) occipital carina complete except for lower end absent and not joined to hypostomal carina and base of mandible (Figs 9, 10, 17, 18, 26, 27); (4) ocelli large and posterior ones adjacent with eyes (Figs 1, 8–10, 16–18, 25–27); (5) posterior transverse carina on mesosternum complete, rarely interrupted in a few Australasian species (i.e., L. anici Gauld, 1977, and L. antennatus (Morley, 1912)); (6) notauli faintly present as vestiges or completely absent (Figs 11, 19, 28); (7) epicnemial carina on mesopleuron present and its upper end reaching above level of lower margin of pronotum (Figs 11, 19, 28); (8) anterior transverse carina on propodeum developed but in a few species its outer end absent (Figs 11, 12, 19, 20, 28, 29); (9) posterior transverse carina on propodeum virtually absent but often with vestiges laterally (Figs 11, 12, 19, 20, 28, 29); (10) fore wing with a glabrous area on anterior corner of discosubmarginal cell, and virtually all species without sclerites there, except for a Filipino species, L. pterospilus Gauld & Mitchell, 1981, which has a distinct sclerite; (11) 1m-cu on fore wing sinuous or curved, usually without ramellus (Figs 2, 32–34); (12) hind wing usually with an apparently elongated penultimate hamulus on R1 (Fig. 13), while occasionally with uniform hamuli (Figs 21, 30); (13) tibial spur of fore leg without a membranous flange; (14) mid and hind trochanters simple; and (15) distal pecten of hind tarsal claw developed and significantly longer than true apex of claw (Figs 14, 22, 31).

Distribution. Australasian, Oceanic, Oriental, and Palaearctic regions (Gauld 1977; Gauld & Mitchell 1981; Shimizu & Watanabe 2015a).

Bionomics. Host is unknown. Adult wasps are often collected in LT in rainforests.

Remarks. Most Leptophion species are known from the Australasian region while only a few species are distributed in the Oceanic and Oriental regions and the southeastern part of the Palaearctic region.

In Taiwan, three species (i.e., L. maculipennis of the maculipennis species-complex, and L. radiatus and L. giganteus Shimizu & Watanabe, sp. nov., both of which belong to the radiatus species-complex) are found (Gauld & Mitchell 1981; Shimizu & Watanabe 2015a, b) and they can easily be distinguished from each other by the following key.