Trichadenotecnum marginatum

Yoshizawa, Kazunori & Lienhard, Charles, 2015, Synonymy of Cryptopsocus Li with Trichadenotecnum Enderlein (Insecta: Psocodea: ' Psocoptera': Psocidae) and description of three new species, Zootaxa 3957 (4), pp. 480-488 : 481

The marginatum group (new species group)

Diagnosis. Small psocids, forewing length about 2 mm. Forewing broadly but sparsely covered with tiny spots; pterostigma pale except for maculated distal end and posterior tip; opposite spots in cell r apparent; spot in cell a apparent; basal band running from stigmasac to distal 1/3 of cell cup, with wide transparent area around first segment of M vein; distal band apparent; spot on roof of cell m3 distinct; submarginal spots apparent but sometimes indistinct in some cells; marginal cloud almost absent, only recognizable at vein ends; vein Rs forked in right angle; areola postica almost triangular (roof veins slightly angulated); distal vein of areola postica directed posteriorly. Hindwing hyaline. Male terminalia: clunium without lateral processes nor dorsal flap; epiproct lobe weakly to well developed; paraproct with weakly developed basal process; hypandrium asymmetrical, posteromedially with wide membranous region; phallosome symmetrical. Female of this group known only from T. tigrinum , described below, therefore variation of female characters among species unknown (see description of female genitalia of this species for a preliminary diagnosis of females of this species group).

Remarks. In the original description of Cryptopsocus, Li (2002) considered the flattened posterior margin of the phallosome to be one of the diagnostic characters of the genus (in Chinese description, p. 1459). In the English diagnosis, it is described as "phallosome acute at base and apex (p. 1900)" but, judging from the illustration (fig. 1304F), the Chinese description seems correct. However, the distal part of the phallosome is highly variable among species of this group and thus this character is unsuitable for group definition. Five species are here assigned to this species group. Based on the hypandrial structures, they can be classified into two subgroups: T. marginatum , T. cynostigmus and T. tigrinum by having a movable median tongue and a right corner lacking keels or processes; T. sharkeyi and T. sabahense by having an unmovable median tongue and a highly modified right corner. The group name is based on T. marginatum , the oldest species name within the group.