Tetrastichus Haliday, 1844

Hansson, Christer & Schmidt, Stefan, 2020, A revision of European species of the genus Tetrastichus Haliday (Hymenoptera: Eulophidae) using integrative taxonomy, Biodiversity Data Journal 8, pp. 59177-59177 : 59177

Tetrastichus Haliday, 1844

Tetrastichus Haliday 1844:297-298. Type species Cirrospilus attalus Walker, by monotypy (= T. miser (Nees)). Not Tetrastichus Walker 1842:116, a name suppressed by the International Commission on Zoological Nomenclature (1965).

Tetrastichus Graham (1991)

Tetrastichus

Diagnosis

European species of Tetrastichus can be diagnosed by a combination of three features: submarginal vein in fore wing with one dorsal seta, mid-lobe of mesoscutum with at least three adnotaular setae on each side and propodeum with a ± complete lateral longitudinal carina that splits into two in posterior part (like an inverted "Y", Fig. 2 c). In addition, most species have a strong exoskeleton, preventing specimens from collapsing when dried. This last feature is not unique to Tetrastichus , but in combination with the other three features, it helps when diagnosing this group.

Identification keys

Figs 2, 3:The identification keys are based on the two keys in Graham (1991), one for females and one for males, with the new species included and with some modifications of features included and order of couplets slightly changed. The main reason for keeping the sexes apart is that differences between species are frequently based on features unique to each sex (antennal characteristics and length of female gaster). Since males are unknown for several of the species, the male key is distinctly shorter than the female key.