Diagnosis - Postmarginal
vein (PMV) absent or rudimentary, at most half the length of the
stigmal vein (STV). Scutellum with two pairs of setae,
and usually with two pairs of longitudinal
lines (submedian and sublateral). Female
antenna with three funicular segments; male
antenna with four. Submarginal vein (SMV) with 1,
2,
3
or more setae on dorsal surface. Notauli
always straight and complete to hind margin of mesoscutum. Axilla
usually strongly advanced, defining a linear or almost linear scapula.
Male antennal scape with a sensory plaque
on ventral edge.
Classification and distribution
- The Tetrastichinae is one of the two largest subfamilies of the
Eulophidae, with about 1650 species in 90 genera. Members are common
and abundant in all geographic realms. It is currently divided into
two tribes: the Gyrolasomyiini contains only 2 species in one genus;
the Tetrastichini contains everything else.
Identification - Keys to
genera of Tetrastichinae are available for Australasia (Boucek,
1988), Europe (Graham, 1987;
1991) and North America (La
Salle, 1994; Schauff et
al. 1997). Gauthier
et al. (2000) provided a list all genera in this subfamily.
Noyes (2003) provided an electronic
catalogue for the entire Chalcidoidea.
Biology - Biologically the Tetrastichinae is one of the most interesting groups of Chalcidoidea. Hosts of this subfamily are found in 100 families of insects in ten different orders, in addition to spider eggs, gall-forming mites, and even nematodes; a few species are partially or completely phytophagous. The subfamily includes both ectoparasitic and endoparasitic species, although the latter appear to be more prevalent (Graham, 1987). Within the Tetrastichinae, there are only a very few genera which appear to be restricted to leafmining hosts (e.g. Minotetrastichus, Mischotetrastichus). More frequently, species which attack leafminers belong to genera with very wide host ranges (e.g. Aprostocetus, Baryscapus, Pronotalia, Quadrastichus).
