Genus Pseudonapomyza

Pseudonapomyza Hendel, 1920

The small genus consists of two distinct subgroups. One group consists of leaf miners feeding on the plant families Acanthaceae and some others; the other larger group contains grass mining species. Species of the latter group sometimes cause damage on cultivated fodder grasses and cereals. The phylogenetic position of this, exclusively leaf-mining group is not yet clarified. There are only grass miners, which are of economic interest. Therefore the focus in this section is on the grass mining species.

Recent taxonomical studies (Spencer, 1990; Cerny, 1992; Zlobin, 1993 a,b) suggest, that several undescribed species do exist and that some previously described species are actually species groups. Thus, literature data on host specificity, distribution and bionomics should be handled with care. A thorough study including older and fresh material is strongly required.

Costa extending only to R 4+5 (as many other genera); second costal section conspicuously short, less than 1.5 times length of 4th (Spencer, 1986); cross vein m-m is missing (wing Pseudonapomyza.pct); the third antennal segment is angulate (Ps atra antenna.pct) (only true for species feeding on Poaceae).
Mesonotum and abdominal tergites often with bluish glimmer. Grass feeders: Only three postsutural dorsocentral bristles (dc), sometimes a very small fourth, presutural dc may occur.

Male terminalia
Epandrium long, fused surstyli (Pseu europaea epandrium.pct); hypandrium rather short with a broad frame. Aedeagal apodeme often long (Pseu europaea genitalia.pct). Tip of aedeagus at most strongly pigmented, with well visible appendages of distiphallus (Pseu europaea aedeagus exp.pct).

Immature stages
The mandibles normally have each two alternating mouth hooks. On each segment are one or more rows of conspicuous setae (Pseu atra puparium.pct). Pupariation often but not always takes place in the mine.

Bionomics of grass mining Pseudonapomyza
The host range from many species is not exactly known. Most grass mining species appear to feed on several wild grasses as well as on more than one crop species. Among the cultivated host plants are Oryza sativa (rice) (Khan et al., 1956; Barrion and Litsinger, 1979; Zea mays (maize) (Reddy, 1956, El-Sherif et al., 1978); Sorghum spec. (sorghum) (El-Sherif et al., 1978) and several European cereals.

Economical importance
Several grass mining species are known to occur on cultivated crops as maize, rice and barley.
There are many undescribed species on wild grasses, especially in Africa, many of these may also occur on cultivated crops. Grass feeder are generally not very specific. It should be expected that several species could occur on the same plant.