A small delphacid planthopper described by Crawford in 1914. Known from limited records across northeastern and north-central North America. The species epithet "nigridorsum" refers to a dark or black surface. Like other delphacids, it possesses a distinctive movable spur on the hind tibia, a diagnostic feature of the .
Identification
May be distinguished from congeneric by the dark coloration implied by the specific epithet. Members of Isodelphax can be separated from other delphacid by genitalic characters, particularly male pygofer and . The hind tibial spur, characteristic of Delphacidae, is present. Specific diagnostic features for this species require examination of or original description.
Distribution
Recorded from Alberta (Canada), Colorado, Connecticut, District of Columbia, and Maine (USA).
Similar Taxa
- Isodelphax basivittaCongeneric with which it may co-occur; requires genitalic examination for reliable separation.
- Other Delphacidae generaMay be confused at superficial examination; presence of Isodelphax-specific genitalic characters and wing venation patterns distinguish the .