Ponometia tortricina (Zeller)
Diagnosis: Ponometia tortricina is a variable species with three general forms. In the first form the male forewing is yellow with a slightly greenish overtint. The orbicular is a small, black dot and the reniform varies from absent to a smaller dot than the orbicular. A broad half-band arises from the inner margin of the wing ending just before the position of the renifrom This band is variable ranging between a distinct rectangle with a dark brown inner margin to a much weaker wavy line representing only the postmedial line. The second basic form of tortricina has a general dusting of gray scales. The hindwing is sufused with gray-brown. Finally the third form is a uniform light gray-brown, but still with a slightly green tinge to the forewing in fresh specimens. Females, general, are darker than the males with the maculation less distinct and with a general smattering of gray-brown scales. Individuals also exist that a light pale brown with only a hint of the green-yellow showing through.
The male genitalia have triangular projections from the costa. The projection on the right valve (in the orientation of the picture) is pointed and exceeds the lower margin of the valve. The projection of the left valve is rounded and does not exceed the lower margin.
Specimens from the northern prairie provinces of Canada usually have a distinct orange tint to part of the maculation.
Wing expanse from base to apex in one selected individual 9 mm.
Distribution: (Based only on material in the USNM). Ponometia tortricina has a wide distribution and is absent only from the eastern parts of the United States. It occupies the midwestern parts of Canada and the United States and reaches northward into central Alberta. Its western range occupies the Great Basin Region and extends as far west as eastern Washington, Oregon, and northern Nevada.
Identification Quality: Fair to poor. The relationship between tortricina and fumata is still problematic. The forewing of tortricina almost always has a greenish tinge, even in those specimens suffused with grayish brown. A greenish tinge is absent in all specimens identified as fumata. However, both species are variable in both color, geographically and individually. Yellow specimens of tortricina are easily separated from fumata. However specimens of tortricina heavily suffused with gray-brown can be nearly impossible to separate from fumata, particularly in the specimens are old and faded. There are no apparent significant differences in the male genitalia. However the female genitalia are abundantly distinct, particular in the shape of the bursae and the extent of the heavy sclerotization. The species appear to be sympatric in the Great Basin region of the United States. Never the less much more research needs to be done to clarify the relationship between these two supposed species.
Distribution map based on specimens in the USNM
See discussion under Indentification Quality above.