Cerodontha dorsalis

Cerodontha (Cerodontha) dorsalis (Loew, 1863)

Color patterns variable, with a paler form mainly occurring in the eastern United States and South America and a darker mainly known from the Western part of the USA (Aldrich, 1918, Frick, 1959, Boucher, 2002). Sometimes intermediate forms were seen (Boucher, 2002).

Wing length: 2.4 - 2.9 mm. Antennae elongate with a short spine at upper corner.
Frontorbital setulae in small numbers and with different orientation. An additional minute bristle or hair above antennae can be interpreted either as a reduced frontorbital bristle or frontorbital hair. Cuticle around inner vertical bristle yellow, sometimes with a small dark patch. Notopleuron with only one posterior bristle. The former position of the remaining reduced bristle might be still visible by a darkened scar. Mesonotum subshining with fine pubescence.
Color variation
Because of the dark and pale forms, some colors are extremely variable (Boucher, 2002): The inner vertical bristles can be on yellow (pale) or dark background; the mesonotum can be dark or covered with extensive yellowish patterns, especially next to the scutellum. The same is true for the scutellum, the katepisternum and the femora which can be completely yellow or yellow with brownish striations.
Immature stages
Posterior spiracles similar to those of denticornis.

The biology was investigated in detail by Luginbill and Urbahns, 1916:
After oviposition into the leaf, the young larva mines downwards and enters the sheath of the leaf, where the main development occurs. Luginbill and Urbahns, 1916 furthermore reported, in young, tender plants the larvae can invade the stem. Pupariation occurs inside the plant. There are many overlapping generations per year.
The length of the time of larval development can vary considerably, depending on temperature and other environmental factors. Luginbill and Urbahns, 1916 reported larval periods from 9 until 16 days and puparial times of the same range.

Avena sativa L. (Oats), Hordeum vulgare L. (barley), Panicum sp. (millet), Secale cereale L. (rye), Triticum aestivum L. (wheat), Zea mays L. (maize) and many fodder and wild grasses.

North and South America, Guadeloupe; Mongolia (Spencer, 1973). Although the color variation in this species is not fully understood and some overlap occur, the dark specimens are mainly collected in the western half of North America and the pale specimens are predominant in the eastern part. Known records were mapped by Boucher, 2002.

Spencer, 1973 reported a few outbreaks of Cerodontha dorsalis in which the populations reached economic levels. Usually the species cannot be considered as serious pest although it frequently can be found on cultivated plants.