Agromyza nigrella (Rondani, 1875)
Closely related to Agromyza megalopsis.
IMPORTANT CHARACTERS
Adults
Wing length: 2.5 - 3.1 mm.
Male terminalia
Aedeagus according to Spencer, 1973 distinct (Ag nigrella aedeagus Sp.pct).
Immature stages (Spencer, 1973)
Posterior spiracles of larvae widely separated (Ag nigrella post sp Sp.pct), each one with three spiracular openings. That is the main difference between nigrella and the related Agromyza megalopsis. Puparium reddish brown.
BIONOMICS
The mines of the third instar can be very large, up to 9 cm. A. nigrella is not as well studied as the related species Agromyza megalopsis, so it is not known, to what extend the lifestyles resemble each other.
HOST PLANTS
Many wild grasses are potential host plants capable to maintain the population. The following cultivated cereals are known to be infested: Avena sativa L. (oats), Hordeum vulgare L. (barley), Secale cereale L. (rye), Triticum aestivum L. (wheat).
DISTRIBUTION
Widespread in Europe, Korea.
ECONOMIC IMPORTANCE
As far as known nigrella belongs to the more important miners on cereals. Together with other species or alone the species can cause serious damage on the leaves of cereals. However, outbreaks apparently occur only periodically or regionally (Spencer, 1973).
Despite the leaf damage, significant grain reduction is not necessarily caused.