Macrosaccus robiniella
Locust leafminer ( Phyllonorycter robiniella )
The locust leafminer ( Phyllonorycter robiniella ) is a butterfly of the family of leaf miners ( Gracillariidae ).
Features
The moths of the locust leaf miner are among the small butterflies and reach a size of about three millimeters. On the upper wing surface, the moths have an orange -and-white drawings, which are separated by black lines.
Dissemination
The locust leafminer was originally native to North America and Europe first was found in 1983 near Basel. Further dissemination:
After Phyllonorycter robiniella Hungary had reached the further spread increased significantly. Within just two years, laid the way back the 500 km target distance between the western boundary and the eastern border of the country, as the black locust is practically spread throughout the country.
Biology
The caterpillars live monophagous on the leaves of ordinary black locust (Robinia pseudoacacia). After mating, the females lay the elongated gray-green eggs on the underside of leaves. The white beads lay on the underside of leaves of black locust ordinary first a brief transitional mine. Later to become an oval space mine and at the end of a large, white folding mine. Often eat two to three beads together in an enlarged mine. The larvae go through to pupation five to six larval stages, the entire development takes about five to 11 weeks. The adults overwinter the last generation. The locust leafminer forms in Central Europe two or three generations (early summer, early fall ) per year.
One reason for the rapid spread of the locust leafminer is the fact that it is the caterpillar food plant is a neophyte, with the native fauna know little to begin with. Therefore, the caterpillars live relatively undisturbed, which contributes to its spread. The effects on the tree exist in leaf discoloration and losses, but apparently even in heavy infestation posing no serious hazard for the tree. Definitive statements about the long-term effect on the tree are, however, not yet available.
From the literature, various species of wasps are known to parasitize the caterpillars. It involves parasitic wasps species of the families of the chalcid ( Eulophidae ) and the Brackwespen ( Braconidae ).