Igutettix oculatus: an invasive pest of lilac
Igutettix oculatus (Hemiptera: Cicadellidae – lilac leafhopper) originates from Japan and the Russian Far East where it lives on Amurian lilac (Syringa reticulata). In the 1980s, it was introduced into European Russia probably on lilac planting material. It was first found in 1984 in a garden in Moscow, feeding mainly on Persian lilac (S. persica) and occasionally on common lilac (S. vulgaris). It continued to spread westwards in Europe and reached Belarus, Estonia, Finland, Latvia and Lithuania. In addition to an expanding geographical range, a shift in the host range also took place in Europe where I. oculatus has been observed feeding on Ligustrum vulgare and Fraxinus excelsior. In Finland, I. oculatus was first observed in 2002 in Helsinki and then in other localities in the southern part of the country. In 2012, leaf damage caused by I. oculatus was detected for the first time in Latvia during a survey on pests of ornamental plants. The insect was found in the regions of Kurzeme, Vidzeme and Zemgale on Fraxinus, Ligustrum and Syringa. In 2013, the pest was also detected in the northeastern part of Lithuania on Ligustrum vulgare and S. vulgaris. On its host plants, nymphs and adults of I. oculatus feed on the leaf underside, causing leaf discoloration. In Finland, although substantial leaf discoloration has been observed on lilac this did not lead to significant impact on plant growth. In Latvia and Lithuania, severe leaf damage (drying and dying) affecting the ornamental value of the plants has been reported on some lilac species, and damage has also been observed on the foliage of young F. excelsior trees when population densities of I. oculatus were high. For the moment, there is no information about the possible role of I. oculatus in transmitting plant diseases (e.g. phytoplasma diseases).
Sources
Gnezdilov VM (2014) Igutettix oculatus (Homoptera, Auchenorrhyncha, Cicadellidae) as invasive leafhopper species on lilac in parks of Saint Petersburg. Plant Protection News 2, 74-76 (abst.).
Maslyakov VY, Izhevsky SS (2011) [Alien phytophagous insect invasions in the European part of Russia]. IGRAS, Moscow, 272 pp (in Russian).
Söderman G (2005) The eastern Palaearctic leafhopper Igutettix oculatus (Lindberg, 1929) in Finland: morphology, phenology and feeding (Insecta, Hemiptera, Cicadellidae, Typhlocybinae). Beiträge zur Zikadenkunde 8, 1-4.
Söderman G (2007) Taxonomy, distribution, biology and conservation status of Finnish Auchenorrhyncha (Hemiptera: Fulgoromorpha et Cicadomorpha). The Finnish Environment, 101 pp.
Stalažs A (2013) The invasive lilac leafhopper, Igutettix oculatus (Lindberg, 1929), continues to spread in Europe: new host plant and new findings (Hemiptera: Cicadellidae, Typhlocybinae). Cicadina 13, 59-67.