Biological parameters and control of the eucalyptus red gum lerp psyllid, Glycaspis brimblecombei Moore (Hemiptera: Psyllidae), in Greece

The eucalyptus redgum lerp psyllid (RGLP), Glycaspis brimblecombei Moore (Hemiptera: Psyllidae) is one of the 137 species of GlycaspisTaylor genus. It firstly recorded in Australia and later on, it spread in some regions of America. Due to the extensive defoliation it causes, it is considered as a serious pests and, as a result, in 2002 it was included in the EPPO’s quarantine species list. In Europe, its first official record was in 2007, in the Iberian Peninsula, while in June 2010 it was found in Italy (Campania region). In Greece, although it was officially first observed in 2013, it is likely that it existed in the country for more than a year prior to its first record, given that it was encountered at the same time in many areas of the West, Central as well as South Greece.

Psyllid adults are highly mobile, about 3mm long, alates, with white and yellow color on their thorax and head, while the abdomen is greenish. The females lay their eggs solitary, or in loose groups on both leaf sides. The eggs are of orange and yellow color, stalked and about 1mm in length. It forms 5 nymphal instars, from which the last 4 live and develop inside a crystalline, semi- transparent lerp they create. The lerp is a white conical construction that the nymph creates from honeydew and other waxy secretions, in order to be protected from enemies and uncomfortable environmental conditions.

The aim of this study was to observe RGLP’s population density on eucalyptus, as well as to evaluate the effectiveness of synthetic chemical insecticides and plant extracts on RGLP control. For this reason, from April to November 2014 samplings were taking place in 3 areas of Attiki region, Central Greece. In each sampling, eucalyptus stems were collected, each containing 15 leaves. The collected stems were transferred to the Laboratory of Agricultural Zoology and Entomology of the Agricultural University of Athens, for stereoscope observation. Psyllid individuals of all stages and conditions (alive, dead as well as parasitized) were counted and population curves were created. Also, bioassays were conducted by using eucalyptus leaves with RGLP individuals, placed in Petri dishes with dumbed cotton and filter paper as substance. These leave were sprayed with insecticide solutions and kept in controlled room conditions, where they were inspected daily for insect survival. Sprayings included the synthetic a.i. spirotetramat, l-cyhalothrin, abamectin and thiamethoxam, as well as extracts from the plants Melia azedarach, Urginea maritima, Ailanthus altissima and Ecballium elaterium. Detailed results will be presented and discussed.