Шљивина лисна бува /Plum psyllid

In this monograph is presented the plum psyllid (Cacopsylla pruni Scopolli). It is a less known, but, from the economic point of view, a very important pest. In Serbian orchards this insect has been recorded for the first time in 1967. The author presents this species’ morphology and biology by recording its presence in orchards. In the monograph are presented its suitable reproductive hosts, the first and last occurrences in orchards and registered damage, which was aresult of their feeding. Disruption in development or finding of the plum psyllid are considered as consequences of extremely low temperatures during April, freezing rain or snow. It is highlighted that this insect, in favorable environmental conditions, can be a very important stone frui pest, as it provokes direct and indirect damage. The direct damage affects fruit bearing and is not economically important as the indirect one. The insect is a vector of stone fruit yellows phytoplasma (ESFY), which provokes decline of stone fruit (apricot, peach and plum). The cause of decline and the presence of this harmful agent have not been known until now. During the period 1997-2007, distribution of species was confirmed in the vicinity of Čačak, but it was probably present on a wider territory. In the monograph are presented results obtained by numerous researchers who monitor population number and appearance of this pest in orchards. Vector status in appearance and spread of ESFY in apricot, plum and peach orchards are presented as well. The presence of ESFY is confirmed in apricot and plum orchards in 2003, representing the first recording of this agent in Serbia. The presence of phytoplasma is confirmed in peach orchards in 2005, and this is also the first recording on this fruit species in West Serbia. The harmfulness of phytoplasma is manifested in older apricot orchards by the decline of tree crown and yield decrease or by sporadic decline of whole tree. In younger orchards, 80% of dry trees are registered in the third year after planting. The spread of ESFY phytoplasma by grafting is confirmed by molecular method of detection and identification of phytoplasma. Based on a year long research in the vicinity of Čačak, the author concludes that Cacopsylla pruni is present in these agrometeorological conditions, and that apricot is the tree most sensitive to the presence of phytoplasma, followed by peach and plum. The presence of ESFY phytoplasma is confirmed by PCR detection in 4% of new imago, and this is the first recording of phytoplasma in the insect body and species are ranged as potential vectors of phytoplasma in Serbia. Oligophagous nutrition and high migratory rate result in presenting difficulties for researchers who investigate and monitor this species. The pest appearance in the production area is highly impacted by terrain profile and wind rose based on the long-term study. Having in mind the lack of local wheather stations net and vacuum pump for insect hatching, it is possible to predict the first appearance of plum psyllid in orchards of some district. All cited results indicate the need of seasonal monitoring of this pest in the production area, as a way of control of the appearance and spread of ESFY. This results presents a contribution to better understanding of this economically highly important insect species, which has been investigated in more details for the first time in this research.