Published in Scientific Papers. Series B, Horticulture, Volume LVIII
Written by Margit PÁL, János BÁLINT, Adalbert BALOG
Described for first in 1986 near Ohrid lake from Macedonia, by Deschka & Dimie, the horse chestnuts leaf miner (Cameraria ohridella) a highly invasive moth, in just two decades has spread all over the continent, and caused considerable damages in horse chestnuts populations across Europe. In Romania has been described in1993. In our climatic conditions develops 3-4 generations per year. Adult moths are transported by wind, anthropogenic transport by vehicles in infested leaf fragments or infested nursery stocks. The most important damage is esthetical, because of fallen foliage but also ecological do to the effect of the reduced active surface of photosynthesis, and progressive decline of trees. Also causes economic losses due to the costs of protect or heal the affected trees. As a consequence different techniques have been adopted in the recent years to control the moth like collection and destruction of fallen leaves where the pupae over-winter or spray of systemic insecticides. They native natural enemies are insufficiently adapted and not able to regulate the leaf miner’s population density, even after two decades of moth infestation typical parasitism rates are merely around 0–10%.The chemical control is difficult especially through the application of insecticides; the aerial spraying to treat trees in urban areas requires specialized expensive equipment. Moreover the systemic insecticides may cause side effects on non-target species. The endoterapy technique by introducing pesticides directly inside the trees can be the best solution. Microinjection is a type of trunk injection where small amounts of therapeutic chemicals are introduced directly into the trees body without any contact with the environment. During our experiment a total number of 84 chestnut threes where identified from which 38 were treated with two different active chemical agents: abamectin and imidacloprid. Treatment applications were made in May 2011. A plot of 46 threes where used as control without treatment. The analysis of the collected results shows, that the treated trees of up to 90% are protected with endoterapy against horse chestnuts leaf miner (Cameraria ohridella).
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