Tree Injection in the Management of Horse-Chestnut Leaf Miner. Cameraria ohridella (Lepidoptera: Gracillariidae)

Insect and disease problems often occur suddenly, and frequently represent a crisis that demands immediate attention. There are some problems with tree health care because application of sprays to shade trees in urban areas requires specialized, expensive equipment. Microinjection is a type of trunk injection where small amounts of therapeutic chemicals are introduced directly into a tree without any contact with the environment. We applied microinjection technology by using VIVID^®II (Tree Tech Microinjection Systems, Morriston, FL, USA) insecticide to solve the problem with horse-chestnut leaf miner (Cameraria ohridella Deschka et Dimic) on horse chestnut tree (Aesculus hippocastanum L.) in urban greenery in Slovakia. In 2006 were treated 230 host trees in 12 localities, 337 trees in 15 localities were treated in 2007. Mean efficiency of control measures was above 95%. The presence of insecticide residues were analyzed in pollen. 0.145 mg/kg of residues was detected in pollen one day after treatment. It decreased rapidly 8 days after treatment and 16 days after treatment was not detectable. In spite of these results the treatment after blossom is recommended.