Implementation of some biopesticides in integrated pest management (IPM) of larch aphid Adelges laricis Vallot (F. Adelgidae – Homoptera) and the horse chestnut leaf miner Cameraria ohridella Desch & Dimic (F. Gracillariidae – Lepidoptera)

Abstract

The larch wooly adelgid Adelges laricis is an important pest due to his attacks, especially against the nurseries and young trees and the horse chestnut leaf miner Cameraria ohridella which attacks the leaves of the Aesculus hippocastanum L., that produces trees defoliation, there growth slowing down and finally there drying.In the management of the larch wooly adelgid, in the lab tests, the microbial products Laser 240 SC and Milbeknock and the vegetal one NeemAzal T/S, had a high efficacy against the young larvae of Adelges laricis (98-100%) and more reduced against the older larvae (60-98%). The product Laser 240 SC, that acts more by ingestion as by contact, has lesser efficacies against older larvae. In the experiments on trees all bio pesticides had high efficacies. It is recommended the application of the treatments at the beginning of the infestation when the young larvae appear. In the management of the chestnut tree leaf miner Cameraria ohridella the use of Laser 240 SC and NeemAzal T/S by spraying, the leaves attack was between 20-30%, comparatively with 80% for the untreated witness. Because they are 3-4 generations/year, the treatments must be fulfilled in the eggs laying periods and during the neonate larvae apparition, in order to obtain high efficacies. The treatments by painting with NeemAzal T/S reduce the mining larvae number and also the attack’s degree on the leaves. After 35 days from the treatment its take place a rising of the attack due to the pressure of the next generation therefore another treatment is necessary. The treatment on the bark is recommended for the residential areas and parks because the spraying treatments are harmful for the mean’s health.