San Jose scale (Comstockaspis perniciosa) – new findings of monitoring and possibilities of organic control

Abstract

San Jose scale (Diaspidiotus perniciosus) is a widespread pest in the Czech Republic and its harmfulness has increased over the last years. The European Union removed this pest from the list of quarantine pests because of its spread to almost all European countries. The scale develops on vegetative organs, blossoms and fruits. It most commonly occurs on the bark of trunks and branches. Due to the sucking of the plant sap, the trees may die. The only stage that is sensitive to treatment is the crawler stage. Possible control methods are limited to applications of oil-based preparations in early spring in organic agriculture. Our research is two-fold. Firstly, we are testing different pheromone traps (wing traps, delta traps, open traps) suitable for the monitoring of the occurrence of San Jose scale males in three different orchards. The wing trap catches the most males but the delta trap is the most well-adapted for user handling. The second area of our research is the testing of different preparations suitable for organic agriculture against San Jose scale nymphs. In 2013, the highest efficacy was achieved with the Naturalis (Beauveria bassiana) preparation: 59.6-60.9%. Quite good efficacy was recorded with the RockEffect (Pongamia pinnata oil) preparation: 41.8-56.9%. In 2014, the highest efficacy was achieved with the Naturalis preparation: up to 85.2%.