Höhn, H., Höpli, H.U., Lahusen, A., & Vetsch, W. 2004 Astprobenuntersuchungen 2003/2004: zeigt der warme Sommer Auswirkungen bei Insekten und Milben? [Apple branch testing in 2003/04: did the warm summer influence insects and mites?].. Obst- und Weinbau 140(5): 6-10.

Notes: A total of 344 samples were collected in the winter of 2004 from 110 apple orchards in the German part of Switzerland. Per orchard, about three samples (three cultivars) were taken from 2 m long sections of 2-3 year old fruit-bearing branches (10 x 20 cm thick). The survey has been carried out over the last 50 years, however results are shown only for the last five years. Parthenolecanium corni reached record levels with 15.6 larvae/sample, only seen in the early 1950s. High numbers were also found of Lepidosaphes ulmi, Panonychus ulmi, Typhlodromus pyri and Operophtera brumata. The 2-3 fold increase in P. ulmi was mainly caused by the dry and warm summer. However, the average count of 620 winter eggs remained still below the damage threshold of 1200 eggs/2 m branch. Low numbers were found of Quadraspidiotus [Diaspidiotus] sp., Rhopalosiphum insertum, Dysaphis sp., Eriosoma lanigerum, Cacopsylla mali and Rhopobota naevana.