New pest of cucumber reported from Switzerland
A new pest of cucumber has been reported from the western part of Switzerland. In 1992, one establishment in the canton of GenŠve growing cucumbers was heavily attacked by Tyrophagus neiswanderi, a mite which has not been previously reported to attack cucumbers in Europe. The mite had been found, with hardly any significance, on ornamentals. The heavy infestation of the establishment in Switzerland was attributed to the growing medium which consisted of 60% wood chips, which seemed to have introduced the pest into the glasshouses. The mite attacks only the leaves of the cucumbers, feeding on the parenchymatic cells and perforating the leaves with a multitude of small (max. 5 mm) holes. Symptoms on fruits and flowers were not observed.
Sources
Fischer, S. (1993) Observation d'un nouveau ravageur du concombre en Suisse occidentale, Tyrophagus neiswanderi Johnston & Bruce (Acari; Acaridae).
Revue Suisse de Viticulture Arboriculture Horticulture 25, 103-104.