PROPARGITE RESISTANCE IN TWO-SPOTTED SPIDER MITE (TETRANYCHUS URTICAE KOCH) ON CZECH HOPS

J. Vostrel
Two-spotted spider mite (Tetranychus urticae Koch) along with damson hop aphid (Phorodon humuli Schrank) are the key pests of hops in the Czech Republic. Tetranychus urticae can seriously damage hop plants especially in warm dry weather. Under such conditions, control becomes very difficult. Contemporary hop protection against T. urticae is based on application of miticides such as propargite. Because this compound has been used in the Czech Republic for mite control for more than two decades, resistance of field strains of two-spotted spider mite may be expected. To investigate this phenomenon, samples of field populations were taken and subjected to laboratory tests in a Potter spray tower. Values of LC 50 in these strains were compared with a susceptible strain to determine resistance factors (RF). The data surprisingly showed quite low values of RF and a good biological efficiency. Therefore, propargite can be still recommended to control T. urticae within hop yards in the Czech Republic.
Vostrel, J. (2009). PROPARGITE RESISTANCE IN TWO-SPOTTED SPIDER MITE (TETRANYCHUS URTICAE KOCH) ON CZECH HOPS. Acta Hortic. 848, 165-170
DOI: 10.17660/ActaHortic.2009.848.18
https://doi.org/10.17660/ActaHortic.2009.848.18
two-spotted spider mite, propargite, miticides, hop protection, resistance factors, LD 50, strains
English

Acta Horticulturae