Seasonal occurrence of vine pests in commercially treated vineyards in the Hex River Valley in the Western Cape Province, South Africa
The population fluctuations of arthropods attacking table grapes were studied in 12 commercially treated vineyards in the Hex River Valley in South Africa for three years. Sampling was conducted by inspecting different plant parts and using a variety of traps. Planococcus ficus (Signoret) males in the pheromone traps started increasing during December, to reach a peak at the end of February. Cordon infestation preceded bunch infestation by three to five months, the latter occurring from about January or February. Thrips, mainly Frankliniella occidentalis (Pergande), caught on blue sticky traps were active during spring and early summer. Damage to the berries occurred about four weeks after thrips were recorded on the sticky traps. Phlyctinus callosus Boh. was recorded under fluted cardboard bands tied around the stems of vines from early October, with the first bunch damage recorded towards the end of October. More Epichoristodes acerbella (Walker) moths were caught in pheromone traps during the cool winter months than during the hotter summer months. Damage to the bunches started during November and declined during January and February, only to increase again towards the end of February and March. Although Helicoverpa armigera (Hübner) moths were caught in pheromone traps, no damage ascribed to this insect was recorded. The only phytophagous mite was Tetranychus urticae Koch, which was active throughout the fruiting season. The most common predatory mite was Euseius addoensis (Van der Merwe & Reyke).