Development of a pest management system for table grapes in the Hex River Valley

A study was performed to develop a generic pest monitoring system for sampling the main table grape pests in vineyards in the Hex River Valley, Western Cape Province of South Africa.The presence of phytophagous and predatory mites on cover crop plants was also investigated as this may contribute to biological control of the phytophagous mites in vines.Life table studies for Epichoristodes acerbella (Walker), an important phytosanitary pest, were conducted to determine whether or not this pest was sensitive to high temperatures.Information gained from the latter can also be used for breeding purposes in the possible future development of a sterile insect technique (SIT) programme to control this pest.The sampling system consisted of inspecting 20 plots of five vines per plot per one to two hectares.The top fork of each of the five vines per plot was examined for Planococcus ficus (Signoret) to a distance of within 30 cm of the stem, as well as the distal 15 cm of one cane per vine for the presence of P. ficus and damage caused by Phlyctinus callosus Boh.One bunch per vine was examined for insect damage or presence, and one leaf per vine for the presence of leaf infesting arthropods, such as Tetranychus urticae Koch, P. ficus and Frankliniella occidentalis (Pergande).Corrugated cardboard bands, tied around the stem of one vine per plot, were used to monitor activity of P. callosus.Blue sticky traps, at a density of four to five traps per one to two hectares, were used to monitor activity of F. occidentalis.Pheromone traps, at a density of one trap per one to two hectares, were used to monitor activity of P. ficus, E. acerbella and Helicoverpa armigera (Hübner).All the above-mentioned inspections were done at two-weekly intervals, except traps for E. acerbella and H. armigera, which were inspected weekly.In each of the rows in which the sample plots were situated, one leaf of each of the cover crop plant species was examined for the presence of phytophagous mites and their predators.The abundance and distribution of cover crop plants were determined using a co-ordinate sampling system.Cover crop sampling was done at monthly intervals.The current threshold for P. ficus is 2% stem infestation, which is reached when more than 65 males per pheromone trap are recorded.Counting mealybugs on the sticky pads in the pheromone traps is time consuming.However, the number of grid blocks on the sticky pad with males present can be counted.When P. ficus males are found UITTREKSEL 'n Studie is uitgevoer om 'n generiese moniteringstelsel te ontwikkel om die vernaamste plae van tafeldruiwe in die Hexrivier Vallei, Wes-Kaapprovinsie van Suid-Afrika te monitor.Die teenwoordigheid van plantvoedende en predatoriese myte op dekgewasplante is ook ondersoek aangesien dit kan bydra tot biologiese beheer van plantvoedende myte in wingerde.Lewenstabelstudies is vir Epichoristodes acerbella (Walker), 'n belangrike fitosanitêre plaag, gedoen om te bepaal of hierdie plaag sensitief vir hoë temperature is.Inligting wat vanuit laasgenoemde verkry is, kan ook gebruik word vir teëldoeleindes in die moontlike toekomstige ontwikkeling van 'n steriele insek tegniek (SIT) program om hierdie plaag te beheer.Die moniteringstelsel het uit die inspeksie van 20 plotte van vyf wingerdstokke per plot per een tot twee hektaar bestaan.Die boonste vurk van elk van die vyf stokke is vir Planococcus ficus (Signoret) tot 'n afstand van 30 cm vanaf die stam deursoek, asook die distale 15 cm van een loot per stok vir die aanwesigheid van P. ficus en skade veroorsaak deur Phlyctinus callosus Boh.Een tros per stok is vir insekskade of -aanwesigheid deursoek en een blaar per stok vir die aanwesigheid van arthropode op blare, soos Tetranychus urticae Koch, P. ficus en Frankliniella occidentalis