Phenology of the New Zealand flower thrips (<i>Thrips obscuratus</i>) in two vineyards

Abstract

Adult thrips especially New Zealand flower thrips (Thrips obscuratus) were monitored with white water traps at Canterbury House Vineyard near Waipara in North Canterbury and Neudorf Vineyard near Motueka from spring to autumn in the 2003/04 and 2004/05 seasons Traps were placed within the grapevine rows 140 cm above ground The largest populations of airborne thrips of which around 90 were T obscuratus occurred during the five weeks coinciding with grapevine flowering In 2003/04 additional traps were placed at 80 and 15 cm above ground but only at Canterbury House Vineyard and T obscuratus were more abundant in the highest traps than in the lower ones Sampling of flower bunches revealed that T obscuratus were more abundant in the later flowering Sauvignon blanc than Riesling grapevines Overall more thrips were trapped in Neudorf than Canterbury House vineyard which may be attributed to the greater diversity of flowering sources outside the vineyards