Phenology ofOosomus varius(Curculionidae) andPrasoidea sericea(Chrysomelidae) onPinus radiatain the South-western Cape Province

Abstract

SYNOPSIS Oosomus varius and Prasoidea sericea adults feed on the needles of Pinus radiata planted within or adjacent to fynbos vegetation in the south-western Cape Province. Activity peaks were determined by counting, at weekly intervals, the number of beetles present on 10 young pine trees. The O. varius activity peak occurred in August where 42% of all beetles were active, with 87% of the beetles present in July, August and September. P. sericea also had their activity peak in August when 60 % of all beetles were active, but with August and September alone accounting for 87 % of all beetles. The occurrence of the activity peaks was consistent each year over the five-year study period. This information facilitates the correct timing of prophylactic insecticide sprays.