Management strategies for rhyparida in southern Queensland : SRDC final report BSS236

Abstract

Larvae of rhyparida beetles bore into the bases of newly ratooning shoots, causing dead hearts. Very minor damage will kill 'surplus' shoots. More intense damage appears to set plant growth back and cause some yield loss. Prolonged attack will kill all shoots and kill the stool, leaving large gaps and necessitating replanting. No insecticide is registered for control of the pest and the efficacy of cultural controls is unknown.The project developed a better understanding of the phenology of Rhyparida nitida ? this species has a one-year life cycle with extended oviposition over summer, slow development of small larvae during autumn and winter, and more rapid development of larger larvae during spring. The extended oviposition means that each generation has individuals of widely varying ages.Extension of outcomes to stakeholders took place through grower discussion groups, on-farm participatory trials, and newsletters.