An improved soil insect rating for seedling sunflowers

Abstract

A complex of soil-dwelling insects damages sunflower (Helianthus annuus L.) and other seedlings in Queensland. This paper compares the relative damage potential of the black field earwig, Nala lividipes (Dufour) (Dermaptera:Labiduridae), and crickets Lepidogryllus spp. and Teleogryllus oceanicus (Le Guillou) (Orthoptera : Gryllidae) to sunflowers in laboratory feeding studies. The results were converted to injury equivalents based on documented damage caused by Pterohelaeus alternatus Pascoe (Coleoptera : Tenebrionidae). The injury equivalents were added to the existing multispecies soil insect rating model currently used for other soil-dwelling insect pest species of sunflowers. Populations of additional pest species can now be more accurately assessed for their damage potential before crop planting.