Author
René FH Sforza
rsforza@ars-ebcl.org
USDA
Montferrier-sur-Lez
Coauthors
Marie-Claude Bon, USDA-ARS-EBCL, Montferrier-sur-Lez, France
Patrick Moran, USDA-ARS, Albany, USA
Abstract
Stinkwort (Dittrichia graveolens) is an annual plant in the Inuleae (Asteraceae), native to southern Europe, North Africa, and western Asia as far as east as Pakistan. In the USA, it invades 84% of California counties mainly in grasslands away from roads, riparian floodplains and wetland edges imperilling scarce water resources. Foreign exploration in Cyprus, Crete and France in its native range have identified a noctuid moth, Condica viscosa (Freyer) (Lepidoptera: Noctuidae), which is genetically homogeneous with respect to barcoding across surveyed countries. A colony of C. viscosa was established from individuals collected in Cyprus and has been maintained for 8+ generations without diapause. Preliminary biological observations in controlled conditions have shown a larval cycle with 6 to 7 instars, and a complete life cycle from egg to adult in ca. three weeks. Each adult female may lay more than 50 eggs on foliage. Pupation occurs in leaf litter or other debris. A shortlist of 26 plant species, mostly from the Inuleae tribe, was established. In no-choice tests, only two non-target species (Inula helenium and Buphthalmum salicifolium) were used by C. viscosa through to the pupal stage. Based on this preliminary physiological host testing, C. viscosa appears to be oligophagous, but restricted to the Inuleae, making this a promising candidate in the stinkwort biocontrol project, as neither of the two non-target species is native to the USA.
keywords
stinkwort
Noctuidae
specificity
exploration
Highlights
First host range testing of a candidate against stinkwort
A noctuid moth, Condica viscosa, shows a high degree of specificty
Mass rearing Condica viscosa is easy