Testing the specificity of the French broom psyllid (Arytinnis hakani) on native California lupines

The exotic invasive French broom, Genista monspessulana (Fabaceae), is a woody legume of major concern in the Western U.S. and other countries, including Australia, Chile, New Zealand, and South Africa. It displaces native flora and desirable forage species by forming dense monotypic stands, threatens arthropod diversity, is toxic to cattle, and increases the intensity and frequency of fires. 

The present study renews a biocontrol programme with the French broom psyllid Arytinnis hakani (Hem., Psyllidae) conducted by Sheppard et al. (2006). As French broom is closely genetically related to lupines, some of which are endemic to California, we concentrated our efforts on conducting host specificity evaluation on lupines with choice and no-choice tests. Since 2010, foreign exploration in western Europe, including France, Corsica island, Central and Southern Italy and Sardinia resulted in collections of a minimum of three phytophagous insects: Lepidapion near argentatum (Col., Apionidae), Uresiphita polygonalis (Lep., Crambidae), and Arytinnis hakani. The latter was collected in Southern France in March 2012. We started no-choice tests with Lupinus arboreus, L. texensis, L. longifolius, L. formosus, L. perennis, and in choice tests, only L. longifolius, L. formosus, L. microcarpus and Genista monspessulana as control in both tests. Results showed that firstly L. longifolius, L. arboreus, L. formosus and secondly L. longifolius, L. formosus can support feeding and full development of A. hakani both in controlled and open field conditions respectively. Additional data on psyllids flight and risk assessment will be presented and discussed.