Importation, rearing and field release of the Cape Broom Psyllid

Citation

Land & Water Australia. 2008. Importation, rearing and field release of the Cape Broom Psyllid. [Online] (Updated July 31st, 2009)
Available at: http://lwa.gov.au/node/2574 [Accessed Wednesday 29th of February 2012 10:20:53 PM ].

Summary

This work identified the Cape broom psyllid as a potential biological control agent and studied its biology to develop testing protocols. The psyllid is abundant on Cape broom in the western Mediterranean, has several generations per year and can cause high levels of reduction in leaf area and reduced flowering (Sheppard 2000).

Host-specificity testing was completed via Weeds CRC1 funding for a list approved by Biosecurity Australia in 2002. However, a South Australian working group identified a need for further testing on additional Lupinus species.

This project, led by the South Australian Research & Development Institute (SARDI), in collaboration with CSIRO Entomology and other partner organisations, sought to complete host-testing on lupin species at the CSIRO laboratories in Montpellier, France, and finalise the approval process for the release of the psyllid and establish field releases in South Australia and Tasmania.

Aims

This project originally aimed to facilitate the importation and rearing of the Cape broom psyllid, Arytinnis hakani Loginova, followed by the field release of insects. However, during the course of the program A. hakani was discovered in the Mount Lofty Ranges. As a result of this discovery, the program was delayed until the Office of the Chief Plant Protection Officer (OCPPO) decided upon the most appropriate direction.

Because A. hakani was well-established at many locations in the Mount Lofty Ranges, no eradication plan was implemented. Since the discovery of A. hakani in the Mount Lofty Ranges the project aims changed from the importation and lab-rearing of A. hakani toward assessing the potential risks posed by A. hakani to lupins and horticultural brooms, using the established field population, and assessing the impact of A. hakani on Australian stands of Cape broom. As such, the revised research objectives are outlined below:

Complete host-testing on Lupinus spp. via CSIRO laboratories in Montpellier, France,
Seek a release permit for the Cape broom psyllid, A. hakani, from the Australian Government,
Assess potential field risk of A. hakani to selected lupins and horticultural brooms,
Determine the current distribution of A. hakani,
Assess the field impact of A. hakani in established G. monspessulana populations, and
Trial field releases of A. hakani at designated nursery sites.

Outcomes

It can be concluded that A. hakani has a narrow host range restricted to the tribe Genisteae, as evidenced by host specificity testing. Out of the commercially significant species within this tribe, Chamaecytisus prolifera (tagasaste), L. luteus and L. albus were oviposited on, receiving some eggs but none supported complete nymphal development and the commercially dominant L. angustifolius (narrow leaf lupin) consistently resulted in no oviposition. The later work conducted on Australian grown lupin species found that A. hakani posed a potential low level risk to L. cosentinii, L. atlanticus x L. cosentinii and a moderate risk to L. pilosus.

Arytinnis hakani is considered an agent worth redistributing to other states of Australia as a biological control agent for Cape broom. The benefits to these communities and the forestry industry of Cape broom biological control are substantial, and outweigh the low to moderate risk to non-commercial and weedy lupin varieties. Native Australian flora is not at risk of attack from A. hakani.

Background

Cape broom (or Montpellier broom), Genista monspessulana, is a woody legume weed with significant current and potential impacts on forestry production, biodiversity of natural ecosystems, grazing systems, access to amenity areas and fire risk. Infestations occur in all temperate states of Australia, with particularly severe infestations in the Adelaide Hills, southern Tasmania, central and southern Great Dividing Range of NSW and central Victoria. It is also becoming more prevalent in south-west Western Australia. Cape broom ranked 37th in the weeds nominated for WoNS (Thorpe and Lynch 2000), with a particularly high impacts score due to its formation of dense, impenetrable thickets arising from a long-lived soil seedbank.

CSIRO and CRC Weed Management Systems (Weeds CRC1) commenced investigations into biocontrol of Cape broom in 1999-2000, with additional investment from the State of California, as part of the International Broom Initiative (http://www.cal-ipc.org/ip/research/biocontrols/broom/index.php).