Target pest: Clematis vitalba (Ranunculales: Ranunculaceae), old manís beard
Agent introduced: Monophadnus spinolae (Hymenoptera: Tenthredinidae), old man's beard sawfly
Imported: 1997, 1998, 1999
Import source: Austria, 1997; Switzerland, 1998, 1999
Release details: Gourlay (2007) - released widely (details unknown) from 1998, but at limited number of sites as difficult to rear. Landcare Research (2016d) - 16 releases were made at 14 sites from Bay of Plenty to Otago, by far the largest being nearly 3,000 individuals at a site near Nelson in 2002. Landcare Research (2018g) - the sawfly, sourced from Serbia, will be re-released, in much bigger numbers and with better genetic diversity, at a site carefully chosen to be as be safe as possible from disturbance. The sawfly population in Serbia may also have a better climate match with New Zealand than earlier introductions.
Establishment: Gourlay (2007) - no signs of establishment recorded. Landcare Research (2014c) - probably failed to establish. Landcare Research (2016d) - surviving release sites checked; found only at Nelson site and rare even there (3 larvae, 1 adult found). Population may be inbred, and predatory vespid wasps are likely to be a limiting factor in New Zealand. Landcare Research (2017g) - only established in low numbers at one site in Nelson. More material will be imported in 2017 in an attempt to establish this insect more widely.
Impacts on target: Landcare Research (2016i) - has only established at one site in Nelson where it still appears to be rare and having no obvious impact.
General comments: Landcare Research (2016d) - merits of attempting to establish the sawfly again considered. Initial step was to check release sites once more (see details under "Establishment"). Recommended against further releases as vespid wasps likely to be limiting factor in New Zealand. Landcare Research (2018g) - further releases will be made (see details under "Release details"), with steps taken to ensure that wasps donít impact on the newly released sawflies, although it is thought this is not a key reason for the poor establishment previously, since the larvae readily ooze haemolymph when threatened, which deters predators.
Gourlay H (2007). Old Man's Beard Saw Fly. In The Biological Control of Weeds Book (Landcare Research) http://www.landcareresearch.co.nz/research/biocons/weeds/book/documents/Old_Mans_Beard_Sawfly.pdf
Landcare Research (2007). New Zealand Arthropod Collection (NZAC) Biological Control Voucher Collection. http://www.landcareresearch.co.nz/resources/collections/nzac/holdings/biological-control-voucher-collection
Landcare Research (2014c). Who's who in biocontrol of weeds? What's new in biological control of weeds? 69: 10-11 http://www.landcareresearch.co.nz/publications/newsletters/biological-control-of-weeds/issue-69
Landcare Research (2016d). What's happening with old man's beard? Weed Biocontrol: What's New? 76: 4-5 http://www.landcareresearch.co.nz/publications/newsletters/biological-control-of-weeds/issue-76
Landcare Research (2016i). Who's who in biological control of weeds? Weed Biocontrol: What's New? 77: 10-11 http://www.landcareresearch.co.nz/publications/newsletters/biological-control-of-weeds/issue-77
Landcare Research (2017g). Who's who in biological control of weeds? Weed Biocontrol: What's New? 81: 10-11
Landcare Research (2018g). Old man's beard to face new attack. Weed Biocontrol: What's New? 84, May 2018