Biocontrol introduction
Target pest: Asparagus asparagoides (Asparagales: Asparagaceae), bridal creeper, smilax
Agent introduced: Puccinia myrsiphylli (Pucciniales: Pucciniaceae), bridal creeper rust
Import notes:
Waipara et al. (2006) - in November 2005, diseased A. asparagoides plants infesting barberry (Berberis glaucocarpa) and boxthorn (Lycium ferocissimum) hedgerows were observed on farmland near the International Airport at Mangere, Auckland. A severe disease outbreak was underway with most plants exhibiting typical infection symptoms of yellow leaf spots on newly infected leaves through to complete dieback and defoliation of plants. Rust pustules associated with the infection were identified as Puccinia myrsiphylli, the first record of this fungus in New Zealand. It had been released as a biocontrol agent for A. asparagoides in Australia in June 2000. It is concluded to have been introduced into New Zealand either accidentally or autonomously by way of wind-dispersed spores.
Release details:
Waipara et al. (2006) - self-introduced, first detected in 2005 [see Waipara et al. (23006) entry in 'Import notes' section].
Establishment:
Harman et al. (2008) - Asparagus asparagoides was surveyed at 32 sites throughout its range in New Zealand between November 2005 and January 2007. Puccinia myrsiphylli was recorded at 15 sites across most of the weed’s North Island distribution (Northland to Wairarapa) but was absent from the East Coast (North Island) and the South Island.
Landcare Research (2014c) - widespread.
Impacts on target:
Harman et al. (2008) - a 2005-07 survey [see Harman et al. (2008) entry in ‘Establishment’ section] found A. asparagoides attacked by P. myrsiphylli over its two active growing seasons (winter-spring, autumn). Damage was often severe, causing up to 100% premature defoliation of the plant prior to both fruit ripening and natural senescence. Furthermore, there was evidence that the rust may cause a synergistic disease complex with another widespread primary pathogen on A. asparagoides, Colletotrichum gloeosporioides, which, by itself, caused minimal damage to the plant. Puccinia myrsiphylli appears to be an effective biocontrol agent for A. asparagoides in New Zealand.
Landcare Research (2014c) - causing severe damage at many sites.
Landcare Research (2016i) - widespread and providing good control.
Impacts on non-targets:
Waipara et al. (2009) - to assess non-target impacts of pathogenic weed biocontrol agents, including Puccinia myrsiphylli, introduced to New Zealand, nationwide surveys were conducted 2000-2009, focussing on plants closely related to the target weeds. No non-target damage was observed for P. myrsiphylli, despite positive infection being observed on many of the host (target) plants at the same sites.
References
Harman HM, Waipara NW, Winks CJ, Smith LA, Peterson PG, Wilkie JP (2008). Natural enemies of bridal creeper, Asparagus asparagoides, in New Zealand. New Zealand Plant Protection 61: 362-367 https://journal.nzpps.org/index.php/nzpp/article/view/6884/6712
Landcare Research (2014c). Who's who in biocontrol of weeds? What's new in biological control of weeds? 69: 10-11 https://www.landcareresearch.co.nz/assets/Publications/Weed-biocontrol/WhatsNew69.pdf
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
Waipara NW, Barton J, Smith LA, Harman HM, Winks CJ, Massey B, Wilkie JP, Gianotti AF, Cripps MG (2009). Safety in New Zealand weed biocontrol: a nationwide pathogen survey for impacts on non-target plants. New Zealand Plant Protection 62: 41-49
Waipara NW, McKenzie EHC, Harman HM, Winks CJ, Park D (2006). First record of bridal creeper rust, Puccinia myrsiphylli, a classical biocontrol agent of the environmental weed bridal creeper, Asparagus asparagoides, in New Zealand. Australasian Plant Disease Notes 1: 23-24 https://doi.org/10.1071/DN06010
