Rusty Solutions for a Prickly Problem

November 25, 2011 by Leave a Comment

The state of Queensland has got an alien thorny invader: Prickly acacia, or in scientific terms Acacia nilotica subspecies nilotica.

Prickly acacia - Kunjithapatham Dhileepan

Prickly acacia invasion, north Queensland, Australia, Photo: Kunjithapatham Dhileepan, DEEDI, Australia

Prickly acacia is a shrub or small tree which belongs to the plant family Leguminosae, subfamily Mimosoideae, a family which also accommodates the sensitive plant Mimosa pudica, well-known as a curiosity house plant. The prickly invader A. nilotica is native to Africa, the Middle East and the Indian subcontinent and was introduced from India into Australia in the late 1890s. Originally imported as an ornamental, A. nilotica ssp. indica was later widely used as a shade and fodder tree for sheep. But what was initially a valued addition to the Australian flora soon became a menace. When the grazing regime in Australia changed from predominantly sheep to cows and the country also experienced a number of successive wet years, the balance swung in the favour of prickly acacia. The thorny shrub spread quickly and has now invaded around six million hectares of arid and semi-arid land in the State of Queensland. Acacia nilotica ssp. indica is also present in the Northern Territory as well as in Western Australia. Due to its substantial impact on the environment as well as on the economy, particularly on the livestock industry, prickly acacia was initially declared a noxious weed in Queensland in 1957. Subsequently the plant has also been listed as a “Weed of National Significance” for the whole of Australia. And Australians have every reason to be worried, as the prickly invader has got the potential to spread throughout the arid regions of the whole of northern Australia.

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Alien Battlefield

August 5, 2011 by Leave a Comment

Recent articles in Science, the NY Times and Nature have suggested that we should embrace invasive species and the resultant “novel ecosystems” and that those that do battle with such species are verging on xenophobic. This is a common cycle in many fields and I’m told that a discussion thread is considered closed once a poster has been described as xeonophobic or worse, if so this discussion could be over before it even begins. Nevertheless, a group of scientists and practitioners wrote a response which can be found on the ISSG website. The issues are certainly complex. It is true that preserving pristine ecosystems is a lost goal and there are probably none in existence anymore, but to do nothing and indeed to try to argue that the new system is one worth accepting suggests that the authors have either given up in the face of too difficult a task, or have seen an opportunity to publish something controversial. There are certainly “profits” of doom to be had on both sides. In order to get your invasive management project funded it is necessary to take the public with you and when engaging with the media evocative negative language can appear in print. On the other side it is easier to stand out from fellow authors if you challenge an accepted paradigm. In the case of weeds, it is generally understood that monocultures of the new plant are less biodiverse but more productive than the flora they replace and depending on your priorities their arrival could be a good or a bad thing. If we accept that biodiversity is a priority there are few arguments to be had for introducing new invasive exotic species except for biocontrol where the excellent paper by Van Driesche and many co-authors shows the potential benefits. It is this tool that was notably overlooked in the discussions despite choosing the Galapagos as a case study where there are excellent targets for weed biocontrol yet no funding has materialised despite the vast sums spent on vertebrate eradications.

Lantana on the Galápagos - a major invasive for which all hope is not lost

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Filed under Biocontrol, Invasive species

3D modelling: Not just for Hollywood, now for invasive species

April 8, 2011 by Leave a Comment

An easily overlooked but vitally important component of invasive species management is accurate identification. Picture the scene: It’s Australia, it’s a Friday afternoon, a comprehensive fire ant management strategy has been drawn up, baits have been acquisitioned and an eager team of volunteers is ready to deal with this invasive foe and escape for the weekend. There are plenty of ants around… but nobody knows if they’ve found the right ones because the pesky little critters all look so similar! Scientists in Australia believe they have a solution – a database of 3D images of known species against which 2D photographs of organisms taken and uploaded in the field are compared, giving an estimate of their likely invasive or native status.

Fire Ant - Leo Blanchette

3D Fire Ant – by Leo Blanchette, flickr

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Filed under Animal Science, Biocontrol Tagged with , ,

The Nagoya protocol and biological control by Matthew Cock

March 28, 2011 by Leave a Comment

Since 2009, I have worked with the Global Commission on Biological Control and Access & Benefit Sharing of the International Organisation for Biological Control to raise awareness of the issues relating to biological control which may be affected under the Convention on Biological Diversity’s access and benefit sharing protocol which was finally agreed at COP10 in Nagoya, Japan, in October last year1.

The IOBC Commission attended various background meetings, produced a report for the Global Commission on Genetic Resources for Food and Agriculture2, followed by a Forum Paper in the journal BioControl3 and various news items culminating in a World View page in Nature4 the month before the Nagoya meeting. Basically, we put the case that biological control is a public good, that countries that supply biological control agents are also importers of biological control agents, that the best way forward would be to continue the 100+ years history of free multi-lateral exchange of biological control agents between countries as non-commercial research under any future access and benefit sharing protocol, and that benefit-sharing should be based on shared research activities.

Matthew Cock - Nature

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Branson pickle

March 11, 2011 by Leave a Comment

Sir Richard Branson, the billionaire entrepreneur, is reported to have applied for permits to introduce a colony of endangered lemurs to his British Virgin Islands (BVI), Mosquito and Necker. Having “rescued” the island of Mosquito from purchase by a hotel chain in 2007, his intention was to turn his £10 million Caribbean tax haven into an ecological showcase, a luxury hideaway for the mega rich, with plans for Balinese-style, carbon neutral villas whilst “cultivating and supporting the biodiversity, then introducing habitats (such as rainforests) for people who will live in symbiotic form”.

The fanciful whimsy of the rich and famous is nothing new, however this controversial proposal has hit the headlines in BVI because it would appear that Branson has been granted import permits by the Natural Resources and Labour Minister, Hon. Omar Hodge, against the recommendations of technical groups in the Agriculture and Conservation sectors and in contravention of Territory laws. The decision is being contested by the Ninth district elections contender, Lorie Rymer and a petition is reported to be in circulation and will later be submitted to the Governor Boyd McClearly, who is appointed by the Queen and exercises executive authority on her behalf. Meanwhile, Minister Hodge is standing firm but has apparently alienated members of the community by stating on local radio that he “doesn’t have to answer to anyone because he is the Minister”.

(Ring-tailed lemurs by Woodlouse, Flickr Creative Commons)

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Filed under Animal Science, Environment, Uncategorized

Blowing our trumpet

February 3, 2011 by Leave a Comment

A well-balanced article about the biological control of Japanese knotweed was published today in a British newspaper. Most articles about the release of the Japanese knotweed psyllid (Aphalara itadori, pictured) that appeared last year were either dismissive of the idea of releasing a non-native insect to combat another non-native species, often on the grounds that the selected agents will also damage native species. Or the articles just copied bits of press statements.

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Wild gingers – beastly beauties

February 1, 2011 by Leave a Comment

Wild gingers, Hedychium spp., belong to the same family as edible ginger (Zingiber officinale), but they have no culinary value. Native to moist tropical forests of Central and Southeastern Asia, they are cultivated the world over as ornamentals. Their large, glossy leaves flare out around their tall reedy stems and their orchid-like, showy blossoms come in a breathtaking array of colours, exuding a heady perfume.  Such is their aesthetic appeal, that they are showcased in the finest Hawaiian leis (floral and leaf garlands). Their scientific name, Hedychium (pronounced “heh-DIK-ee-um”), is derived from the greek “hedys” meaning sweet and “chion” meaning snow and is based on the type species for the genus Hedychium coronarium (white ginger), the sweetly fragrant and best known ornamental ginger, which Cuba adopted as their official national flower in the 19th Century as a symbol of purity, rebelliousness and independence.

But in parts of its introduced range, such as Hawaii, New Zealand, Australia, South Africa, La Réunion and the Macaronesian Archipelagos, beauty has turned to beast; the very characteristics which gained them favour in gardens, such as hardiness and capacity for rapid, vegetative growth, have allowed them to naturalise in the wild and smother many unique and specialised communities, threatening delicate ecosystems, especially forest ground flora and associated fauna.  In particular, Kahili ginger, Hedychium gardnerianum has earned a place as one of the world’s 100 worst invasive alien species and biological control is considered the only practical and sustainable approach for the long-term management of large infestations in native forests.

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Evolution of "Super-Invasive" Cane Toads

December 20, 2010 by Leave a Comment

The cane toad (Bufo marinus) has become invasive in much of its introduced range, impacting significantly on biodiversity in these regions. Not only does the cane toad prey upon and compete with native species, it also produces a potent toxin that can be deadly to would-be predators. Nowhere is the impact of the cane toad more apparent than in Australia and a recent study indicates that edge-of-range populations there are evolving to become even better invaders.

Cane Toad
Cane toads in Australia (image courtesy of WAtoday.com.au)

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The economic impact of invasive species on Great Britain revealed

December 15, 2010 by Leave a Comment

A report, written by CABI for the Scottish government, Defra and the Welsh Assembly Government, estimates the cost of invasive non-native species to Great Britain in unprecedented detail. Invasive non-native species can have wide-ranging effects on biodiversity, crop production and people’s livelihoods. A better understanding of the negative impacts of invasive species will help to make people aware of invasive non-native species, to prevent new introductions and to deal with the problems caused by established invasive species.

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Filed under Environment, Uncategorized

Biological control of Mikania micrantha: Have we found the silver bullet?

December 7, 2010 by Leave a Comment

Mikania micrantha (mile-a-minute weed or South American Climber) is a major invasive alien weed in many of the tropical moist forest regions of Asia.  This neotropical vine is able to smother plants in agricultural ecosystems, agroforestry and native habitats.  Conventional control methods of manual removal (slashing) or herbicide application, are expensive, ineffective, not sustainable, and can be environmentally damaging.  Classical biological control was considered the best option to manage this weed, and CABI was funded by DIFID (UK- Department for International Development) to implement this strategy in India.  The research culminated in the release of a coevolved, host specific, rust pathogen (Puccinia spegazzinii), from the South America native range of the weed, into Kerala and Assam.  This rust pathogen infects all aerial parts of the plant (leaf, petiole and stem), leading to cankering and whole plant death (see image below).

Puccinia spegazzinii Nov 10

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Filed under Biocontrol, Plant Science

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