Presentation on theme: "Biological control for weeds in Ireland with reference to JK & HB"— Presentation transcript:
1Biological control for weeds in Ireland with reference to JK & HB Dick Shaw & Rob Tanner- CABI
2Format Brief introduction to CABI and invasives Biocontrol – types, history and examplesAzolla weevilJapanese knotweed: and the psyllidHimalayan BalsamFloating Pennywort
3What/who is CABI?Formerly the Commonwealth Agriculture Bureaux International, Origins back to 1910.UN-Treaty level, not-for profit intergovernmental organisation owned by its 45 member countriesCABI includes the former International Institute of Biological Control (IIBC) and 3 other institutes
4Our member countries and centres CABI centreCABI member country
5KNOWLEDGE FOR LIFE Our mission CABI improves people’s lives worldwide by providing information and applying scientific expertise to solve problems in agriculture and the environmentKNOWLEDGE FOR LIFE
6CABI Publishing Abstracts – environment, agriculture, tourism 7 million abstracts (10,000 free text added/yr)Books - 60 new titles/yearInvasive Species Compendium >1,000 species included so far (hopefully open access if final funding can be found)£20 million turnoverOnly 5% of our income is from member contributions (“core funding”)
7CONTROL IAS CBD Commitments PREVENT, ERADICATE or What about the really big problems we already have?
123 Categories of Biological Control Conservation - Protection and maintenance of existing Natural Enemies (NEs)Inundative - a.k.a the “Mycoherbicide Approach” using native pathogens for repeated applicationClassical - Using Co-evolved (highly specific) NEs from the area of origin of the plant to provide self-sustaining control after a single release.There are three types of natural control or as the scientific literature would have it “Biological Control”I will mostly be talking about Classical.But let’s get the concept of a natural solution clear
13Rhododendron ponticum Can’t use the classical approach since there are 500 cultivars.
19Prickly pear in Australia 50 million hectares of it in New South WalesEarly last century the prickly pear covered 50 million acres which is about 30 times the size of Devon or most of the UK. Hard to conceive but it does show why countries like OZ, NZ and the US lead the way in natural control
2050 million acres cleared and now exists in harmony with surrounding vegetation. Silver bullet This resulted in about 250,000 square kilometres of agricultural land being cleared of prickly pear.By the mid 1930’s Prickly pear was no longer a problem.A Cactoblastis memorial hall was built to honour this successful mothBefore
23Rubber vine weed 60,000 hectares of Queensland infested Green custard bringing down intact Eucalypt forest and threatening national parksbut not the case in madagascar where the plant is from
24Maravellia cryptostegia from Madagascar screened in our fcility and eventaully cleared fro release and now native species are returning and a previously-released insect has been redicovered after being presumed to have failed.Rare plant, rare rust but released from its natural enemies BOOMThe questiopn we are always asked is how safe is this
25Is It Safe? Over 1,000 releases of biocontrol agents around the world >350 agents against 133 target weedsA century of researchAny non-target effects are predictable by the vigorous safety testingAn International code of conduct8 examples of “non-target” effects (7 of which predicted or predictable with current approaches)This FAO code of conduct fits in with the CBD and promotes the free and fair exchange of biological control agents
26EU Activity Country Recipient Source Austria 48 Finland 5 France 111 48Finland5France111Germany46Greece29Italy71Portugal18Spain9Sweden3UK41Total381
32Symptoms of the Fungal Pathogen Phloeospora heraclei Giant Hogweed (Heracleum mantegazzianum)Parsnip (Pastinaca sativa)
33This is a typical shot of the unruly knotweed ignoring the rules of the road
34the bombs we can deal with” “The site is a challenge. We have identified unexploded wartime bombs and Japanese knotweed………..the bombs we can deal with”Head of London Development Agency on the subject of the 2012 Olympic siteThis is the kind of site where the costs can go through the roof. The worst case scenario is £46,000 for a 1m patch on a development site. The 2012 Olympic site has a 4 hectare infestation which has been reported to be costing 65 million to remove. Indeed the london Development Agency Representative is quoted as saying we have problems with unexploded wartime ordinance and Japanese knotweed……….the ordinance we can deal with.
35Japanese knotweed(s) Fallopia japonica var. japonica Bailey syn. Reynoutria japonica Houttuynsyn. Polygonum cuspidatum Siebold & Zucc.F. sachalinensis (Giant knotweed)F. x bohemica (hybrid)There I more than on ejapanese knotweed and certainly more than one name for each. It is fairly easy to distinguish the giant from the japonica variety but bohemica versus japonica is a little more tricky. The key is to look for hairs on the underside and the base of the largest leaf.Smooth and flat = japonicaHairy and heart shaped = sachalinensis (plus huge)Small hairs and intermediate leaf base = bohemicaIn the Uk we have one clone leading to one newspaper describing “the biggest female on earth set to destroy rural Britain”Incidentally JK has many common names and recently the Cornish have adopted the name Ladir tir translated from the democratically selected english descriptor Land thief.Courtesy of Japanese kntoweed manual Child & Wade
46Mycosphaerella polygoni-cuspidati The agent which still holds the most promise however is this leafspot. Highly damaging and ubiquitous found on Kyushu, Honshu and Shikoku islands, from sea level to altitudes of over 1,m. Coinciding with knotweed emergence in late April through to senescence in October/NovemberBased on 1918 published description in Japanese journal. Neotype needed. Thus, M. polygoni-cuspidati has all the characteristics of a hemibiotroph- a prolonged or well-developed, latent or colonization phase, followed by a necrotic phase, and even production of spermogonia within living tissues-and this life cycle is summarized in schematic formMycosphaerella polygoni-cuspidatiLeafspot fungus- so common that it is included in the Flora of Japan
47Life cycleMicrocyclic or reduced life cycle - only functional spores are spermatia and ascosporesPrimary source of infection is ascospores, no anamorph or macroconidial stage foundNo ascomata produced in vivo or in vitro despite varied humidity regimes+agar media trialsMycelial infection found to be comparable in lab40㎛The lifecycle is complicated. Categorical ID came over a year into the project when microscopic analysis of fruiting structures placed it firmly in the Mycosphaerella species concept. Very slow growing and previous attempts to identify causal agent revealed only faster growing endophytesBased on both field and experimental data, it is concluded that Mycosphaerella polygoni-cuspidati has a microcyclic or reduced life cycle in which the only functional spores are spermatia and ascospores. There is no evidence of a functional macroconidial stage or a true anamorph in the lifecycle Unlike M. brassicicola, however, ascomata have never been observed in inoculated plants (in vivo) or in culture (in vitro), despite testing various recommended humidity regimes and agar media (Snyder 1946), Nelson and Pound 1959), so it cannot be determined if the fungus is homo-or heterothallic. Indeed, in the field, ascomata are uncommon and most of the material collected over the 4-year period was dominated by the spermogonial stage. It could be argued that ascomata develop mainly after leaf fall but there was no evidence of this from a detailed examination of leaf litter collected prior to and during the winter months.
48Macro/microscopic analysis F. ConollyanaP. maritimumF.japonica60 plant spp tested (mainly mycelium)no symptoms on F. sachalinensis & F. compacta21 N. American species tested to some degree – still promisingAfter days on p. maritimum, guard cell reaction with bohemicaF x bohemica
56DISMISSED Ex F. japonica host Can rear through on P. hydropiper but produced very small offspring – too few to establish a culture.Only ever seen on Japanese knotweed in Japan even when populations were very high indeedEx P. hydropiper host
62Two agents have been selected the first, a Psyllid with high potential, small yet damaging in large numbers. HR studies initiated and looking promising-142,000 eggs followed, <1% laid on plants of concern and none developed.
64Aphalara informationEach female produces a mean of 637 eggs ± (±1SE, n = 11).The mean period of production is 37.5 days ± 5.85 days (±1SE, n = 11).Adults live up to 67 days
65Centrifugal phylogenetic method: More closely related species morelikely to be attacked than more distantly related onesFamilyTribeSubtribeGenusSpecies
66Test Plant List 90 species and varieties representatives from 19 families.All naïve Polygonaceae37 plants natives23 species introduced to the UK,3 species native to Europe,13 ornamental10 economically important UK species
67The 78 spp. that did not receive eggs are excluded Bar chart showing mean egg count on those plants that did receive eggs in multiple choice oviposition tests. (+/- 1SE). Development only successful to the left of red line
69Extent of nymph development on NT hosts which have received eggs Request for more information from CSL as part of review of PRAHand transferred nymphsHigher humidity than before6 reps x 10 N1 nymphs = 60 individualsIncreased survival on knotweedRisk of artificially increased survival on NTs
71Muehlenbeckia complexa “wire plant” “Garden thug” (Clement & Forster, 1994)Weed in AustraliaUS team have found same result for northern Ai strain with another congeneric
72Aphalara summary Still happy in culture in the UK 87 species / varieties used so far, 3 rare spp. to go145,172 eggs followed, 928 (0.64%) laid on non-targets but no developmentNymph transfer development studies and target-absent oviposition studies largely support findingsAdult no-choice starvation studies show very restricted range
84Interaction with herbicide = Significant increase in leaf loss Change in leaf number two weeks after spraying with sub-lethal dose of systemic herbicide following exposure to four levels of psyllid feeding
85Interaction with herbicide Reduction in leaf area
86Japan 2007 Primarily Giant knotweed in Hokkaido and N. Honshu Collections of northern species for NA screening
93What next?Wildlife & Countryside application complete for England (Devolved Authorities version in prep.)Pest Risk Analysis completeContingency and monitoring plan proposedExternal peer reviewers begunPublic consultation Web (3 months)Stakeholder awareness raising (during above)Ministerial decision (last quarter 09?)Release if authorised (April 2010)
95And when the plant forms monocultures similar to this one on the river torridge in north deveon, the seed production of the population can equate to a seed rain of seeds per m sqWhen hb grows in riparian systems seeds become incorporated into the water body carried down stream rivers throughout the uk have acted as major corridors for this species dispersalAlthough the Seed bank is relatively short lived 18monthsSynchronous germination large seed bank to achive sufficent biomass to supress performance of other species it has been shown H.balsamHB has been shown to outcompete some of our most vigerous growing native species
962007By the year 2000 hob occurs in over ½ of the 10km recording squaresConfidently say few rivers in the Uk which haven't been colonised by hob
97Native range balsam spans 2 countries Regional centre, aid travel, communication excellent ecologists and botanistsDecided to sample in august when the plant was in full bloom, aid identificationand this was the optimum time for plant pathogens why????Unfortuantly sampling in august was to the detriment of arthopod collections we didn’t collect anything like the number of species we would have hoped forAt the time of of the survey collecting in india would have been extremely difficult.
101And some highly promising pathogens especially a rust fungus which seems to hit the seedling and therefore key stage of the target plant
102Floating pennywort Hydrocotyle ranunculoides This is a canal!Floating pennywort Hydrocotyle ranunculoides
103BackgroundHydrocotyle ranunculoides is a serious invader of water bodies in the UKIt is banned in Holland and a recent addition to the EPPO alert list50km stretch was identified in Leicestershire canalControl is extremely difficult and the plant is still spreading
113Thank youShaw, R.H., Bryner, S. & Tanner, R. (2009). The life history and host range of the Japanese knotweed psyllid, Aphalara itadori Shinji: potentially the first classical biological weed control agent for Europe. Biological Control 49: Kurose, D., Evans, H.C., Djeddour, D.H., Canon, P.F., Furuya, N. & Tsuchiya, K. (2009) Mycosphaerella species as potential biological control agents of the invasive weed Fallopia japonica. Mycoscience (in press) Sheppard, A.W., Shaw, R.H. & Sforza, R. (2006) Classical biological control of European exotic environmental weeds: The top 20 potential targets and the constraints. Weed Research 46 pp93-118
114Himalayan knotweedRapidly spreading in UK and N. America and very hard to control. Recent surveys in Pakistan revealed very promising agents……
115Unidentified weevil and rust on Himalayan knotweed in Pakistan