HISTORY OF WEED BIOLOGICAL CONTROL IN

THE PACIFIC ISLANDS

Warea Orapa

Plant Health Advisor

Land Resources Division

Secretariat of the Pacific Community

Outline of Presentation

1. Background –

– The region

– Alien Weed Impacts

2. History

– Targets, Countries and Agents

3. Information Sources

– Literature

– Regional meetings

The SPC region-22 Pacific Island

Countries and

Territories (PICTs);

-30million km2;

-2% land.

-Excludes Aust.,

Hawaii, Norfolk Is,

Easter Is, & NZ.

1. BACKGROUND –The Region

1. BACKGROUND: Alien Weed Introductions

• 200 years of alien plant introductions.

– Accidental or intentionally introductions;

• Many alien plants have contributed to improving food security and survival of island communities;

• In the Pacific between 300-500 plant species could be regarded as weeds/invaders with at least 150 aggressive invaders impacting one way or the other.

Background cont’d

• Most of the important insect pests and all of the major weeds in the Pacific were introduced;

• The weedy plants tend to have serious impacts for many reasons:

– increasing human populations causing disturbance to natural ecosystems;

– Small islands, far from major continents, low levels of biodiversity, high levels of species endemism (as in Eastern Polynesia) and

– weak defences or competition of native fauna and flora – more opportunities for many of alien plants to establish as weeds.

• Now increasing trade and travel pose greater biosecurity threats to the region.

2. HISTORY of Biological Control

• Globally Weed Biological Control began in the Pacific: Hawai’i and Australia.

– The first deliberate weed biological control work against a weed was on Lantana camara in 1902 in Hawai’i;

– The next major invasive weed problem occurred in Australia. Large areas of land were invaded by introduced cacti like prickly pears (Opuntia spp).

– Biological control was decided as the solution.

• The Pacific region was the first to use biological control for weed management due to the proximity of Hawai’i and Brisbane.

• Biological control as a pest management tool has often been restricted to a few PICTs due lack of capacity.

• Nearly all PICTs rely on the use of weed biological control agents researched elsewhere.

THE TARGETS

3. The Targets

Lantana (Lantana

camara) Verbenaceae

•(since 1902) first weed in the world to be studied for biological control•>600 Lantana varieties, >60 countries/islands affected.•Early and ongoing research has been centred out of Hawaii and Queensland Australia.•Worldwide >40 biological control agents (BCAs) released.•Releases in the PICTs commenced in 1911: •Effective agents are Teleonemia scropulosa, Uroplata girardi, Octotoma scabripennis, Calycomyza lantanae, &Ophiomyia lantanae.•Others like Calycomyza lantanae, Ophiomayia lantanae, Epinota lantana, Lantanophaga pusilidactyla &Hypena laceratalis

•released in a few PICTs but turned up in other PICTs.

Teleonomia scropulosa

Lantana camara BCA Releases in the Pacific Islands

• Ophiomyia lantanae were released in Fiji & New Caledonia(1911);

• Teleonemia scrupulosa. Fiji. 1928

• T. scrupulosa released in New Caledonia & Samoa. 1936.

• Epinota lantana & Lantanophaga pusillidactyla Federated States of Micronesia (FSM). 1948.

• Uroplata girardi – FSM (1963), Cook Is and Fiji (1969), Palau (1974), Niue (1993), .

• Octotoma championi . Fiji (1976)

• Octotoma scabripennis. Fiji (1971), Guam (1971), Cook Is (1973), N.Caledonia (1977), Niue & Solomon Is (1994).

• Generally good control in most islands where all/some of these agents are established and present.

Early Targets

• 12 agents collected from Mexico, USA and Argentina were released in Queensland;

• the moth Cactoblastis cactorium (ex. Argentina, 1925) cleared 24 million ha of prickly pear infestations by 1933.

Prickly pear in Qld before BiocontrolAfter biocontrol at same site. 1933

1933. Cactoblastis cactorium released in New

Caledonia ex. Argentina via Australia.•Successful control of Opuntia stricta

Photos: Queensland Department of Lands and Natural Resources

Kosters curse (Clidermia hirta) Melastomataceae

• 1930. Liothrips urichi shipped from Trinidad were reared and released on Viti Levu &Taveuni islands in Fiji

• - good effective

• 1938, 1973, 1975. L. Urichi released in Solomon Islands ex. Trinidad via Fiji.

• 1956. released in Oahu (Hawaii) ex. Trinidad via Fiji

• 1972. Ategumia ebulealis released in Palau following releases in Hawaii earlier but impacts not known.

Liothrips urichi

Cyperus rotundus (Nutsedge)Cyperaceae

• Bactra venosana released in Fiji, 1936.

• Established but ineffective.

• Athesapeuta cyperi • Not established

• Nutsedge continues to be a common problem weed for agriculture

• Top 10 weeds of Pacific Island agriculture

Puncture vine (Tribulus cistoides) Zygophyllaceae

• 1966. Stem boring weevil Microlarinus lareynii released in PNG. Not established.

• 1967. Microlarinus lypriformis released in PNG. Ex. Hawaii. Established and gives good control

in Morobe & Central Provinces.

Salvinia (Salvinia molesta) Salviniaceae

• The weevil Cyrtobagous salviniae

• Probably the best textbook example of classical weed biological control.

• 1982. Released in Sepik River, PNG.

– >250 sq. km of salvinia mats reduced to just 2 sq.km by 1984!

• 1991. Released in Fiji (Rewa R). Effective

• Also released in Fiji, established but ineffective

– Paulinia acuminata (1975)

– Samea multiplicalis (1976).

– Cyrtobagous singularis (1979)

Salvinia biocontrol in PNG

Before -1982 After -1984

Cyrtobagous salviniae

Photos: CSIRO

Salvinia control on a Sepik River lake system, PNG.

Photo: CSIRO

Water hyacinth (Eichhorniae crassipes) Pontederiaceae

• Neochetina eichhorniae• Fiji (1977), PNG (1986), Solomon Is (1993),

Vanuatu (2005). Effective.

• Nauru (2008). Established.

• Neochetina bruchi - PNG (1993).

Good control in combination with N. eichhorniae)

• Niphgraphta albiguttalis – PNG (1994). Not established.

• Xubida infusella –PNG (1997). Established at 1 site, impacts not significant)

Neochetina eichhorniae

Biocontrol work (in PNG)• 1986-1991. Ad-hoc releases of N. eichhorniae.

Limited impact

• 1993-1998. Intensive rearing and releases of all BCAs. Nationwide control

Neochetina spp reduced reduced

infestations from 100% in 1995 to

10% since 1998

Tambali Lagoon, Sepik River

100% to <1% infestation

Water hyacinth biocontrol in Vanuatu (2005-2008)

May 2008May 2006

Neochetina eichhorniae – rearing pool, Port

Vila

Sensitive Plant (Mimosa diplotricha)

• Widespread.

• Heteropsylla spinulosa releases– 1988. Samoa.

– 1992. FSM.

– 1993. PNG, Fiji

– 1994. Cook Is, SI, Vanuatu, Niue

– Recently detected in Palau (no record of releases)

• Psigida walkeri – Cook Is (not established)

• Scamurius sp – Samoa (Not established)

After Biocontrol

Water lettuce (Pistia stratiotes) Araceae

• Weevil Neohydronomus affinis

• PNG. 1985. Effective

• Vanuatu. 2007. ex. PNG. Effective.

1mm

Biocontrol of Water lettuce in Vanuatu atu

August 2005 (before)Oct 2008 (after)

Broomweeds (Sida spp) (Malvaceae)

• Common weedy species in the Pacific

– Sida acuta & Sida rhombifolia

– Invade open areas including pastures

• 1997-1998. El-Nino induce Sidainvasions in PNG.

– 2000. Calligrapha pantherina released in PNG. ex. Aust

– Effective control at release sites within 12 months!!

• Also released in Fiji (2002) and Vanuatu (2004)

– Effective control

Broomweeds (Sida spp) Biocontrol

2006

Chromolaena (Chromolaena odorata) Asteraceae

• Pareuchaetes pseudoinsulata

– Guam 1985. Good control

– FSM – 1988. Established

– Palau – 1989, 2006. Not established

– PNG – 1998. Establish at 1 location. Not effective.

• Ceccidochares connexa

– Guam & CNMI – Established. effective

– FSM – Established.

– PNG – 2001. Effective.

– Marshall Is. Established.

• Melanagromyza eupatoriella

– Guam. (1984). PNG (2003). Not Establish

• Mescinia nr parvula –

– Guam. Not established.

Mile-a-minute Mikania micrantha Asteraceae

• 1988. Liothrips mikaniae – Solomon Is, ex. Malayasia. Failed to establish.

• 1988. PNG. Failed in Quarantine.

• July 2006 – July 2009.– PNG and Fiji.

– Two species of Actinote spp (July 2006)

– Rust fungi (Puccinia spegazzinii)

• Released & established in PNG (2009) and Fiji (2009)

3. Meetings & Trainings Held

• Pacific Regional Meetings on biological control:– October 1985, Nukualofa, Tonga.

– October 1995, Nadi, Fiji. Resulted in development of dossiers and Pacific Biocontrol Guidelines.

– November 2009. Auckland, New Zealand.

• Past Trainings on Biological Control

– Personnel from Fiji (3), Vanuatu (1), PNG (6), Tonga (1), and Samoa (1) have received 2-week intensive training on Weed biocontrol since 1994 in Brisbane Australia.

• 2004 was last training

– Up to 25 agriculture extension, quarantine and environment personnel from PNG, Solomon Is and Vanuatu were trained in August 2004 on biological control methods.

Literature

• Julien M.H. & Griffiths, M.W. 1998. Biological control of Weeds. A world Catalogue. 4th Edition. CABI.

• Waterhouse, D,F, and Norris, K.R. (1987). Biological Control Pacific Prospects. Inkata Press. Melbourne.

• Day, M.D., Wiley, C.J, Playford, J, and Zalucki, M.P (2003). Lantana: Current management Status and Future Prospects. ACIAR

• Day, M.D., Orapa, W. and Muniappan, R. (2005). Two decades of biological control in the Pacific. Proceedings of the Asia Pacific Weed Science Society Conference, Vietnam.

Thanks