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Who's Who in the Biological Control of Weeds

Comprehensive list of weed biocontrol agents under investigation at Manaaki Whenua.
Alligator weed beetle
(Agasicles hygrophila)
Foliage feeder, common, often provides excellent control on static water bodies.
Alligator weed beetle
(Disonycha argentinensis)
Foliage feeder, released widely in the early 1980s, failed to establish.
Alligator weed moth
(Macrorrhinia endonephele)
Stem borer, common in some areas, can provide excellent control on static water bodies.
Blackberry rust
(Phragmidium violaceum)
Leaf rust fungus, self-introduced, common in areas where susceptible plants occur, can be damaging but many plants are resistant.
Boneseed leaf roller
(Tortrix s.l. sp. “chrysanthemoides”)
Foliage feeder, established and quite common at some North Island (NI) sites but no significant damage yet, limited by predation and parasitism.
Bridal creeper rust
(Puccinia myrsiphylli)
Rust fungus, self-introduced, first noticed in 2005, widespread and providing good control.
Broom gall mite
(Aceria genistae)
Gall former, becoming widespread in some regions, beginning to cause extensive damage to broom at many sites, especially in the South Island (SI).
Broom leaf beetle
(Gonioctena olivacea)
Foliage feeder, establishment confirmed at sites in both islands but not yet common, impact unknown
Broom psyllid
(Arytainilla spartiophila)
Sap sucker, becoming common, some damaging outbreaks seen, but may be limited by predation, impact unknown.
Broom seed beetle
(Bruchidius villosus)
Seed feeder, common in many areas, now destroying up to 84% of seeds at older release sites.
Broom shoot moth
(Agonopterix assimilella)
Foliage feeder, recently released at limited sites as difficult to rear, appears to be established in low numbers at perhaps 3 sites.
Broom twig miner
(Leucoptera spartifoliella)
Stem miner, self-introduced, common, often causes obvious damage.
Stripy broom psyllid
(Arytaina genistae)
Accidentally introduced, common in Canterbury and spreading north and south. Similar to broom psyllid, but adults and nymphs can be present all year on broom. Impact unknown .
Californian thistle flea beetle
(Altica carduorum)
Foliage feeder, released widely during the early 1990s, failed to establish.
Californian thistle gall fly
(Urophora cardui)
Gall former, extremely rare as galls tend to be eaten by sheep, impact unknown.
Californian thistle leaf beetle
(Lema cyanella)
Foliage feeder, only established at one site near Auckland, where it causes obvious damage and from which it is dispersing; also recently reported in the Hawke’s Bay.
Californian thistle rust
(Puccinia punctiformis)
Systemic rust fungus, self-introduced, common, damage usually not widespread.
Californian thistle stem miner
(Ceratapion onopordi)
Stem miner, attacks a range of thistles, released at limited sites as difficult to rear, establishment success unknown.
Green thistle beetle
(Cassida rubiginosa)
Foliage feeder, attacks a range of thistles, released widely and some damaging outbreaks beginning to occur.
Chilean needle grass rust
(Uromyces pencanus)
Rust fungus, approved for release in 2011 but not released yet, additional testing is underway with 3 native grass species, only SI populations likely to be susceptible.
Darwin’s barberry flower bud weevil
(Anthonomus kuscheli)
Flower bud feeder, approved for release in 2012; reapplication required
Darwin’s barberry seed weevil
(Berberidicola exaratus)
Seed feeder, releases began in 2015, difficult to rear so widespread releases will begin once harvesting from field is possible, establishment confirmed in Southland.
Field horsetail weevil
(Grypus equiseti)
Foliage and rhizome feeder, field releases began in 2017, establishment is looking likely, further releases ongoing.
Giant reed gall wasp
(Tetramesa romana)
Stem galler, field releases began in late 2017, establishment confirmed at one release site near Auckland.
Giant reed scale
(Rhizaspidiotus donacis)
Sap sucker, approved for release in 2017, first field releases made early in 2021, establishment likely at one site in Auckland, further releases planned.
Gorse colonial hard shoot moth
(Pempelia genistella)
Foliage feeder, from limited releases widely established only in Canterbury, impact unknown, but obvious damage seen at several sites.
Gorse hard shoot moth
(Scythris grandipennis)
Foliage feeder, failed to establish from a small number released at one site, no further releases planned due to rearing difficulties.
Gorse pod moth
(Cydia succedana)
Seed feeder, common in many areas, can destroy many seeds in spring but not as effective in autumn, not well synchronised with gorse flowering in some areas.
Gorse seed weevil
(Exapion ulicis)
Seed feeder, common, destroys many seeds in spring.
Gorse soft shoot moth
(Agonopterix umbellana)
Foliage feeder, common in parts of the SI with some impressive outbreaks seen, well established and spreading at a site in Northland, impact unknown.
Gorse spider mite
(Tetranychus lintearius)
Sap sucker, common, often causes obvious damage, but ability to persist is limited by predation.
Gorse stem miner
(Anisoplaca pytoptera)
Stem miner, native, common in the SI, often causes obvious damage, lemon tree borer has similar impact in the NI.
Gorse thrips
(Sericothrips staphylinus)
Sap sucker, common in many areas, impact unknown.
Heather beetle
(Lochmaea suturalis)
Foliage feeder, has damaged/killed 40,000+ ha heather at Tongariro National Park and Rotorua since 1996, spreading rapidly, uncertain if new strains more suited to high altitude released recently have established.
Hemlock moth
(Agonopterix alstromeriana)
Foliage feeder, self-introduced, common, often causes severe damage.
Hieracium crown hover fly
(Cheilosia psilophthalma)
Crown feeder, released at limited sites as difficult to rear, thought unlikely to have established.
Hieracium gall midge
(Macrolabis pilosellae)
Gall former, established but spreading slowly in the SI, common near Waiouru, where it has reduced host by 18% over 6 years, very damaging in laboratory trials.
Hieracium gall wasp
(Aulacidea subterminalis)
Gall former, established and spreading well in the SI but more slowly in the NI, appears to be having minimal impact although it reduced stolon length in laboratory trials.
Hieracium plume moth
(Oxyptilus pilosellae)
Foliage feeder, only released at one site due to rearing difficulties, did not establish.
Hieracium root hover fly
(Cheilosia urbana)
Root feeder, released at limited sites as difficult to rear, thought unlikely to have established.
Hieracium rust
(Puccinia hieracii var. piloselloidarum)
Leaf rust fungus, self-introduced, common, causes slight damage to some mouse-ear hawkweed, plants vary in susceptibility.
Horehound clearwing moth
(Chamaesphecia mysinformis)
Root feeder, released at limited sites in late 2018, may have established at low levels at one site in the Mackenzie District. Densities too low to confirm establishment.
Horehound plume moth
(Wheerleria spilodactylus)
Foliage feeder, released at limited sites in late 2018, initially thought to have established at sites in North Canterbury and Marlborough, causing obvious damage. Later disappeared from these sites, reintroduction planned in late 2023.
Honshu white admiral
(Limenitis glorifica)
Foliage feeder, field releases began in 2014, already well established and dispersing from site in the Waikato.
Japanese honeysuckle stem beetle
(Oberea shirahatai)
Stem miner, field releases began in 2017, rearing ongoing in preparation for more field releases, establishment confirmed at one site in Canterbury.
Lantana blister rust
(Puccinia lantanae)
Leaf and stem rust fungus, releases began autumn 2015, does not appear to have established to date.
Lantana leaf rust
(Prospodium tuberculatum)
Leaf rust fungus, releases began autumn 2015, established well and causing severe defoliation already at several sites in Northland.
Lantana plume moth
(Lantanophaga pusillidactyla)
Flower feeder, self-introduced, host range, distribution and impact unknown.
Mexican devil weed gall fly
(Procecidochares utilis)
Gall former, common, initially high impact but now reduced considerably by Australian parasitic wasp.
Mexican devil weed leaf fungus
(Passalora ageratinae)
Leaf fungus, probably accidentally introduced with gall fly in 1958, common and almost certainly having an impact.
Mist flower fungus
(Entyloma ageratinae)
Leaf smut, common and often causes severe damage.
Mist flower gall fly
(Procecidochares alani)
Gall former, common now at many sites, in conjunction with the leaf smut provides excellent control of mist flower.
Moth plant beetle
(Freudeita cupripennis)
Root and foliage feeder, field releases began in late 2019 and will be ongoing, some promising early signs that establishment is likely.
Moth plant rust
(Puccinia araujiae)
Rust fungus, approved for release in 2015 but not released yet as waiting for export permit to be granted.
Nodding thistle crown weevil
(Trichosirocalus horridus)
Root and crown feeder, becoming common on several thistles, often provides excellent control in conjunction with other thistle agents.
Nodding thistle gall fly
(Urophora solstitialis)
Seed feeder, becoming common, can help to provide control in conjunction with other thistle agents.
Nodding thistle receptacle weevil
(Rhinocyllus conicus)
Seed feeder, common on several thistles, can help to provide control of nodding thistle in conjunction with other thistle agents.
Old man’s beard mite
(Aceria vitalbae)
Gall former, stunts the new growth, approved for release in 2019, first field releases took place in 2021. Establishment confirmed in several regions of the country.
Old man’s beard leaf fungus
(Phoma clematidina)
Leaf fungus, initially caused noticeable damage but has become rare or died out.
Old man’s beard leaf miner
(Phytomyza vitalbae)
Leaf miner, common, damaging outbreaks occasionally seen, but appears to be limited by parasitism
Old man’s beard sawfly
(Monophadnus spinolae)
. Foliage feeder, limited releases as difficult to rear and only established in low numbers at a site in Nelson, more released in North Canterbury in 2018, establishment confirmed at this site.
Privet lace bug
(Leptoypha hospita)
Sap sucker, releases began spring 2015, establishment confirmed in Auckland and Waikato, some promising early damage seen already in shaded sites.
Cinnabar moth
(Tyria jacobaeae)
Foliage feeder, common in some areas, often causes obvious damage.
Ragwort crown-boring moth
(Cochylis atricapitana)
Stem miner and crown borer, released widely, but probably failed to establish.
Ragwort flea beetle
(Longitarsus jacobaeae)
Root and crown feeder, common, provides excellent control in many areas.
Ragwort plume moth
(Platyptilia isodactyla)
Stem, crown and root borer, recently released widely, well established and quickly reducing ragwort noticeably at many sites.
Ragwort seed fly
(Botanophila jacobaeae)
Seed feeder, established in the central NI, no significant impact.
Greater St John’s wort beetle
(Chrysolina quadrigemina)
Foliage feeder, common in some areas, not believed to be as significant as the lesser St John’s wort beetle.
Lesser St John’s wort beetle
(Chrysolina hyperici)
Foliage feeder, common, nearly always provides excellent control.
St John’s wort gall midge
(Zeuxidiplosis giardi)
Gall former, established in the northern SI, often causes severe stunting.
Scotch thistle gall fly
(Urophora stylata)
Seed feeder, released at limited sites but becoming common, fewer thistles observed at some sites, recent study suggests it can have a significant impact on seed production.
Sydney golden wattle gall wasp
(Trichilogaster acaciaelongifoliae)
Gall former, released at limited sites in 2022 in Manawatū-Whanganui. Establishment not yet confirmed.
Tradescantia leaf beetle
(Neolema ogloblini)
Foliage feeder, released widely since 2011, established well and causing major damage at many sites already.
Tradescantia stem beetle
(Lema basicostata)
Stem borer, releases began in 2012, establishing well with major damage seen at several sites already.
Tradescantia tip beetle
(Neolema abbreviata)
Tip feeder, releases began in 2013, appears to be establishing readily, no significant impact observed yet.
Tradescantia yellow leaf spot
(Kordyana brasiliensis)
Leaf fungus, field releases began in 2018 and are continuing, establishment confirmed at several sites and promising damage seen already at one site in the Waikato.
Tutsan beetle
(Chrysolina abchasica)
Foliage feeder, difficult to mass rear in captivity so limited field releases made since 2017, establishment success unknown but some promising signs seen.
Tutsan moth
(Lathronympha strigana)
Foliage and seed pod feeder, field releases began in 2017 with good numbers released widely, establishment success unknown.
Woolly nightshade lace bug
(Gargaphia decoris)
Sap sucker, established at many sites but only reaches high and damaging densities at shaded sites.