scholarly journals Distribution of the clover root weevil biocontrol agent in the North Island of New Zealand

2008 ◽  
Vol 61 ◽  
pp. 24-30 ◽  
Author(s):  
P.J. Gerard ◽  
T.M. Eden ◽  
D.J. Wilson ◽  
G. Burch
Keyword(s):  
New Zealand ◽  
Biocontrol Agent ◽  
Point Sources ◽  
The North ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Successful Establishment ◽  
Set Up ◽  
Microctonus Aethiopoides ◽  
Training And Support

The Irish wasp Microctonus aethiopoides was released in 2006 as a biocontrol agent for the clover root weevil Sitona lepidus a serious pest of white clover in New Zealand Following successful establishment two strategies were implemented to accelerate the widespread establishment of the parasitoid throughout the North Island The first approach was the establishment of regional nursery sites that act as point sources for natural and assisted dispersal With the assistance of Regional Councils and major landowners these were set up at sites favourable to the wasp and local people were provided the training and support to undertake collections and distribution of parasitized weevils Secondly samples of parasitized weevils were distributed for release directly to farmers through pastoral industry networks and events Initial results indicate that while the parasitoid established rapidly at Taranaki and Waikato nursery sites as anticipated it has failed to establish in Northland in two successive seasons

scholarly journals Farmer response to minirelease strategy for the clover root weevil biocontrol agent

2010 ◽  
Vol 63 ◽  
pp. 283-283
Author(s):  
P.J. Gerard ◽  
D.J. Wilson ◽  
T.M. Eden
Keyword(s):  
New Zealand ◽  
Technology Transfer ◽  
Biocontrol Agent ◽  
Good Condition ◽  
High Demand ◽  
Dairy Farmers ◽  
Sitona Lepidus ◽  
Parasitism Rates ◽  
Clover Root ◽  
Microctonus Aethiopoides

The Irish wasp Microctonus aethiopoides was released in 2006 as a biocontrol agent for the clover root weevil Sitona lepidus a serious pest of white clover in New Zealand Following the successful and very rapid establishment of the Irish wasp there was high demand by farmers for the biocontrol Around 2000 minirelease samples were distributed directly to farmers through pastoral industry networks and field days These consisted of ten fieldcollected weevils exposed to the wasp in the laboratory at parasitism rates such that over 99 of samples contained parasitoids A random subsample of 100 recipient dairy farmers was surveyed subsequently by post with 59 responses The minireleases were well received most going to farmers that had previously experienced losses due to the weevil The mini releases were very effective in terms of getting the biocontrol to farms with 92 of insects arriving in good condition and 96 being released on the same day The farmers appeared receptive of the information provided with the samples indicating the project was successful in terms of technology transfer There was good recognition of DairyNZ with 79 showing awareness of the organisations funding enabling the biocontrol research

scholarly journals Rationale for release of the Irish strain of Microctonus aethiopoides for biocontrol of clover root weevil

2006 ◽  
Vol 59 ◽  
pp. 285-289 ◽  
Author(s):  
P.J. Gerard ◽  
M.R. McNeill ◽  
B.I.P. Barratt ◽  
S.A. Whiteman
Keyword(s):  
New Zealand ◽  
Host Range ◽  
Biocontrol Agent ◽  
Hazardous Substances ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Microctonus Aethiopoides ◽  
Poor Efficacy

A European biotype of Microctonus aethiopoides was identified as the best candidate biocontrol agent for Sitona lepidus a serious New Zealand pasture pest A Moroccan biotype was already present throughout the country and hence there was no requirement to obtain Hazardous Substances and New Organisms (HSNO) Act approval to release new biotypes However as research had shown mating between the two biotypes produced hybrids with poor efficacy against target hosts and that the Moroccan biotype attacked several native weevil genera serious reservations were held about introducing the European biotype Concerns were overcome with the identification of a parthenogenetic strain of European M aethiopoides from Ireland which has little risk of hybridisation and a narrower host range than the Moroccan biotype Following regulation of M aethiopoides as a risk species this strain was considered to be a new organism Approval was sought and gained under the HSNO Act to release the strain

scholarly journals South Island distributions of clover root weevil and its biocontrol agent

2010 ◽  
pp. 227-232 ◽  
Author(s):  
C.B. Phillips ◽  
M.R. Mcneill ◽  
S. Hardwick ◽  
C.M. Ferguson ◽  
J.M. Kean
Keyword(s):  
Northern Hemisphere ◽  
White Clover ◽  
Biocontrol Agent ◽  
The North ◽  
Sitona Lepidus ◽  
Clover Root

Clover root weevil (Sitona lepidus) (CRw), a white clover pest from the Northern Hemisphere, was first found in the North island in 1996.

scholarly journals Importation to New Zealand quarantine of a candidate biological control agent of clover root weevil

2001 ◽  
Vol 54 ◽  
pp. 147-151 ◽  
Author(s):  
S.L. Goldson ◽  
C. Phillips ◽  
M.M. McNeill ◽  
J.R Proffitt ◽  
R.P. Cane
Keyword(s):  
Genetic Diversity ◽  
Biological Control ◽  
New Zealand ◽  
Biological Control Agent ◽  
Genetic Material ◽  
Control Agent ◽  
Biological Control Agents ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Microctonus Aethiopoides

Several candidate biological control agents of Sitona lepidus have been identified since a search commenced in 1997 Interestingly Microctonus aethiopoides from Europe is a much more effective parasitoid of S lepidus than the M aethiopoides ecotype already established in New Zealand To assess further the suitability of the European M aethiopoides for biological control of S lepidus 1599 infected S lepidus were shipped to New Zealand quarantine during late 2000 These yielded 267 parasitoid pupae from which 204 adult parasitoids were reared This material was obtained from a wide geographical range in Europe and has been used to establish cultures in New Zealand quarantine based on genetic material from France England Norway Finland Romania Ireland Scotland Italy and Wales This contribution presents an overview of the work associated with the importation of the parasitoids and the effort now being made to maintain genetic diversity Planned research is also discussed

scholarly journals The effect of parasitism on clover root weevil flight capability

2008 ◽  
Vol 61 ◽  
pp. 31-34
Author(s):  
T.M. Eden ◽  
M. Donald ◽  
P.J. Gerard
Keyword(s):  
New Zealand ◽  
Flight Activity ◽  
Biocontrol Agents ◽  
Passive Dispersal ◽  
First Instar ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Flight Muscles ◽  
Microctonus Aethiopoides

The Irish strain of Microctonus aethiopoides was released in New Zealand in 2006 to help suppress populations of the clover pest clover root weevil (Sitona lepidus) A study was undertaken to determine if this parasitoid will be passively dispersed through flight activity by parasitized hosts In the laboratory Irish M aethiopoides parasitized equally hosts with or without flight muscles and subsequent presence of parasitoid eggs or first instar larvae had no effect on the propensity for S lepidus to prepare to take flight during laboratory observations In the field significantly fewer clover root weevil with flight muscles were found to be parasitized compared to those without flight muscles and those that were parasitized contained predominantly eggs and first instar larvae The results were compared with other Microctonus biocontrol agents released in New Zealand and it was concluded that passive dispersal should play a major role in dispersing Irish M aethiopoides in New Zealand especially in warm dry summers

scholarly journals Clover root weevil in the South Island detection response and current distribution

2007 ◽  
Vol 60 ◽  
pp. 209-216 ◽  
Author(s):  
C.B. Phillips ◽  
M.R. McNeill ◽  
S. Hardwick ◽  
C.J. Vink ◽  
J.M. Kean ◽  
...  
Keyword(s):  
Biological Control Agent ◽  
New South ◽  
Control Agent ◽  
The South ◽  
The North ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Detection Response ◽  
Microctonus Aethiopoides ◽  
Intensive Sampling

Sitona lepidus had spread throughout the North Island of New Zealand by 2005 and was first detected in the South Island in January 2006 when one individual was found at Harewood Christchurch Intensive sampling during February 2006 recovered only two additional specimens Several specimens were recovered from a separate Christchurch location in August 2006 Localised S lepidus populations were discovered near Richmond Nelson in April 2006 and in Rai Valley in May 2006 A website established in May 2006 to provide information about S lepidus was visited a mean of 135 times per month but it was never used to report possible new South Island infestations A biological control agent Microctonus aethiopoides was released at Richmond and Rai Valley between August 2006 and March 2007 By May 2007 it was parasitising from 4 to 14 of S lepidus adults which indicates it is likely to become permanently established

scholarly journals Status of clover root weevil and its biocontrol agent in the South Island after six years.

2012 ◽  
pp. 171-175 ◽  
Author(s):  
C.M. Ferguson ◽  
M.R. Mcneill ◽  
C.B. Phillips ◽  
S. Hardwick ◽  
D.M. Barton ◽  
...  
Keyword(s):  
Biocontrol Agent ◽  
Parasitoid Wasp ◽  
The South ◽  
Natural Spread ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Microctonus Aethiopoides ◽  
Made In

Clover root weevil was first discovered in the South Island in 2006. Since then its distribution has been monitored. Although not yet occurring throughout all the South Island, it is widespread and has become common in many regions. The first releases of a biocontrol agent, the Irish ecotype of the parasitoid wasp Microctonus aethiopoides, were also made in 2006, with more made as suitable weevil populations were detected. In all areas where the releases have been monitored the biocontrol agent has established and extensive natural spread has occurred from the earlier release sites. As a consequence it is now established extensively in the northern South Island. Targeted releases have established the agent in Canterbury, Otago and Southland. Keywords: Biocontrol, clover root weevil, Sitona lepidus, Microctonus aethiopoides

scholarly journals Clover root weevil biocontrol distribution in the North Island - release tactics and outcomes

2010 ◽  
pp. 85-89
Author(s):  
P.J. Gerard ◽  
D.J. Wilson ◽  
T.M. Eden
Keyword(s):  
Technology Transfer ◽  
White Clover ◽  
Trifolium Repens ◽  
Biocontrol Agent ◽  
Postal Survey ◽  
Far North ◽  
The North ◽  
Field Samples ◽  
Clover Root ◽  
Microctonus Aethiopoides

Clover root weevil (CRW) has become one of New Zealand's most serious pasture pests. An Irish ecotype of Microctonus aethiopoides has been released and established as a biocontrol agent. Since early 2006, field samples have been taken to monitor its spread and establishment. The biocontrol agent has established well at sites where 1 000-2 500 parasitised CRW were initially released, except in the Far North, and is spreading at around 15 km/year. Industry field personnel assisted with distributing 2 000 mini-releases (10 parasitised CRW) to areas where CRW was causing damage. One hundred farmers were sent a postal survey and feedback from 59 respondents showed the mini-release approach was successful in terms of distribution of the parasitoid, technology transfer and funder recognition. Based on natural spread from many of the release sites, it is predicted that the parasitoid will be present on most North Island farms by the end of summer 2010/2011. Keywords: Microctonus aethiopoides, biocontrol agent, white clover, Trifolium repens

scholarly journals Investigation into the delayed establishment of Microctonus aethiopoides in Northland

2009 ◽  
Vol 62 ◽  
pp. 414-414
Author(s):  
T.M. Eden ◽  
P.J. Gerard ◽  
J.J. Dymock ◽  
N. Ahmad
Keyword(s):  
New Zealand ◽  
High Mortality ◽  
Far North ◽  
Larval Diapause ◽  
Sitona Lepidus ◽  
Critical Photoperiod ◽  
Clover Root ◽  
Microctonus Aethiopoides ◽  
Multiple Releases ◽  
Collection Sites

The Irish strain of Microctonus aethiopoides was released in New Zealand in 2006 to help control clover root weevil (Sitona lepidus) Establishment was rapid at all release sites except in Northland where multiple releases appeared to fail until low numbers were recovered in 2008 It was hypothesised that because Northland at 35S is at sufficiently different latitude to the original collection sites near Belfast Ireland (5437N) there is a crossing of the critical photoperiod for diapause induction in the wasp larvae Replicated cage trials were undertaken to compare the prevalence of premature diapause in Northland with Waikato under natural daylength and simulated Far North midsummer photoperiod (1410 h light dark) with a 16 h photoperiod Results indicated that larval diapause inside the weevil may be initiated by the parent wasp as significantly more 1st instar larvae were present in weevils where wasps had been subjected to reducing daylength (16 h down to 14 h light) High mortality amongst singlylaid wasp larvae in the Northland summer and the absence of teratocytes usually associated with larvae indicates clover root weevil adults can defeat a singlylaid parasitoid These results may explain the reduced efficacy of the Irish wasp in Northland

scholarly journals Abundance and parasitism of clover root weevil (Sitona lepidus) and Argentine stem weevil (Listronotus bonariensis) in pastures

2012 ◽  
Vol 65 ◽  
pp. 180-185 ◽  
Author(s):  
P.J. Gerard ◽  
M. Vasse ◽  
D.J. Wilson
Keyword(s):  
Life Cycle ◽  
Retrospective Study ◽  
Severe Drought ◽  
Host Availability ◽  
The North ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Listronotus Bonariensis ◽  
Microctonus Aethiopoides ◽  
Microctonus Hyperodae

The period from 2006 to 2010 in the North Island encompasses the widespread establishment of Irish Microctonus aethiopoides for the biocontrol of clover root weevil (Sitona lepidus) and a severe drought in 2008 that greatly reduced host availability This parasitoid occupies the same pasture habitat as Microctonus hyperodae a parasitoid with a similar life cycle introduced to control Argentine stem weevil (Listronotus bonariensis) A retrospective study was carried out on L bonariensis data and stored samples collected during S lepidus studies It was found that at all four initial M aethiopoides release sites L bonariensis populations were lowest in 2007 and 2008 while S lepidus populations were lowest in 2008 and 2009 Microctonus hyperodae parasitism levels were lowest in 2009 with overall regional means ranging from 5 in Manawatu to 11 in Waikato whereas corresponding Irish M aethiopoides parasitism levels were 43 and 72 respectively

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