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 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 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 Effects of invertebrate pests on white and annual clovers in dryland soil

2010 ◽  
Vol 63 ◽  
pp. 235-240
Author(s):  
T.M. Eden ◽  
P.J. Gerard ◽  
D.J. Wilson ◽  
N.L. Bell
Keyword(s):  
Plant Growth ◽  
White Clover ◽  
Seedling Survival ◽  
Plant Root ◽  
Subterranean Clover ◽  
Dry Weight ◽  
Cyst Nematode ◽  
Shoot Dry Weight ◽  
Sitona Lepidus ◽  
Clover Root

Two experiments were carried out at Ruakura in soil taken from Whatawhata hill country pasture The relative susceptibility of several annual clovers (Trifolium spp) and perennial white clover (T repens) to slugs (Deroceras reticulatum) clover root weevil (Sitona lepidus) adults native crickets (Nemobius sp) or wheat bugs (Nysius huttoni) was tested by sowing seed of the clovers into separate rows in turf Susceptibility of clovers to clover cyst nematode (Heterodera trifolii) was tested by sowing each clover variety into Whatawhata soil inoculated with the nematode Plant growth was assessed in both experiments 4 weeks after sowing White clover was more susceptible to pests than the annual clovers with slugs and clover root weevil significantly reducing seedling survival and clover cyst nematode significantly reducing plant growth Subterranean clover (T subterraneum) cv Denmark was the least affected by pests showing no significant reduction in survival in the presence of slugs the most damaging pest and no significant decrease in plant root and shoot dry weight when exposed to nematodes

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 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 Relationship between Sitona lepidus larval numbers and white clover seed production

2001 ◽  
Vol 54 ◽  
pp. 141-146
Author(s):  
P.J. Gerard
Keyword(s):  
Seed Production ◽  
White Clover ◽  
Trifolium Repens ◽  
Negative Impact ◽  
Early Flowering ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Second Year ◽  
Clover Seed ◽  
Seed Crops

Plots of two cultivars of white clover (Trifolium repens) Grasslands Prestige (smallleaved early flowering) and Grasslands Kopu (largeleaved later flowering) were established in coldframe beds Clover root weevil (Sitona lepidus) larval numbers were manipulated to obtain winter larval densities ranging from 0 to over 1000/m2 Increasing winter larval densities increased Prestige seed production (g/m2) when harvested on 28 December and 10 January and the trend was still evident on 24 January No such relationships were found in Kopu for the early and middle harvests but at the late harvest increasing winter larval densities had a negative impact on seed production The results indicate that the effect of clover root weevil larvae on second year clover seed crops may vary substantially between cultivars and may even be positive rather than negative

The bionomics of an invasive speciesSitona lepidusduring its establishment in New Zealand

2009 ◽  
Vol 100 (3) ◽  
pp. 339-346 ◽  
Author(s):  
P.J. Gerard ◽  
S.L. Goldson ◽  
S. Hardwick ◽  
P.J. Addison ◽  
B.E. Willoughby
Keyword(s):  
New Zealand ◽  
White Clover ◽  
Sitona Lepidus ◽  
Two Generations ◽  
Boom And Bust ◽  
Clover Root ◽  
Exotic Pest ◽  
Boom And Bust Cycle ◽  
Clover Content ◽  
Adult Abundance

AbstractThe egg, larval, pupal and adult abundance of the clover root weevilSitona lepidusGyllenhal (Coleoptera: Curculionidae) was monitored at three sites for the first ten years following the discovery of this exotic pest in the Waikato region of New Zealand. The species went through an initial boom and bust cycle at two sites, with populations reaching up to 1800 larvae m−2. Thereafter, winter larval populations were relatively stable, ranging between 450–750 m−2. Unlike in the Northern Hemisphere,S. lepiduswas found to have two generations a year in the Waikato region of New Zealand. Pasture white clover content at the time of peak adult numbers was positively related to the subsequent peak larval populations for each generation. The factors contributing to the emergence ofS. lepidusas one of the most important pasture pests in New Zealand are discussed.

scholarly journals Investigations into suitability of Trifolium occidentale as a host plant for two common pasture pests

2014 ◽  
Vol 67 ◽  
pp. 250-255
Author(s):  
P.J. Gerard ◽  
K.M. O'Donnell
Keyword(s):  
Host Plant ◽  
White Clover ◽  
Trifolium Repens ◽  
Stress Factors ◽  
Strong Preference ◽  
Choice Test ◽  
Sitona Lepidus ◽  
Clover Root ◽  
And Performance ◽  
Trifolium Occidentale

Western clover (Trifolium occidentale) is a diploid perennial clover that is reported to be one of the progenitors of white clover (Trifolium repens) The ability to produce hybrids between T repens and T occidentale provides an opportunity to introduce factors to improve white clover tolerance to common stress factors A series of assays was undertaken to compare the feeding and performance of two contrasting pests on two T occidentale lines and two T repens cultivars Clover root weevil (Sitona lepidus) adults showed a preference for T repens but this diminished if weevils had been previously exposed to T occidentale Weevil longevity feeding levels and oviposition were comparable over 32 days indicating T occidentale is a host plant for adult S lepidus Clover flea (Sminthurus viridis) showed a strong preference for T repens over T occidentale in a choice test and higher feeding levels on T repens in the nochoice test

scholarly journals Red clover - a legume showing tolerance to clover root weevil

2003 ◽  
pp. 153-156
Author(s):  
B.M. Cooper ◽  
J.R. Crush ◽  
D.R. Woodfield ◽  
B.E. Willoughby ◽  
K.A. Panckhurst
Keyword(s):  
White Clover ◽  
Dairy Farm ◽  
Field Tests ◽  
Red Clover ◽  
Legume Species ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Lotus Pedunculatus ◽  
Clover Seed ◽  
Potential Tolerance

Clover root weevil (CRW) has now spread through the northern North Island, and south into Taranaki and Hawke's Bay r egions. Sever e infestations can decimate white clover in pasture. In 1998, 2000 and 2002, trials were estab lished on a Warkworth Northland dairy farm to test a range of legume species for resistance or tolerance to CRW damage. Trial lines were regularly assessed for relative vigour and levels of CRW damage. No plant resistance w as identified among white clover, red clover, lucerne, Lotus corniculatus, Lotus pedunculatus or Caucasian clover seed lines. A few lines were adapted to the site and showed tolerance to CRW. Red clover suf fered the least damage and tolerant selections were made from a creeping red clover and nine white clover lines. Two further trials confirmed that red clover showed the least damage. Further cycles of selection are required to develop the potential tolerance shown in field tests. Red clover or a well-adapted white clover offers potential to cope with the CRW stress. Keywords: clover root weevil, clover selections, legume tolerance, Sitona lepidus

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

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