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 Clover root weevil (Sitona lepidus) - a threat to the sustainability of white clover in New Zealand pastures?

1997 ◽  
pp. 23-27 ◽  
Author(s):  
B. Willoughby ◽  
P. Addison
Keyword(s):  
New Zealand ◽  
White Clover ◽  
Temperate Climate ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Favourable Environment ◽  
The Uk ◽  
Pastoral Farming ◽  
Clover Content ◽  
Clover Pasture

Clover root weevil (Sitona lepidus) is established in Auckland, Waikato and Bay of Plenty provinces. A pasture survey in 1997 estimated that the rate of its spread at about 35 km annually. Adults feed on the foliage and larvae on roots and nodules of white clover. Pasture populations appear to be 10 times higher in New Zealand than in the UK. New Zealand's temperate climate and high clover content in pastures may offer a very favourable environment for S. lepidus, with serious implications for New Zealand's pastoral farming. Keywords: clover root weevil, pasture pests, Sitona lepidus, Trifolium repens, white clover

scholarly journals Effect of deferred grazing during summer on white clover content of Waikato dairy pastures, New Zealand

1999 ◽  
Vol 42 (1) ◽  
pp. 1-7 ◽  
Author(s):  
S. L. Harris ◽  
C. D. Waugh ◽  
R. J. McCabe ◽  
V. T. van Vught
Keyword(s):  
New Zealand ◽  
White Clover ◽  
Clover Content

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 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 Initial establishment of the irish strain of Microctonus aethiopoides in New Zealand

2007 ◽  
Vol 60 ◽  
pp. 203-208 ◽  
Author(s):  
P.J. Gerard ◽  
T.M. Eden ◽  
S. Hardwick ◽  
C.F. Mercer ◽  
M.W.A. Slay ◽  
...  
Keyword(s):  
New Zealand ◽  
White Clover ◽  
Instar Larva ◽  
Early Summer ◽  
Early Winter ◽  
First Instar ◽  
Sitona Lepidus ◽  
Microctonus Aethiopoides ◽  
Made In

Four experimental releases of the parthenogenetic strain of Microctonus aethiopoides from Ireland were made in early 2006 in the Waikato Manawatu (two sites) and Hawkes Bay By early winter establishment was confirmed at all sites with parasitism levels exceeding 10 in the target host Sitona lepidus a serious pest of white clover in New Zealand Subsequent monitoring revealed considerable betweensite variation At the Hawkes Bay and Manawatu Feilding sites where overwintering weevil adults were still present in October over 30 parasitism was found in newly emerged weevils in December 2006 In contrast at the Waikato and Manawatu Bulls sites where there was no overlap of host generations parasitism was below detectable levels during spring and early summer but recovered subsequently The Irish M aethiopoides appears to have four generations a year and diapauses over winter as a first instar larva Following the initial success releases have commenced in other regions

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 Liveweight changes in lambs grazing six perennial ryegrass cultivars

1999 ◽  
pp. 31-35
Author(s):  
C.T. Westwood ◽  
M.G. Norriss
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Dry Matter ◽  
Moisture Stress ◽  
Botanical Composition ◽  
Independent Research ◽  
Ewe Lambs ◽  
Research Organisation ◽  
Clover Content

Liveweight changes were measured for lambs grazing six high endophyte perennial ryegrasses, in a grazing experiment run by an independent research organisation in Canterbury, New Zealand. Ryegrass cultivars were sown under code in a binary mix with white clover in February 1997. Plots were strategically irrigated to avoid moisture stress, and stocked at approximately 27 Coopworth ewe lambs per ha in May 1997. Common pasture residual mass was maintained across cultivars by strategic addition of extra lambs, with extra grazing days recorded for each replicate. Lamb liveweight gains and botanical composition of replicates were assessed quarterly. Lamb liveweight gains differed significantly between treatments in Years 1 and 2 of this ongoing 3 year study. Lambs grazing 'Quartet' tetraploid perennial ryegrass gained, on average, 37.4 kg and 36.1 kg liveweight during Years 1 and 2 respectively, and together with 'Aries HD' (35.0 and 35.9 kg) produced significantly greater liveweight gain compared with 'Grasslands Nui' (22.0 and 23.7 kg) and 'Bronsyn' (22.5 and 24.1 kg), LSD0.05 = 6.0 and 7.4. Lambs grazing 'Embassy' gained 31.6 kg and 28.7 kg, and 'Vedette' 29.8 kg and 28.0 kg. Extra grazing days expressed as a percentage of base grazing days were between 3.8 and 6.7% across cultivars for Year 1 and between 2.0 and 6.5% across cultivars for Year 2. This study demonstrated significant differences in animal productivity between perennial ryegrass cultivars that produce comparable yields of dry matter. Differences may reflect variation in forage quality, endophyte toxins, clover content in the sward or other unidentified cultivar characteristics. Keywords: digestibility, endophyte, lamb, liveweight, perennial ryegrass, tetraploid

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 Managing white clover for productive and profitable sheep farming in Southland

2000 ◽  
pp. 137-140
Author(s):  
J.P.J. Eerens ◽  
D.L. Ryan
Keyword(s):  
Nitrogen Fixation ◽  
New Zealand ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Dry Matter ◽  
Research Station ◽  
Pasture Management ◽  
Pasture Production ◽  
Clover Root ◽  
Pastoral Farming

White clover is often listed as one of the factors contributing to profitable pastoral farming in New Zealand. The positive aspects of white clover have been presented in a balanced manner in publications by scientists, environmentalists and farmers able to exploit these positive aspects. Increasingly, pastures contain sub-optimal levels of clover, as a result of pasture management that is detrimental to clover, including the increasing use of fertiliser nitrogen. In some regions of New Zealand, farmers can legitimately point to pests such as the clover root weevil and factors such as the ryegrass endophyte as causing restrictions in clover production, but this is less the case in Southland. Environmental conditions in Southland are well suited for ryegrass-white clover pastures. Wellmanaged ryegrass-white clover pastures containing the best regional cultivars can achieve high financial returns. A number of trials at the Gore Research Station are reviewed; they demonstrated that on mixed ryegrass-white clover swards farmers can produce nearly 25% more dry matter, 40% more carcass weight and 25% more wool than on pastures with ryegrass alone receiving 270 kg N/ha/year. The yield advantage would have been greater still if they were compared with typical Southland pastures. Not only was 180 kg more carcass and 17 kg more wool produced per hectare on mixed swards, but nitrogen fixation by clover produced more than $300 worth of nitrogen per hectare. The yield advantage achievable from the ryegrass-white clover swards requires specific pasture management, particularly in spring- summer and the use of adapted white clover cultivars. Keywords: cultivars, Lolium perenne, nitrogen, pasture production, perennial ryegrass, set stocking, Trifolium repens, white clover, wool

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

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