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 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 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 Collections of Microctonus aethiopoides Loan (Hymenoptera Braconidae) from Ireland

2006 ◽  
Vol 59 ◽  
pp. 290-296 ◽  
Author(s):  
M.R. McNeill ◽  
J.R. Proffitt ◽  
P.J. Gerard ◽  
S.L. Goldson
Keyword(s):  
Biological Control ◽  
New Zealand ◽  
Natural Enemy ◽  
Control Programme ◽  
Sitona Lepidus ◽  
Microctonus Aethiopoides

The biological control programme against Sitona lepidus (Gyllenhal) (Coleoptera Braconidae) commenced in 1998 with the first parasitised weevils imported into New Zealand quarantine in 2000 Extensive collections in Europe confirmed that the solitary endoparasitoid Microctonus aethiopoides Loan (Hymenoptera Braconidae) was the principal natural enemy of adult S lepidus With one exception all M aethiopoides reared from S lepidus collected in Europe have been arrhenotokous All M aethiopoides collected from Ireland are thelytokous which obviates the risk of hybridisation with an arrhenotokous Moroccan strain already established in New Zealand Levels of parasitism in S lepidus fieldcollected from Ireland were low (lt;8) and overall averaged 07 Rates of parasitism of S lepidus in New Zealand quarantine have averaged 25 but ranged from 0 to 95 Aspects relating to the rearing and management of Irish M aethiopoides are discussed including possible reasons for low rates of parasitism in quarantine

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 Fifty years of white clover research in New Zealand

1989 ◽  
pp. 25-39 ◽  
Author(s):  
J.L. Brock ◽  
J.R. Caradus ◽  
M.J.M. Hay
Keyword(s):  
New Zealand ◽  
White Clover ◽  
Grass Species ◽  
N Fixation ◽  
Seasonal Growth ◽  
Considerable Effort ◽  
Pests And Diseases ◽  
Future Developments ◽  
The Past ◽  
Made In

The importance of white clover in New Zealand pastoral agriculture cannot be overstated. It is the major source of nitrogen and by its presence improves pasture quality and balances seasonal growth of grass species. Because of its importance a considerable effort has been put into research on white clover over the past 50 years in New Zealand. This assay reviews the major advances made in white clover use and research from an historical perspective and summarises current understanding and possible future developments. Keywords: white clover, review, history, soil fertility, N cycling, N fixation, nutrition. growth, population structure, management, performance, breeding, pests and diseases, quality.

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 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 Leaf herbivory by clover root weevil adults how much do they eat

2005 ◽  
Vol 58 ◽  
pp. 126-130 ◽  
Author(s):  
P.J. Gerard ◽  
D.L. Hackell
Keyword(s):  
White Clover ◽  
Dry Matter ◽  
Early Summer ◽  
Leaf Damage ◽  
Dry Matter Loss ◽  
Leaf Consumption ◽  
Adult Feeding ◽  
Sitona Lepidus ◽  
Clover Root ◽  
Leaf Herbivory

Populations of adult clover root weevil (Sitona lepidus) can inflict significant numbers of their distinctive feeding notches on the leaves of white clover (Trifolium repens) plants However it is assumed that because white clover is bred for defoliation the damage on established plants has little impact Two experiments were undertaken to quantify the daily leaf consumption levels of adult weevils and how this varied with weevil size and sex clover cultivar and previous leaf damage Overall adults consumed between 075 and 12 mg dry matter/day depending on cultivar and sex Sexual differences were observed between two contrasting clover cultivars with females consuming more Grassland Prestige and males Grasslands Kopu Clover dry matter loss through adult feeding was estimated at about 50 kg/ha from early summer until midwinter in the Waikato the period of peak adult activity

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 Methods to distinguish between the Microctonus aethiopoides strains that parasitise Sitona lepidus and Sitona discoideus

2006 ◽  
Vol 59 ◽  
pp. 297-303 ◽  
Author(s):  
C.B. Phillips ◽  
I.I. Iline ◽  
C.J. Vink ◽  
L.M. Winder ◽  
M.R. McNeill
Keyword(s):  
Biological Control ◽  
New Zealand ◽  
Aldehyde Oxidase ◽  
Mitochondrial Cytochrome ◽  
Cytochrome Oxidase Subunit ◽  
Mitochondrial Cytochrome Oxidase Subunit ◽  
Host Preferences ◽  
Sitona Lepidus ◽  
Microctonus Aethiopoides ◽  
Mitochondrial Cytochrome Oxidase

Two strains of Microctonus aethiopoides with differing host preferences have been released in New Zealand The first was released in 1982 to suppress Sitona discoideus a pest of lucerne and the second was released in 2006 for biological control of Sitona lepidus This paper describes three genetic approaches (esterase isozymes aldehyde oxidase allozymes and nucleotide sequences in a 676 bp region of the mitochondrial cytochrome oxidase subunit one gene) for distinguishing between the M aethiopoides strains A range of research applications for these methods is discussed

Sign in / Sign up

Export Citation Format

Share Document