Insect damage to grasses oversown into tussock grassland in Central Otago, New Zealand

Bremner, Graeme

doi:10.1080/00288233.1991.10417669

Cited by 2 publications

(2 citation statements)

References 9 publications

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“…Many species, especially in the tribe Entimini, are flightless, with soil-dwelling, root-feeding larval stages (May 1993). Adults typically feed on a wide range of host plants (Bremner 1988) and can damage introduced exotic grass and legume species (Barratt et al 1992;Bremner 1991). They occur naturally in a wide range of habitats, particularly in native grassland and sub-alpine and alpine herb fields.…”

Section: Introductionmentioning

confidence: 99%

Phenology of native weevils (Coleoptera: Curculionidae) in New Zealand pastures and parasitism by the introduced braconid,Microctonus aethiopoidesLoan (Hymenoptera: Braconidae)

Barratt

Ferguson

Evans

et al. 2000

New Zealand Journal of Zoology

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The phenology of native brachycerine weevil species at seven pasture sites in Otago, Canterbury and Waikato was studied by regular quantitative sampling of adults. Weevils were identified to species, and dissected to record reproductive status and parasitism by introduced braconid parasitoids in the genus Microctonus. Climatic data assisted in the interpretation of some population density patterns. Weevil population density was estimated for periods of two to five years at the selected sites. Species in the Entimini (species of Irenimus and Nicaeana) were generally univoltine, with adults Z99025 emerging in winter-spring. The main period of reproductive activity was spring, and parasitism by Microctonus aethiopoides reached its highest incidence in January. Low level parasitism of native weevil species by M. aethiopoides was detected at all sites, and by M. hyperodae at two sites. At one site in Otago, parasitism by M. aethiopoides was higher and could have affected the population density of Irenimus aemulator (Broun) and Nicaeana sp. Most parasitism occurred after the main reproductive period of weevils in spring, but a putative second generation in some species might be more affected by parasitoid attack. A native rhytirhinine species, Steriphus variabilis, differed from the entimines because adults emerged in autumn and spring, and may be bivoltine. Mechanisms of M. aethiopoides parasitism of non-target species in the field are discussed.

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Section: Introductionmentioning

confidence: 99%

Phenology of native weevils (Coleoptera: Curculionidae) in New Zealand pastures and parasitism by the introduced braconid,Microctonus aethiopoidesLoan (Hymenoptera: Braconidae)

Barratt

Ferguson

Evans

et al. 2000

New Zealand Journal of Zoology

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“…The test insect chosen was the adult stage of Nicaeana cervina Broun (Coleoptera: Curculionidae: Entiminae), a New Zealand native species that has adapted to introduced pasture environments. This weevil feeds on white clover [ Trifolium repens L. (Fabaceae)] (Barratt et al., 1992) and ryegrass [ Lolium perenne L. (Poaceae)] (Bremner, 1991) and is relatively easy to maintain in the laboratory from field‐collected individuals (Grainger, 1995). This allowed us to examine weevil survival, feeding, and reproductive performance on these plant species.…”

Section: Introductionmentioning

confidence: 99%

Developing a method for laboratory biosafety testing impacts of transgenic plants on non‐target insects

Barratt

Crook

Ferguson

et al. 2008

Entomologia Exp Applicata

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A series of laboratory experiments was carried out with the main objective of contributing to the development of biosafety testing methods for transgenic plants or plants produced by other novel technologies. The adult stage of a New Zealand native weevil, Nicaeana cervina (Broun) (Coleoptera: Curculionidae: Entiminae), was used as a test insect as this has become well‐adapted to introduced pasture species, feeding on both ryegrass [Lolium perenne L. (Poaceae)] and white clover [Trifolium repens L. (Fabaceae)]. Ryegrass plants used in experiments were infected with strains of the symbiotic endophytic fungi Neotyphodium lolii (Latch, M.J. Chr. & Samuels) and Epichloe festucae Leuchtm., Schardl & M.R. Siegel and included a transgenic endophyte, which was modified to eliminate production of the insect deterrent, peramine. Nicaeana cervina was exposed to these endophyte‐infected plants along with endophyte‐free ryegrass. Weevils were also exposed to white clover with high or low levels of cyanogens, and to white clover selections bred conventionally to contain high or low levels of crude protein. These bioassays were carried out sometimes over a series of time intervals, and weevil survival, feeding, and reproductive performance variables were measured. Nicaeana cervina survival was generally high, although feeding and oviposition were variable between experiments despite high replication in some cases. A summary of significant differences obtained across all experiments suggested that data on the proportion of weevils feeding and amounts of leaf material consumed were more often significantly different than treatment effects on survival or reproductive performance. A positive relationship between the proportion of weevils feeding and those ovipositing was found, suggesting that a 50% reduction in feeding would result in a 28% reduction in the proportion of weevils ovipositing. Power analysis using the range of values recorded for the variables measured indicated that for proportions of weevils surviving, feeding, or fecund, about 35–42 replicates would be required for a 40% difference in values. For measures of leaf consumption and numbers of eggs per female, fewer replicates were required for 95% power when these values were at the higher end of the range than when they were at the lower end of the observed range. The usefulness of the case study test insect and risk assessment protocols used for biosafety testing are discussed.

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Insect damage to grasses oversown into tussock grassland in Central Otago, New Zealand

Cited by 2 publications

References 9 publications

Phenology of native weevils (Coleoptera: Curculionidae) in New Zealand pastures and parasitism by the introduced braconid,Microctonus aethiopoidesLoan (Hymenoptera: Braconidae)

Phenology of native weevils (Coleoptera: Curculionidae) in New Zealand pastures and parasitism by the introduced braconid,Microctonus aethiopoidesLoan (Hymenoptera: Braconidae)

Developing a method for laboratory biosafety testing impacts of transgenic plants on non‐target insects

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