Background: Predicting the host range of biocontrol agents is important for the safe and effective implementation of biocontrol of weeds. In this study, we examined the phylogenetic pattern of host selection and acceptance by the biocontrol beetle, Cassida rubiginosa. The beetle was released in New Zealand for control of Cirsium arvense, its primary host plant, but has potential to attack many Cardueae (thistles and knapweeds) species.
View Article and Find Full Text PDFNew Zealand pastures largely comprising ryegrass species (Poales: Poaceae) are worth $19.6B and are subject to major pest impacts. A very severe pest is the Argentine stem weevil (Kuschel) (Coleoptera: Curculionidae).
View Article and Find Full Text PDFTextile consumer trends towards improved product safety and high environmental standards have significantly influenced regulators in key consumer markets. The apparel wool industry sector has responded to regulators, and for three decades the Australia and New Zealand wool industries have managed advancements in ectoparasiticides and improved sheep treatments targeting high environmental, animal health and welfare standards leading to safe wool products. Australian and New Zealand chemical residue data from greasy wool have been consolidated and analysed for organophosphate, synthetic pyrethroid, insect growth regulator, neonicotinoid, macrocyclic lactone and spinosad active.
View Article and Find Full Text PDFCurvature in mammalian fibers, such as wool and human hair, is an important feature of the functional trait of coat structure-it affects mechanical resilience and thermo-insulation. However, to examine the relationship between fiber curvature, ultrastructure and protein composition fiber diameter variability has to be minimal. To achieve this we utilised the progeny of straight-wool domestic sheep mutant rams (crimp mutants) and wild-type ewes.
View Article and Find Full Text PDFAims: To assess animal health and production in sheep grazing perennial ryegrass () infected with a tall fescue endophyte ( sp.).
Methods: Three replicates of pure perennial ryegrass pastures infected with AR501 tall fescue endophyte (AR501 HE), AR1, AR37 or standard endophyte (STD) (all >85% infection) and a low endophyte control (AR501 LE) were grazed by 10 lambs for 7 weeks during late summer/early autumn, 2017.
The grass grub endemic to New Zealand, Costelytra giveni (Coleoptera: Scarabaeidae), and the manuka beetle, Pyronota festiva and P. setosa (Coleoptera: Scarabaeidae), are prevalent pest species. Through assessment of bacterial strains isolated from diseased cadavers of these insect species, 19 insect-active Serratia proteamaculans variants and a single Serratia entomophila strain were isolated.
View Article and Find Full Text PDFBackground: The insect-pathogenic bacterium Yersinia entomophaga MH96 is currently under development as a microbial pesticide active against various pasture and crop pests such as the diamondback moth Plutella xylostella and the cotton bollworm Helicoverpa armigeria. To enable nonrestricted field trials of Y. entomophaga MH96, information on the persistence and nontarget effects of the bacterium and its Yen-Tc proteinaceous toxin are required.
View Article and Find Full Text PDFBackground: Yersinia entomophaga is an entomopathogenic bacterium that is active against scarab beetles, among other insects. In New Zealand, the African black beetle, Heteronychus arator (Coleoptera: Scarabaeidae), is a major pest of pastures and arable crops but very few control options exist and no insecticides are registered for use in established pastures.
Results: In laboratory bioassays, H.
Evaluating the interconnecting effects of pH, temperature and time on food proteins is of relevance to food processing, and food functionality. Here we describe a matrix-based approach in which meat proteins were exposed to combinations of these parameters, selected to cover coordinates in a realistic processing space, and analyzed using redox proteomics. Regions within the matrix showing high levels of protein modification were evaluated for oxidative and other modifications.
View Article and Find Full Text PDFWool properties and commodity value vary considerably between breeds. In Portugal, three major ovine groups exist: Churros, Bordaleiros and Merinos. This work studies the effect of the ovine genotype on the wool proteome of such groups.
View Article and Find Full Text PDFBackground: Porina is the common name for moths and larvae of the genus Wiseana (Lepidoptera: Hepialidae), some of which are significant pasture pests in New Zealand. Because of environmental concerns and the non-target effects of insecticide control measures, biological alternatives for the control of insect pests such as porina are required.
Results: Using a food preference assay and time-lapse photography, a range of low-cost food ingredients were assessed for their palatability to porina larvae.
The application of the biocontrol bacterium Yersinia entomophaga as a foliar spray was assessed for its efficacy against larvae of the diamondback moth, Plutella xylostella. The bacterium was applied as either a broth suspension, or as a biopolymer-based gel foliar spray and compared with commercial insecticides Dipel (Bacillus thuringiensis) and Spinosad. The performance of Y.
View Article and Find Full Text PDFA highly virulent strain, AGR96X, exhibiting specific pathogenicity against larvae of the New Zealand grass grub (; Coleoptera: Scarabaeidae) and the New Zealand manuka beetle ( and ; Coleoptera: Scarabaeidae), was isolated from a diseased grass grub larva. A 12-day median lethal dose of 4.89 × 10 ± 0.
View Article and Find Full Text PDFAim: To investigate a possible interaction between lolitrem B and ergovaline by comparing the incidence and severity of ryegrass staggers in sheep grazing ryegrass (Lolium perenne) containing lolitrem B or ryegrass containing both lolitrem B and ergovaline.
Methods: Ninety lambs, aged approximately 6 months, were grazed on plots of perennial ryegrass infected with either AR98 endophyte (containing lolitrem B), standard endophyte (containing lolitrem B and ergovaline) or no endophyte, for up to 42 days from 2 February 2010. Ten lambs were grazed on three replicate plots per cultivar.
Aims: To compare ryegrass pastures infected with endophytes producing diverse alkaloids for their ability to cause ryegrass staggers in grazing lambs; to compare respiration rates and rectal temperatures of these lambs after exposure to heat stress, and to compare liveweight gains during the study period.
Methods: Ryegrass pastures of cultivar Trojan infected with NEA endophytes, branded NEA2 (T-NEA2), endophyte-free Trojan (T-NIL), Samson infected with standard endophyte (S-STD), Samson infected with AR37 endophyte (S-AR37) and endophyte-free Samson (S-NIL), were grazed by lambs (n=30 per cultivar) for up to 48 days in February and March of 2012 and 2013. Pasture samples were analysed for alkaloid concentrations and lambs were scored for ryegrass staggers at intervals during the study period.
To determine if host plant abundance determined the size of clover root weevil (CRW) larval populations, a study was conducted over 4 years in plots sown in ryegrass () (cv. Nui) sown at either 6 or 30 kg/ha and white clover () sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establishment and impacts on white clover survival.
View Article and Find Full Text PDFAfrican black beetle, Heteronychus arator (Scarabaeidae), is an exotic pest of pastures in northern New Zealand. Both adults and larvae feed on pasture grasses. Adults disperse by walking (short range) or flying (long range).
View Article and Find Full Text PDFThe majority of herbivorous insects are specialized feeders restricted to a plant family, genus, or species. The evolution of specialized insect-plant interactions is generally considered to be a result of trade-offs in fitness between possible hosts. Through the course of natural selection, host plants that maximize insect fitness should result in optimal, specialized, insect-plant associations.
View Article and Find Full Text PDFBackground and aims Traits related to root depth distribution were examined in Trifolium repens × T. uniflorum backcross 1 (BC1) hybrids to determine whether root characteristics of white clover could be improved by interspecific hybridization. Methods Two white clover cultivars, two T.
View Article and Find Full Text PDFAims: We aimed to evaluate different formulations for their ability to adhere Trichoderma atroviridae spores to wheat seeds, and promote survival during storage at a range of temperatures and relative humidities (RH).
Methods And Results: We tested a range of formulations for their ability to adhere T. atroviridae spores to wheat seeds.
Appl Environ Microbiol
September 2015
The bacterium Yersinia entomophaga is pathogenic to a range of insect species, with death typically occurring within 2 to 5 days of ingestion. Per os challenge of larvae of the greater wax moth (Galleria mellonella) confirmed that Y. entomophaga was virulent when fed to larvae held at 25°C but was avirulent when fed to larvae maintained at 37°C.
View Article and Find Full Text PDFJ Pest Sci (2004)
March 2014
Live organisms intercepted from treated commodities during phytosanitary inspections usually arouse suspicions of treatment failure, sub-standard treatment application, or post-treatment infestation. The additional possibility that some treatments could kill slowly, meaning commodities might be inspected before pests have succumbed, is seldom considered for treatments other than irradiation. We used a novel biochemical viability assay to measure delays between methyl bromide fumigation and mortality of dipteran eggs, and evaluated the correspondence between egg viability and egg morphological features.
View Article and Find Full Text PDFThe disulfide bond network within the cortex of mammalian hair has a critical influence on the physical and mechanical characteristics of the fiber. The location, pattern, and accessibility of free and crosslinked cysteines underpin the properties of this network, but have been very difficult to map and understand, because traditional protein extraction techniques require the disruption of these disulfide bonds. Cysteine accessibility in both trichocyte keratins and keratin associated proteins (KAPs) of wool was investigated using staged labeling, where reductants and chaotropic agents were used to expose cysteines in a stepwise fashion according to their accessibility.
View Article and Find Full Text PDFThermal treatment of meat proteins induces a range of observable and molecular-level changes. In order to understand and track these heat-induced modifications at the amino acid level, various analytical techniques were used. Changes were observed both in the soluble and in the insoluble fractions after hydrothermal treatment of minced beef samples.
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