Development of a Mycoinsecticide Bait Formulation for the Control of House Flies, Musca domestica L.

The control of house flies, Musca domestica (L.), currently relies on the use of chemical insecticide spray and bait formulations. Entomopathogenic fungi, such as Metarhizium anisopliae, may provide an alternative to these products. This study aimed to develop and evaluate a mycoinsecticide bait formulation containing a virulent M. anisopliae isolate. Five M. anisopliae isolates were screened against M. domestica and isolate M16 was selected for bait development. Bait formulations containing a variety of additives, including (Z)-9-tricosene, were tested for their ability to increase fly visitation. A bait formulation containing M. anisopliae and skim milk powder was found to have the highest house fly visitation and was subsequently compared to a conventional chemical bait in an efficacy assay. The chemical bait (0.5% imidacloprid) caused faster mortality than the mycoinsecticide bait, however, similar levels of mortality were achieved by 4-5 days' post exposure. These results suggest that M. anisopliae mycoinsecticide baits may offer an alternative to conventional chemical insecticides for the control of house flies in suitable areas.

Mitochondrial genomes of Australian chicken Eimeria support the presence of ten species with low genetic diversity among strains.

Modern molecular approaches have vastly improved diagnostic capabilities for differentiating among species of chicken infecting Eimeria. Consolidating information from multiple genetic markers, adding additional poultry Eimeria species and increasing the size of available data-sets is improving the resolving power of the DNA, and consequently our understanding of the genus. This study adds information from 25 complete mitochondrial DNA genomes from Australian chicken Eimeria isolates representing all 10 species known to occur in Australia, including OTU-X, -Y and -Z. The resulting phylogeny provides a comprehensive view of species relatedness highlighting where the OTUs align with respect to others members of the genus. All three OTUs fall within the Eimeria clade that contains only chicken-infecting species with close affinities to E. maxima, E. brunetti and E. mitis. Mitochondrial genetic diversity was low among Australian isolates likely reflecting their recent introduction to the country post-European settlement. The lack of observed genetic diversity is a promising outcome as it suggests that the currently used live vaccines should continue to offer widespread protection against Eimeria outbreaks in all states and territories. Flocks were frequently found to host multiple strains of the same species, a factor that should be considered when studying disease epidemiology in the field.

A molecular survey of Eimeria in chickens across Australia.

Coccidiosis is a costly enteric disease of chickens caused by protozoan parasites of the genus Eimeria. Disease diagnosis and management is complicated since there are multiple Eimeria species infecting chickens and mixed species infections are common. Current control measures are only partially effective and this, combined with concerns over vaccine efficacy and increasing drug resistance, demonstrates a need for improved coccidiosis diagnosis and control. Before improvements can be made, it is important to understand the species commonly infecting poultry flocks in both backyard and commercial enterprises. The aim of this project was to conduct a survey and assessment of poultry Eimeria across Australia using genetic markers, and create a collection of isolates for each Eimeria species. A total of 260 samples (faecal or caecal) was obtained, and survey results showed that Eimeria taxa were present in 98% of commercial and 81% of backyard flocks. The distribution of each Eimeria species was widespread across Australia, with representatives of all species being found in every state and territory, and the Eimeria species predominating in commercial flocks differed from those in backyard flocks. Three operational taxonomic units also occurred frequently in commercial flocks highlighting the need to understand the impact of these uncharacterised species on poultry production. As Eimeria infections were also frequent in backyard flocks, there is a potential for backyard flocks to act as reservoirs for disease, especially as the industry moves towards free range production systems. This Eimeria collection will be an important genetic resource which is the crucial first step in the development of more sophisticated diagnostic tools and the development of new live vaccines which ultimately will provide savings to the industry in terms of more efficient coccidiosis management.

A simple, one-tube assay for the simultaneous detection and diagnosis of ten Australian poultry Eimeria.

Coccidiosis is a costly worldwide enteric disease of chickens caused by parasites of the genus Eimeria. At present, there are seven described species that occur globally and a further three undescribed, operational taxonomic units (OTUs X, Y, and Z) that are known to infect chickens from Australia. Species of Eimeria have both overlapping morphology and pathology and frequently occur as mixed-species infections. This makes definitive diagnosis with currently available tests difficult and, to date, there is no test for the detection of the three OTUs. This paper describes the development of a PCR-based assay that is capable of detecting all ten species of Eimeria, including OTUs X, Y, and Z in field samples. The assay is based on a single set of generic primers that amplifies a single diagnostic fragment from the mitochondrial genome of each species. This one-tube assay is simple, low-cost, and has the capacity to be high throughput. It will therefore be of great benefit to the poultry industry for Eimeria detection and control, and the confirmation of identity and purity of vaccine strains.