Bacterial association observations in Lucilia sericata and Lucilia cuprina organs through 16S rRNA gene sequencing.

Blowfly (Diptera: Calliphoridae) species Lucilia sericata (Meigen) and related species Lucilia cuprina (Wiedmann) are important agricultural pests, assist in forensic fields and also have a therapeutic role in medicine. Both species (though predominantly L. sericata) are utilised in a clinical setting for maggot debridement therapy (MDT) where the larvae ingest necrotic tissue and bacteria from non-healing wounds. Conversely, larvae of L. cuprina feed invasively, as major initiators of sheep myiasis in Australia, New Zealand, and the UK, among other regions. Both species exhibit larval and adult interactions with bacterially rich environments, but the significance of this in the composition of their microbiome has yet to be considered. This study utilised dissected samples of digestive and reproductive organs from both disinfected and non-disinfected adults and larvae of both species for bacterial DNA extraction, followed by 16S rRNA gene sequencing. Sequencing data indicated unsurprisingly that digestive tracts of both genders and female salivary glands from all non-disinfected samples carry the most concentrated amounts of bacteria. Genera Pseudomonas and Corynebacterium were also highly represented within all organs and species analysed. Comparison of bait lures to sample sequence read output of insect specimens showed no correlation with genera such as Pseudomonas present in insects, while absent from wild bait, and in reduced amounts from fleece bait profiles. With this information, future work can focus on key organs such as the spermathecae and salivary glands, while also providing the potential to identify the role these bacteria may play in the blowfly life cycle. KEY POINTS: Genera Pseudomonas appears consistently in the microbiome of Lucilia species. Female spermathecae and salivary glands show the highest microbial diversity. Bacterial profiles of L. sericata and L. cuprina have similar composition.

Outbreak of caterpillar dermatitis caused by airborne hairs of the mistletoe browntail moth (Euproctis edwardsi).

Caterpillars may be an under-recognised cause of skin and eye reactions. We report a four-month outbreak of recurrent papulourticarial rash among staff and visitors at a community centre. Caterpillar of the mistletoe browntail moth The cause was eventually diagnosed as airborne hairs from (Euproctis edwardsi). caterpillars of the mistletoe browntail moth (Euproctis edwardsi), which infested a eucalypt tree growing in front of the centre. To our knowledge, this is the first clear case of airborne caterpillar hairs causing dermatitis in an indoor environment.

Exotic myiasis with Lund's fly (Cordylobia rodhaini).

After a four-week holiday in East Africa, a woman was diagnosed with furuncular myiasis: a third-instar larva of the fly Cordylobia rodhaini (Lund's fly) was found in a skin lesion. This is the first report of exotic myiasis and importation of this species of fly into Australia, and reflects the increasing risk of introducing exotic flies of public health and veterinary importance to Australia.

The influence of microfilarial density of dog heartworm Dirofilaria immitis on infection rate and survival of Aedes notoscriptus and Culex annulirostris from Australia.

The mosquitoes Aedes notoscriptus and Culex annulirostris, previously shown to be competent vectors of Dirofilaria immitis, were allowed to feed on dogs with densities of microfilariae ranging from 2665 to 33,055 microfilariae/ml. Filaria developed in both species at a similar rate independent of the initial microfilarial density. Cx annulirostris ingested more microfilariae although the number of developing larvae was consistently greater in Ae.notoscriptus; one female Ae.notoscriptus carried sixty-two third-stage larvae 10 days after feeding, although no more than twelve were found in Cx annulirostris. The mortality rate of Ae.notoscriptus in the first 3 days of filarial development was related to increasing microfilarial density, and was greater than that of Cx annulirostris, which quickly reduced its worm load and survived with fewer third-stage larvae but for longer than Ae.notoscriptus. The vector efficiency index was higher at all microfilarial densities for Ae.notoscriptus, but its survival was much reduced, and therefore Cx annulirostris may be the more effective vector in localities where dogs have very high parasitaemias.

The susceptibility of the mosquitoes Aedes notoscriptus and Culex annulirostris to infection with dog heartworm Dirofilaria immitis and their vector efficiency.

The mosquitoes Aedes notoscriptus (Skuse) and Culex annulirostris Skuse were fed on a dog infected with Dirofilaria immitis (Leidy) and a blood parasite count of approximately 5000 microfilaria per ml. Cx annulirostris ingested almost 4 times as much blood and almost 4 times as many microfilariae as Ae.notoscriptus (mean 26.0 compared to 6.6). Attrition of the filarial numbers occurred primarily within the midgut during the first 24 h following ingestion and was greater in Cx annulirostris than Ae.notoscriptus. Aedes notoscriptus sustained development of almost 8 times as many third-stage infective larvae as Cx annulirostris (mean of 3.8 compared to 0.5), and thus had a vector efficiency index of 57.6 compared to 1.9 for Cx annulirostris. In a series of investigations Ae.notoscriptus has now been shown to be an important vector for dog heartworm in southern Australia and may be a significant factor in the apparent burgeoning of the disease.