Sarah: Some scientists just inherently know how to communicate.
Entomologist Dr Cameron Webb is one of those people. This week he sent me a wonderful idea for a blog post, and followed up a few days later with this story:
Cameron: The joys of beach combing are well known but what about “bush combing”? Perhaps not quite the same, but after a bit of rain, there is much joy to be had splashing about in puddles, ponds and potholes in your local bushland.
A wet winter weekend is just the time to start sloshing about.
Most of my summer is spent chasing mosquitoes about the wetlands of NSW, from coastal saltmarshes and mangroves to constructed waste-water treatment wetlands. I’m generally targeting specific mosquitoes, tracking changes in abundance and processing them for the detection of pathogens such as Ross River virus. However, Australia boasts a diverse mosquito fauna and many species are found in highly specialised ecological niches. It is often difficult for me to justify spending time hunting down these less common mosquitoes.
One of my favourite environments to explore “for fun” are the sandstone escarpments around Sydney. Amongst the bushland trails, there are often outcrops of sandstone where potholes form and trap rainwater. These mini-wetlands are often thriving ecosystems of aquatic insects and visiting vertebrates but while they may be less well studied than their coastal cousins, they’re still ecologically important.
My daughter and I set off to Buffalo Creek Reserve (near the Field of Mars Environmental Education Centre) with a bag packed with collecting equipment and the ever essential snacks. Miss 6 is a keen insect wrangler having picked up a few skills accompanying me on quick weekend trips to work for maintenance of our laboratory mosquito colonies.
Our main target was a series of freshwater rock pools that, in size and shape are not dissimilar to those of coastal rock shelves. These shallow pools are typically black and on first glance you may be surprised that there is much life in them at all. Stop for a moment and you can see they’re alive with all manner of invertebrates.
There may not be so many frogs about in winter (but these habitats often contain a range of neat tadpoles) but there are still plenty of aquatic invertebrates. There were lots of tiny crustaceans (mostly ostracods and copepods) as well as a few bright red immature stages of chironomids (non-biting midges) but we were mostly interested in the mosquito larvae.
Using an old soup ladle and small disposal plastic pipette, we were able to collect dozens of wrigglers and a few pupae.
We brought them home and over the course of a couple of days what they start to emerge, a process I’m still fascinated by despite watching it happen for over a decade!
There was some surprising diversity in the mosquitoes we collected with a total of four species. Aedes alboannulatus, Aedes notoscriptus, Aedes rubrithorax and Culex quinquefasciatus. Aedes notoscriptus is usually found in artificial water holding containers (e.g. pot plant saucers, discarded tyres, buckets, bird baths etc) and Cx. quinquefasciatus is associated with similar, but generally more polluted, urban habitats. The other two species are typically found in highly ephemeral habitats, Aedes rubrithorax (shown here) almost exclusively in bushland pools like these.
Next time you’re out in the bush after some rain, take the time to stop and have a close look in those puddles, you may be missing a glimpse into some unique bushland biodiversity!
If you’re keen on hunting down some aquatic invertebrates, make sure you pick up a copy of “The Waterbug Book: A guide to the freshwater macroinvertebrates of temperate Australia” by Gooderham and Tsyrlin (CSIRO Publishing).
*Dr Cameron Webb is a Medical Entomologist with the University of Sydney and Pathology West – ICPMR Westmead based at Westmead Hospital, Sydney. You can follow Cameron on Twitter (@mozziebites) or check out his blog http://cameronwebb.wordpress.com/