Palmer C.M.,Northern Territory
Environmental Entomology | Year: 2010
Arid and semiarid environments are characterized by highly unpredictable and 'pulsed'availability of essential biological resources. The 'boom and bust'response of many vertebrates is commonly invoked for invertebrates and especially insects. This perception of the Australian arid zone is exacerbated by the lack of long-term surveys of insects identified at high levels of taxonomic resolution. From an 18 mo continuous survey of insects in central Australia I determine the phenology of many insect taxa, and clarify which climatic variables most influenced the activity of these taxa. Total abundance and taxon richness were higher in the warmer months and lower in the cooler months. Minimum temperature, rainfall during the survey month, and rainfall during the previous month had significant effects on phenology, demonstrating that there is pronounced and predictable activity of many species in the absence of rain, although rainfall has a marked effect on the activity of some species. Other species were more active or only active in the coolest months. These findings have implications for the most productive time for surveys in the Australian arid zone, the availability of insects as prey or pollinators, and for the potential effects of climate change. © 2010 Entomological Society of America.
News Article | November 4, 2015
Scientists from Queensland University of Technology recently discovered a unique genetic code in an Australian tobacco plant which may someday pave way for food production in space. Professor Peter Waterhouse said that they first traced the history of the tobacco plant Pitjuri or Nicotiana benthamiana. The Pitjuri is a "laboratory rat" plant which is often used to test vaccines and viruses. Waterhouse discovered that the plant adapted over-sized seeds as well as rapid reproduction and sacrificed its immune system. To find out how the adaptation works, Waterhouse and his colleagues mapped the gene fault which switched off the Pitjuri's immune system. Their work is issued in the journal Nature Plants. After sequencing the plant's genome and looking into historical records, the team determined that the Pitjuri originated from the harsh desert area near the Northern Territory border and Western Australia. This enabled the tobacco plant to survive and adapt to the hostile environmental conditions. "You'd think it wouldn't be a good thing to have lost your immune system and yet the plant has survived for this length of time and we wondered why," said Waterhouse. He described the process as this: for the plant to survive, it had to germinate and grow very quickly, and place its seed so that when there is rainfall, it can go through its life cycle as fast as it can. This ability is more beneficial to the plant than being able to defend itself from non-existent pathogens in the area, he said. Waterhouse said that the plant's harsh living conditions are almost as hostile as the disease-free environment in space. Researchers believe that their findings could have great impact on biotechnology research and space colonization. Because the team narrowed down the exact gene responsible for the Pitjuri's unique abilities, their next step is to replicate the gene fault in other plants in hopes that they could significantly increase yields on seed crops. Waterhouse explained that it would not be difficult now to test other plant species and knock out the same gene to figure out if they could also produce the same special properties that the Pitjuri has. "It will be interesting to see what a plant will do if you give it this bigger boost of energy to spend in any way it likes," added Waterhouse.
Researchers and Traditional Owners traversed the spectacular reaches of the Prince Regent, Hunter and Roe rivers at night to discover that croc numbers have trebled from 30 years ago when hunting had decimated their numbers. They counted the crocodiles by torchlight, the beam of torchlight reflecting off the crocodiles' eyes gleaming from dark waters. The surveys revealed a healthy croc population, comparable to crocodile numbers in the crocodile-rich waters of the Northern Territory, according to WA Department of Parks and Wildlife (DPAW) scientist Andrew Halford. However, the increase in crocodile numbers combined with warming waters are pushing crocodile populations further south to tourist areas such as Broome, he says, thereby posing new challenges for conservation managers seeking to keep people safe. "We've got a situation where there will be more and more human and crocodile interaction and that's clearly a management issue that we need to keep an eye on," Dr Halford says. "In the news the other day we had a couple of big crocs at Cable Beach that would have posed a serious threat to beachgoers so they were removed and taken to a crocodile park." Some crocodiles in tourist locations in remote areas have lost their fear of humans and pose an elevated risk to visitors, Dr Halford says. Such crocodiles are usually killed, while crocodiles in more accessible areas are translocated away from human populations—a difficult, dangerous and expensive operation. As part of the surveys the team counted the crocs from a five-metre aluminium boat specially adapted for crocodile surveys, with higher-than-standard safety rails and non-reflective black paint on the hull to prevent spotlight reflections. The team felt privileged to work in such a spectacular setting, Dr Halford says, though there were certain encounters that left their hearts racing. "Sometimes we'd be in these little creeks at night time in the middle of nowhere and you'd see a really large croc," he says. "Usually they just disappear but sometimes, when they are not too happy you're there, they'll come towards you at quite a rate." The Dambimangari, Willingin and Wanambal Gaambera Traditional Owners helped conduct the surveys as part of a bigger plan to enable traditional owners to take over the monitoring of plants and animals in their own country.
News Article | November 30, 2015
Bushfires have been ravaging certain areas of South Australia, with two people confirmed dead, 90 victims in the hospital and 87 homes burnt to ashes. More than 27,000 head of livestock have also perished in the bushfires. One man, however, was able to save his house from destruction through quick wits in using smart home technology. Charles Darwin University vice chancellor Professor Simon Maddocks was in Darwin in the Northern Territory of Australia when he was informed of the bushfire ravaging the nearby state. Named the Pinery Fire, the fire was on its way to engulfing Maddocks' property in South Australia, and he would not be able to get there in time to save it as he was 3,000 kilometers away. Using the property's home security, the agricultural scientist watched as the fire approached. Maddocks, however, was not entirely helpless at all. Using an app on his smartphone, he activated the irrigation sprinklers at his property. While his quick thinking was not able to save his crops, which were destroyed by the fire, his farmhouse and animals were able to escape harm. The smart sprinklers played its part in saving the farmhouse and animals, with Maddocks also attributing the rescue to his swift-acting neighbors. "The fire came up all around the house, but my ability to turn on irrigation systems from my phone in Darwin and the fact that I had neighbours patrolling with fire units, we're lucky we got away with a house," Maddocks said. "To suddenly watch your 15 years of labour of love just go to pot in front of your eyes is a bit surreal," Maddocks added, stating that he felt so helpless as he was four-and-a-half hours away when the events unfolded. Maddocks revealed that he will begin to rebuild the property immediately.
So why do they do it and what do they want? Flies are one of the most diverse insect orders, with more than 150,000 species described worldwide in more than 150 different insect families. In Australia, entomologists (scientists who study insects) estimate there are more than 30,000 species of fly, and yet only 7,700 species have been described. There are two main types of fly: the Nematocera (which includes mosquitoes and non-biting crane flies) and the Brachycera (which includes house flies, fruit flies, and horse flies). In Australia, there is only one type of fly that's attracted to us, rather than our blood: the bush fly (Musca vetustissima, Diptera: Muscidae), which is a non-biting fly and close relative of the house fly (Musca domestica). These flies are after the proteins, carbohydrates, salts, and sugars naturally present on your skin. All the other flies around you are probably after your blood, and that includes mosquitoes and horse flies. And yes, unfortunately some people are more attractive to mosquitoes than others. Although mosquitoes and other blood-feeding insects are attracted to the carbon dioxide we exhale, we know the insect sensory system also helps find exposed skin. Since the skin near our faces is often exposed, that's one reason flies are always buzzing around your face and hands. In the mosquito, the proboscis is sharp and needle-like; in the deer fly (also known as the horse fly, or march fly in Australia), it is a large, wide spike. This reflects the different feeding styles found in flies: mosquitoes use a hypodermic needle approach, and are so selective about where they bite research has shown they can actually find capillaries underneath the skin. As most people know, these bites can be very itchy and in rare cases the proteins transferred during a mosquito bite can cause anaphylactic shock. Horse flies use a "slash and suck" approach, where they cut the skin and then lap up the blood that comes out. These bites are my least favourite of any insect. Biting midges, also known as sandflies in Australia, are blood-feeding flies (Diptera: Ceratopogonidae), and are known vectors of lesser human pathogens and major veterinary pathogens in livestock. Their bites are also intensely itchy. Fruit flies and house flies use a slightly different method: their mouthparts are like sponges, and they regurgitate a mixture of digestive enzymes onto the surface they're feeding on and then lap up the resulting liquid. Although they are irritating, they don't bite humans. Along for the ride The biggest problem with fly bites isn't so much that the injury is painful or irritating, it's the pathogens the insect can transmit through their bite. In order for a vector-borne disease to spread, three things need to be present: For some diseases, such as dengue fever, in Australia we have the mosquito but generally don't have the virus. Outbreaks of dengue occur when someone brings the dengue virus into the country, and then the mosquitoes that are already here can spread the disease. When you look at the number of notifications for dengue virus infection, you can see that Queensland has the highest number of cases. But when you factor in the population size, how does that change? When you look at the number of notifications per 100,000 people in the population, the tropical areas of Australia (the Northern Territory, Western Australia, and Queensland) are by far the most at risk. That's because those areas are where you're most likely to have the disease, the insect that spreads the disease, and humans. How can you reduce your risk of being bit? DEET or picaridin containing topical insect repellents work best to stop mosquitoes from biting. Wristbands have been shown not to repel mosquitoes, and botanicals rarely if ever provide the same level of protection. For nuisance flies this may not matter, but for those insects that can carry human disease your best method is to remove all the standing water from around your house (to prevent eggs from developing there), and stay inside when you are able at dusk (to prevent being bit when the mosquitoes are most active). Most blood feeding flies, like mosquitoes, take opportunistic blood meals to complete their lifecycle. The blood meal is required in order for females to lay eggs. In several species of mosquito, females aren't selective and will take their blood meals from a range of vertebrates. Adult males and sometimes females feed only on nectar or pollen. In tabanids like horse flies, nectar feeding occurs frequently in both males and females. When flies land on a series of plants to feed on nectar, they spread the pollen between flowers and help fertilise the next generation of plants. As pollinators, flies perform a valuable role in the ecological community for our native plants, and are also helping farmers. Recent research from scientists in Australia has shown that non-bee pollinators, including flies, play an important role in crop pollination across the world. So next time flies flood your picnic, bushwalk or barbecue, consider that they may have helped put some of that food on your table. Explore further: Researchers investigate new suspect in West Nile deaths of pelicans