There has been some public concern over a possible increase in blowfly numbers since the introduction of Wheelie bins. Some opinion attributes this possible increase in blowfly numbers to the reduction in bin collection frequency from twice per week to once per week. To aid in resolving the issue the Medical Entomology Branch of the NT Department of Health and Community Services, set up an experiment to determine what link existed between Wheelie bins and blowfly numbers.

The Top End of Australia is home to plenty of creatures such as mosquitoes, biting midges, and a wide range of other insects that can leave locals and visitors alike with some unwelcome pain or discomfort, as well as possibly contracting an insect borne disease. Faced with the daunting array of biting insects, many people often ask, “what is the health risk of this or that insect, what is the best way to protect against the bites and stings, what repellent is the best, or even do sand flies really urinate on your skin?” This introduction to the various culprits and the range of ways to protect yourself will hopefully help make your life in the Top End a bit less painful and safer.

A biting insect assessment was conducted at the Andranangoo Creek West and Lethbridge Bay West mining prospects from the 29th September to the 1st of October 2005. This included detailed ground surveys for actual and potential mosquito breeding sites, assessment of aerial photography for potential mosquito and biting midge breeding sites, and initial adult biting insect trapping at both mining prospects. The early report production meant that information from subsequent peak season adult biting insect trapping in November 2005, and January and May 2006 had to be produced in a separate supplementary report. Therefore some conclusions in the first report were drawn based on field inspections and desktop observations, and not on trap data. The following report highlights the findings of the supplementary trapping, with new conclusions in regards to mosquitoes and biting midges. Trapping conducted for the Andranangoo Creek West and Lethbridge Bay West Biting Insect Assessment Report (Warchot & Whelan 2005) is referred to as ‘initial trapping’ in this supplementary report.

Burnside Operations Pty Ltd plan to commence mining at the North Point and Princess Louise mine sites, located in the East Burnside Project Area approximately 130km south-east of Darwin. The mining method will be open cut, with ore to be transported to Union Reefs Gold Mine for processing. Workers are to be housed at the mine camp at Cosmo Village. Mine sites have the potential to create or exacerbate mosquito breeding, potentially from the creation of water dams, wetland filters, borrow pits, sediment traps, dry season water discharge, waste water disposal, as well as the construction of roads and mine waste dumps. Mine sites also have the potential to introduce new mosquito species into the Northern Territory, such as the dengue mosquito Aedes aegypti from North Queensland, if equipment was to be sourced from this area. As part of the environmental process, all major development in the NT is required to consider mosquitoes during the preparation of Environmental Impact Statements or Public Environmental reports, to ensure new development does not create new mosquito breeding sites, and also to protect the health of workers.

Matilda Minerals Limited (Matilda) proposes to develop sand mining operations at Andranangoo Creek West (Andranangoo) and Lethbridge Bay West (Lethbridge), Melville Island, Tiwi Islands, Northern Territory. The proposed operation will extract high grade heavy minerals (HM), specifically zircon and rutile, for export to China. It is estimated that a total of 99,000 t of zircon and rutile will be exported during the anticipated sand mining operation over three and half years. A proposal to mine both sites was submitted to the NT Government in the form of a Notive of Intent Document (URS, 2005). The NT Government determined the project is to undergo formal environmental assessment in the form of an Environmental Impact Assessment (EIS). Part of the EIS process is to conduct a biting insect assessment of the general project areas to determine any public health risks to workers and the potential for mining activities to alter the natural environment and create further biting insect breeding sites. The Medical Entomology Branch was commissioned by URS Australia on behalf of Matilda Minerals to undertake a biting insect assessment at both proposed sandmining sites.

A Hazchem Storage Facility is proposed at Section 4239, Hundred of Bagot. Section 4239, Hundred of Bagot is located at Hidden Valley adjacent to extensive mangrove areas of Bleesers Creek and Reichardt Creek in Frances Bay, Darwin Harbour. Section 4239 is proposed to be subdivided in future, with the proposed Hazchem Storage Facility to be built within a 4ha site in Section 4239. The areas adjacent to the proposed development area were also identified as being subject to seasonal pest problems from the salt marsh mosquito Ochlerotatus vigilax (Whelan et al 1994). Other mosquito species of potential significance in the proposed development area include Culex annulirostris and Coquillettidia xanthogaster (Whelan et al 1994). Ochlerotatus vigilax is a vector of Ross River virus (RRV) disease and Barmah Forest virus (BFV) disease, while Culex annulirostris is a vector of RRV, BFV, Murray Valley encephalitis virus (MVEV) disease and Kunjin virus (KUNV) disease. The numbers of these species of mosquitoes in this area indicated there are seasonal risks for mosquito borne disease transmission in the development area. The Medical Entomology Branch (MEB) has been asked to identify any biting insect pest or potential human health problems in the development area, and provide advice on the magnitude of the problem. To do this MEB has referred to past biting insect investigations in the development area (Whelan et al 194), as well as examined the proposed plans for the potential of the development to create or exacerbate existing biting insect problems.

The objectives of the biting insect assessment of the proposed Darwin City Waterfront Redevelopment area is to outline actual and potential biting insect problems within the redevelopment area, and to provide mitigation strategies to prevent or minimise biting insect problems. As with most coastal areas in the NT, the proposed development area is potentially subject to mosquito and biting midge pest problems, and potential mosquito borne disease problems.

The Blacktip Project consists of both offshore and onshore components. The onshore components include the construction and operation of an onshore processing plant, construction and operation of 3km of buried onshore pipeline, and the construction of access roads and construction camp. There were potential biting insect concerns associated with these onshore components of the Blacktip Project. EcOZ Environmental Services was commissioned by Woodside Energy Limited (Woodside) to assist in the preparation of a Draft Environmental Impact Statement (EIS) for the Blacktip Project. EcOZ Environmental Services then commissioned the Medical Entomology Branch of the Department of Health and Community Services to provide information on biting insects likely to affect the Blacktip Project.

Milingimbi is an Aboriginal community in Arnhem Land, 206 km West from Nhulunbuy. The population is 920 (NT government intranet, 30/6/2003). The community is located on Milingimbi Island. Near the end of February 2003 the Milingimbi community council expressed concerns over increased mosquito numbers to Environmental Health, who requested the Medical Entomology Branch to visit the community, assess the situation and advise on strategies to reduce mosquito problems. Two MEB officers visited Milingimbi on 7-9 April 2003 and carried out a comprehensive biting insect survey, including biting insect trapping, larval mosquito surveillance and a receptacle survey. The results of this survey and the assessment are presented in this report. A mosquito survey had previously been carried out in Milingimbi in 1983, and was documented in a MEB branch report.

There are many examples of development in the Darwin region that have led to enormous populations of a range of mosquito species, severely effecting residents in nearby areas and requiring costly rectification. To aid planners in their design of the proposed Newton development, the Medical Entomology section of the department of Health and Families has made collections of biting midges and mosquitoes form march 1984 to April 1985 in and around the proposed development area between the Elizabeth and Blackmore Rivers, south-west of Palmerston. Additional surveys of biting midge breeding areas were made in late 1987. This report analyses the result and suggest methods of minimising the adverse effects of the biting insect present in the proposed development area, and outlines some construction guidelines to avoid exacerbating the problem.

Compass Resources NL is proposing the development of the Browns Oxide mine, located in the Northern Territory approximately 65km south of Darwin and 7km north-west of Batchelor (Figure 1).The project is currently under construction. Compass Resources NL proposes to utilise open cut mining methods and a conventional hydrometallurgical process to extract approximately 3.9 million tonnes of oxide ore and produce copper, cobalt and nickel over a four year period (Public Environmental Report (PER) - Enesar Consulting Pty Ltd 2005). Mine sites have the potential to create or exacerbate mosquito breeding, from the creation of water dams, wetland filters, borrow pits, sediment traps, pit water discharge, waste water disposal, as well as the construction of roads and mine waste dumps. Mine sites also have the potential to introduce new mosquito species into the Northern Territory, such as the dengue mosquito Aedes aegypti from North Queensland, if equipment is sourced from this area. Therefore, all major development in the NT is required to consider mosquito breeding during the Environmental Assessment process, to ensure development does not create new mosquito breeding sites.

Cockroaches can be significant pest and potential public health problems in the tropics. The guide and recommendations below have been produced with public buildings in mind but can equally apply to private premises. They have been aimed at the German cockroach as they are more common in institutions and residential premises in the Northern Territory but the principles apply equally to the larger American cockroach. They are aimed at the owner or occupier conducting the control, rather than engaging a licensed pest control operator.

In April 1992 the Darwin City Council approached the Medical Entomology Branch, Department of Health & Community Services to conduct a trial to determine the efficacy of Enviroblox insecticidal blocks against blowflies and their larvae in wheelie bins. These blocks consisted largely of napthalene with 2% permethrin. Initial trials indicated that the insecticidal activity of the blocks was not adequate for effective control (especially of larvae). A second batch of Enviroblox insecticidal blocks containing 10% dichlorvos with napthalene were tested against blowflies and their larvae. Under the trial conditions these blocks killed blowflies within half an hour and larvae within six hours. Shelltox Ministrips which contain 18.6% dichlorvos were found to kill blowflies and larvae as effectively as the insecticidal blocks. Larvae feeding on organic matter within plastic bags may be protected from the insecticide vapour in the bin air space. However once larvae escape from the bags to search for pupation sites or more food they are likely to come into contact with a lethal dose of insecticide. The report concludes that a trial of the blocks in household wheelie bins in part of Darwin should be undertaken to confirm the trial results reported here.

The towns of the "Top End" of the Northern Territory are to various degrees adjacent to tropical wetlands, localised swamps, or wet season flooded areas, which can produce seasonally high numbers of a range of pest and potential vector mosquito species. These towns are both receptive and vulnerable to a number of endemic mosquito borne virus diseases including epidemic polyarthritis. Barmah Forest disease, and Australian encephalitis. Due to the proximity of some residential areas of Darwin to extensive wetlands and the large number of residents potentially exposed to mosquito attack, this city has the most comprehensive mosquito control program. The other towns in the Northern Territory have mosquito control programs that are appropriate to their locality, their specific mosquito problems and the practicality of various control methods. This paper outlines an overview of current insecticide mosquito control programs in the Northern Territory, with details of the extensive aerial larval control program and prospects for future control.

A dengue outbreak has been underway in Timor Leste (East Timor) since the start of January 2005, with hundreds of cases and multiple deaths from dengue haemorrhagic fever/dengue shock syndrome reported by the Ministry of Health (MOH) Timor Leste. The Northern Territory Department of Health and Community Services (DHCS) received a formal request from the Minister of Health Timor Leste on 05/04/2005 to provide advice to overcome the current outbreak and for a longer-term program to combat dengue disease in Timor Leste. This request was discussed with key DHCS officers and Ausaid officers, who supported a visit by the director of Medical Entomology Branch to conduct an assessment of the current dengue control program and to provide advice on strengthening the dengue control program.

This article summerises the recent successful program to eliminate an incursion of the dengue mosquito, Aedes aegypti from Tennant Creek in the Northern Territory.

This article reviews the past establishment of the dengue mosquito Aedes aegypti in the Northern Territory, provides an update on the current elimination program in place in Tennant Creek and explores local and national implications of the incursion.

Incursions of the exotic Asian Tiger mosquito, Aedes albopictus, were detected in Darwin port areas in the Northern Territory on the 28 November and 5 December 2013. During both incursions, 1 adult female Ae. albopictus was collected in a Biogents (BG) sentinel trap at Toll Marine Logistics (TML) and the Darwin East Arm Wharf (EAW)respectively. Both incursions coincided with the berth of international vessels at the TML and EAW port facilities. In response to both incursions, all receptacles in the port facilities and adjacent premises were treated with residual insecticide and adult mosquito control (fogging) was carried out. Enhanced exotic mosquito surveillance was established to monitor for exotic mosquitoes. There have been no further detections of Ae. albopictus at TML or EAW.

Energy Resources of Australia (ERA) Ranger Mine is located in Kakadu National Park, adjacent to several arms of the Magela Creek and within flight range of mosquitoes from the extensive Magela Swamp. Weekly routine adult mosquito trapping in and adjacent to the nearby town of Jabiru consistently reveals very high numbers of pest and disease carrying mosquito species, generally in the post wet season and dry season months of April to August, and during a short period of a few weeks in the mid wet season. Low to moderate numbers of pest and disease carrying mosquito species are also encountered during most other months of the year. The presence of extended periods of high mosquito numbers translates to a significant potential for mosquito borne disease transmission in the Jabiru locality.The following report presents the results of brief field investigations in September and December 2005, a critical review of the nature and extent of natural mosquito breeding sites likely to affect Ranger Mine, outlines potential breeding sites at the mine site, outlines the adult mosquito and ovitrap program, and provides recommendations on how to manage potential mosquito issues at the mine site.

The efficacy of maximum label rates of bifenthrin applications to dry tires to prevent Aedes mosquito breeding was investigated through field colonisation and field bioassay trials. The effect of tires situated in shaded and unshaded locations was also investigated. Aedes notoscriptus and Culex quinquefasciatus larvae were the most abundant species present in the field colonisation trial. Colonisation of tires by Ae. notoscriptus larvae occurred significantly sooner in shaded compared with unshaded locations (P = 0.002), and bifenthrin applications in shaded tires only prevented colonisation for 2.5 weeks. Aedes notoscriptus larvae were not found in the unshaded tires until week 9. Culex quinquefasciatus colonised treated tires from the 2nd week in both shaded and unshaded treatments. In the bioassay, water from bifenthrin treated tires was found to kill 100% of Ae. notoscriptus for only 2.0 weeks in shaded and 2.2 weeks in unshaded treatments. Bifenthrin residual applications therefore cannot be relied upon for preventing mosquito breeding in tires for greater than 2 weeks.******** Note the American spelling of road vehicle tyres.