efficient monitoring or surveillance is essential to prevent the spread and establishment of this species. in addition to the monitoring of ports, warehouses with imported plants, and stockpiles of tires, rest areas on highways and train stations should be monitored with appropriate methods. stagnant water removal the control of asian tiger mosquitoes begins with destroying the places where they lay their eggs, which are never far from where people are being bitten, since they are weak fliers, with only about a 180 m (650 ft) lifetime flying radius. puddles that last more than three days, sagging or plugged roof gutters, old tires holding water, litter, and any other possible containers or pools of standing water should be drained or removed. bird baths, inlets to sewers and drainage systems holding stagnant water, flower pots, standing flower vases, knotholes, and other crevices that can collect water should be filled with sand or fine gravel to prevent mosquitoes from laying their eggs in them. any standing water in pools, catchment basins, etc., that cannot be drained, or dumped, can be periodically treated with properly labeled insecticides or bacillus thuringiensis israelensis (bti), often formed into doughnut-shaped "mosquito dunks". bti produces toxins which are effective in killing larvae of mosquitoes and certain other dipterans, while having almost no effect on other organisms. bti preparations are readily available at farm, garden, and pool suppliers. flowing water will not be a breeding spot, and water that contains minnows is not usually a problem, because the fish eat the mosquito larvae. dragonflies dragonflies are also an excellent method of control. dragonfly larvae eat mosquito larvae in the water, and adults snatch adult mosquitoes as they fly. ovitraps in any case, an efficient surveillance is essential to monitor the presence of tiger mosquitoes and the effect of control programs. ovitraps are normally used for the monitoring of ae. albopictus. they are black water containers with floating styrofoam blocks or small wooden paddles that are in contact with the surface of the water. female tiger mosquitoes lay their eggs on these surfaces. through the identification of these eggs or of the larvae that hatch from these eggs in the laboratory, the presence and abundance of mosquito species can be estimated. versions of these traps with an adhesive film (sticky traps) that catch the egg-depositing mosquitoes make the analysis much easier and quicker, but are more complicated in terms of handling. the results of ovitraps are often variable and depend on the availability of alternative egg-depositing waters. due to this, it is best to use them in large numbers and in conjunction with other monitoring methods. to date, few effective traps for adult asian tiger mosquitoes are available. those traps that catch other species of mosquitoes do not catch tiger mosquitoes efficiently. a form of an ovitrap called a lethal ovitrap mimics the breeding site for ae. albopictus just like the monitoring tool, but it has the added benefit of containing chemicals that are toxic to the mosquitoes when they enter, but do not harm humans. these traps have had success in some countries to control aedes mosquito populations. a new trap type has now been shown to catch significant numbers of ae. albopictus. this device, with the help of a ventilator, produces an upward air current of ammonia, fatty acids, and lactic acids that takes a similar form and smell of a human body. with the addition of carbon dioxide, the efficacy of the trap is increased. this means a suitable tool is available for trapping adult tiger mosquitoes, and for example, examining the existence of viruses in the trapped mosquitoes. previously, the mosquitoes had to be collected from volunteers to be studied, which is ethically questionable, especially during epidemics. recent research also indicates this trap type may also have a use as a control tool; in a study in cesena, italy, the number of biting tiger mosquitoes was reduced in places where traps were installed. an amino acid substitution mutation – f1534c – is overwhelmingly the most common voltage-gated sodium channel in a. albopictus in singapore. this channel as the target of pyrethroids, is suspected to be a knockdown resistance (kdr) mutation, and that is the reason for its prevalence. public health benefits although the wolbachia infection is prevalent in arthropod species, especially the asian tiger mosquito, it is a useful mechanism for inhibiting the spread of dengue. ae. aegypti individuals, a close relative of ae. albopictus, with an artificial wolbachia infection, cannot transmit dengue, an infectious virus, but they can pass on the wolbachia infection to other populations. this could lead to many more discoveries in disease control for ae. albopictus and other mosquito species. in addition, due to the cytoplasmic incompatibility caused by wolbachia, the artificial infection of males can serve as a biological control as they are unable to reproduce successfully with uninfected females (unidirectional ci). when artificially infected males are unable to reproduce, the population size can be controlled, thereby reducing the transmission of the harmful disease of interest. artificial infection of males is achieved by the removal of cytoplasm from infected oocytes, which is then transferred into embryos prior to the blastoderm stage.