Frequently asked questions

1. How fast can mosquitoes fly?
2. How far can mosquitoes fly?
3. How much do they weigh?
4. How much blood does a mosquito take in a meal?
5. Why do mosquitoes feed on blood?
6. What good do mosquitoes do?
7. How long do mosquitoes live?
8. If mosquitoes were eradicated, how would this affect the ecosystem?
9. How high do mosquitoes fly?
10. Can mosquitoes transmit AIDS?
11. What attracts mosquitoes to me?
12. How do mosquitoes get into my house?
13. What can homeowners do to reduce mosquito bites?
14. Are backyard misting systems effective?
15. Do Bug-Zappers Work?
16. Do Ultrasonic devices work?
17. Do mosquito traps work?
18. Do bats serve as an effective mosquito control?

How fast can mosquitoes fly?

Depending upon the species, mosquitoes can fly at about 1.5 to 3 km per hour.

How far can mosquitoes fly?

Mosquito species preferring to breed around the house, like the Dengue Mosquito, have limited flight ranges of about 500 metres. Most species have flight ranges of 5-10 km. The undisputed champions, though, are the saltmarsh breeders - having been known to migrate up to 50 km in exceptional circumstances, although 10 to 30 km is much more common when hosts are scarce. When caught up in updrafts that direct them into winds high above the ground, mosquitoes can be carried great distances.

How much do they weigh?

Smaller species found around houses commonly weigh about 2.5 milligrams. Our largest species weigh in at a whopping 10 milligrams.

How much blood does a mosquito take in a meal?

When feeding to repletion, mosquitoes imbibe anywhere from 0.001 to 0.01 millilitre.

Why do mosquitoes feed on blood?

Female mosquitoes imbibe blood so that their eggs can mature prior to laying. It serves no nourishment function. Males do not take blood meals at all. In order to obtain energy, both male and female mosquitoes feed upon plant nectars - much in the same manner as honeybees.

What good do mosquitoes do?

Mosquitoes fill a variety of niches which nature provides. As such, placing a value on their existence is generally inappropriate. Although the fossil record is incomplete, they have been known from the Cretaceous Period (about 100 million years ago) in North America. Their adaptability has made them extraordinarily successful, with upwards of 2,700 species worldwide. Mosquitoes serve as food sources for a variety of organisms but are not crucial to any predator species.

How long do mosquitoes live?

Lifespan vary by species. Most adult female mosquitoes live 2-3 weeks.

If mosquitoes were eradicated, how would this affect the ecosystem?

Given that nature abhors a vacuum, other species will fill the niches vacated by the mosquitoes after an initial shuffling period of variable length.  Be advised, though, that species replacing mosquitoes may be even worse - it is extremely difficult to predict.  Mosquitoes' ability to adapt to changing environments would make them all but impossible to eradicate.

How high do mosquitoes fly?

In general, mosquitoes that bite humans prefer to fly at heights of less than 25 ft. Asian Tiger Mosquitoes have been found breeding in tree holes over 40 feet above ground. In Singapore, they have been found in apartments 21 stories above ground. Mosquitoes have been found breeding up to 8,000 feet in the Himalayas and 2000 feet underground in mines in India.

Can mosquitoes transmit AIDS?

Many studies have been conducted on this issue and there has never been a successful transfer of the virus from an infected source to another host by blood feeding insects under experimental conditions. The experts have concluded that the insects are not capable of such transmission. Many biological reasons would lead one to this same conclusion, but the extensive experimental studies are the most powerful evidence for the conclusion.
HIV DOES NOT replicate in mosquitoes. Thus, mosquitoes cannot be a biological vector as they are for malaria, yellow fever, or dengue. In fact, mosquitoes digest the virus that causes AIDS.
There is no possibility of mechanical transmission (i.e., flying contaminated syringes); even though we all know, that HIV can be transmitted by dirty needles. However, the amount of "blood" on a mosquitoes' mouthparts is tiny compared to what is found on a "dirty" needle. Thus, the risk is proportionally smaller. Calculations based on the mechanical transmission of anthrax and Rift Valley fever virus, both of which produce very high titres in blood, unlike HIV, showed that it would take about 10,000,000 mosquitoes that first fed on a person with AIDS and then continued feeding on a susceptible person to get one transmission.
Mosquitoes are not flying hypodermic needles. Mosquitoes regurgitate saliva into the bite wound (the normal route for disease transmission) through a separate tube from that through which it imbibes blood.

What attracts mosquitoes to me?

Why some people seem to be more attractive than others to mosquitoes is the subject of much repellent (and attractant for traps) research being conducted nationwide. Carbon dioxide is the most universally recognized mosquito attractant and draws mosquitoes from up to 35 meters. When female mosquitoes sense carbon dioxide they usually adopt a zigzagging flight path within the plume to locate its source. Once in the general vicinity of a potential host, other cues predominate, including body odours (sweat, lactic acid, etc.) and heat. Odours produced by skin microflora also play a part in inducing the mosquito to land. Over 350 compounds have been isolated from odours produced by human skin. Either singly or in combination, many of these compounds may be attractants - and many may be repellents. As you can see, the situation is complicated and will require many years of testing before it can be sorted out. Visual stimuli, such as movement, also factor into host-seeking. What can be safely stated, though, is that ingestion of garlic, vitamin B12 and other systemics has been proven in controlled laboratory studies to have no impact on mosquito biting. Conversely, eating bananas did not attract mosquitoes as the myth suggests, but wearing perfumes does. People drinking beer have been shown to be more attractive to mosquitoes. Limburger cheese has also been found to be attractive. Scientists have theorized that this may explain the attractancy some mosquitoes find for human feet.

How do mosquitoes get into my house?

Mosquitoes are singularly adept at entering houses through any portal available, be it through broken window or door screens, attic soffits or through bathroom exhaust vents. A favourite resting spot is the garage, so take care to keep resting female mosquitoes from coming into the house through the garage.

What can homeowners do to reduce mosquito bites?

If possible, schedule your activities to avoid the times when mosquitoes are most active - usually dawn and dusk. You should also dress in light, loose-fitting clothing. If you have a deck, light it using yellow "Bug Lights". These lights are not repellent, per se, but do not attract mosquitoes like other incandescent lights. Mosquitoes are relatively weak fliers, so placing a large fan on your deck can provide a low-tech solution. Citronella candles have a mild repellent effect, but do not offer significantly more protection than other candles producing smoke.

Are backyard misting systems effective?

Scheduled sprays used by these misters may needlessly broadcast pesticides into the environment, affecting mosquitoes and non-target insects alike. Modern mosquito control strategies emphasize an integrated approach, based upon a profound knowledge of the target, so that its’ various vulnerabilities can be exploited by the many tools we've developed for that purpose. Effective mosquito control requires continual survey of adult mosquito densities to determine if certain triggers for control are met. This reduces the use of adulticides to only those times when they are required.

Do Bug-Zappers Work?

Black light insect electrocution devices (Bug Zappers, etc.) are purchased in huge quantities by homeowners due to their demonstrated ability to attract and kill thousands of insects over a 24 hr. period. But do they really control pest insects? Bug zappers do indeed kill some mosquitoes. However, the only two controlled studies conducted to date by independent investigators at the University of Notre Dame showed that mosquitoes comprised merely 4.1% and 6.4% respectively of the daily catch over an entire season. Even more important was the finding in both studies that there was no significant difference in the number of mosquitoes found in yards with or without bug zappers. What is particularly disconcerting, however, is the number of non-pest insects that comprise the vast majority of trap catch. Many of these insects are beneficial predators on other insect pests. They in turn constitute a major part of the diet of many songbirds. Indeed, reduced numbers of moth and beetle prey species have contributed significantly to the decline of songbird populations in many affluent suburbs. Insect electrocution devices undoubtedly bear some responsibility for this phenomenon. Mosquitoes continue to be more attracted to humans than to the devices. One study conducted in homeowners' backyards showed that of the insects killed by these devices, only 0.13% were female mosquitoes

Do Ultrasonic devices work?

At least 10 studies in the past 15 years have unanimously denounced ultrasonic devices as having no repellency value whatsoever. Yet, consumers flock in droves to hardware stores to purchase these contraptions. Why? The discovery that mosquitoes locate mates in mating swarms via wing beat frequency generated a great deal of research into ultrasound as a potential source of environmentally-friendly control. Yet, all attempts to affect mosquito behaviour by ultrasound have fizzled, despite enormous amounts of money spent upon research and development. To be sure, the clever, high-tech, and imperceptible (by humans) use of ultrasound proved to be an exceedingly effective marketing tool for the repeller manufacturers. Homeowners were urged to buy ultrasonic repellers and the like to rid their houses of pests without the need to inhale "even one breath of poisonous spray". This appeal to the public's chemo phobia, while extremely effective in diverting attention away from proven preventive and control measures (and toward their repeller products), has undermined an unbiased review of the subject by consumers desperate for a clean, effective, nonchemical means of mosquito control. Unfortunately, no such miracle cure exists. A pioneering study testing five different ultrasonic devices against four mosquito species convincingly demonstrated that ultrasound in the 20-70 kHz range used by these devices had no effect on reorienting flight by female mosquitoes either toward or away from human subjects. Additional tests have shown that sound generators capable of a wide range of frequencies were also ineffective in repelling mosquitoes. The fact is that these devices just do not work - marketing claims to the contrary.

Do mosquito traps work?

An enormous amount of consumer interest has been generated by the marketing of new devices designed to attract, then either trap or kill, mosquitoes. The general idea is to reduce the number of questing mosquitoes that would otherwise be afflicting the homeowner. Many products even claim to significantly reduce or even collapse local mosquito populations by decreasing the number of egg-laying females through their capture. All of these traps utilize some form of attractant that lures the host-seeking female mosquitoes to a capture or killing device. In some cases, mosquitoes are captured via an impellor fan that suctions them into a net, where they desiccate while other trapping systems use a sticky surface to which the mosquitoes adhere when they land. Still others utilize an electric grid to electrocute mosquitoes drawn into contact. These are not set-and-forget devices. Each requires some level of maintenance, i.e. propane tanks need replacement, capture nets need emptying, adhesive boards require replacement and grids require cleaning to ensure their continued effectiveness, particularly in areas of high catch. The process of a mosquito questing for a blood meal involves a complex, interconnected cascade of behaviours, each probably having its own cues, be they visual, thermal, or olfactory. The complexity of these questing behaviours may account for the bewildering variations in trapping efficiency noted for certain species of mosquitoes at different times, seasons and places. With over 260 species of mosquitoes currently recognized in Australia, this is no small issue and will require many years before research can provide a clarification. There is some anecdotal evidence that these baited traps, indeed, capture more females of some species than others, depending, to some extent, on the concentration of carbon dioxide emitted and the mosquito species present. There may also be seasonal and circadian variables that affect mosquito responses to certain attractants. Nonetheless, these devices will trap and kill measurable numbers of mosquitoes. Whether this will produce a noticeable reduction in the mosquito population in each case will depend upon a number of factors, e.g. individual tolerance level, absolute mosquito population size, proximity, size and type of breeding habitat producing re-infestation, wind velocity and direction, and species of mosquito present, and others. Thus, the homeowner must still use repellents and practice source reduction methods as adjuncts to realize any measure of relief. Please be cautioned against putting too much faith in traps as your sole means of control. These traps represent an evolving technology that is a most welcome addition to our mosquito control armamentarium. Their potential is great, but shouldn't be overestimated. It's highly unlikely that these devices, whatever their improvements, will ever fully supplant organized community-wide mosquito control programs, for there is no single silver bullet that will prove to be the ultimate answer to mosquito problems.

Do bats serve as an effective mosquito control?

Recently the public has shown increased interest in the value of insectivorous species of bats in controlling mosquitoes. Although untested lately, this is not a new idea. During the 1920's several bat towers were constructed near San Antonio, Texas, in order to help control malarial mosquitoes. Mosquito populations were not affected and the project was discontinued. Bats in temperate areas of the world are almost exclusively insectivorous. Food items identified in their diet are primarily beetles, wasps, and moths. Mosquitoes have comprised less than 1% of gut contents of wild caught bats in all studies to date. Bats tend to be opportunistic feeders. They do not appear to specialize on particular types of insects, but will feed on whatever food source presents itself. Large, concentrated populations of mosquitoes could provide adequate nutrition in the absence of alternative food. However, a moth provides much more nutritional value per capture than a mosquito. M.D. Tuttle, a world authority on bats, is often quoted for his anecdotal report that bats effectively controlled mosquito populations at a popular resort in New York State. While there is no doubt that bats have probably played a visible, if not prominent, role in reducing the mosquito problems in many areas, the natural abatement of mosquito populations is an extremely complex process to study, comprising poorly known ecological relationships. Tuttle attempts to underscore the bats role by citing an experiment in which bats released into a laboratory room filled with mosquitoes caught up to 10 mosquitoes per minute. He extrapolated this value to 600 mosquitoes per hour. Thus, a colony of 500 bats could consume over a quarter of a million mosquitoes per hour. Impressive numbers indeed, but singularly unrealistic when based upon a study where bats were confined in a room with mosquitoes as their only food source. There is no question that bats eat mosquitoes, but to utilize them as the sole measure of control would be folly indeed, particularly considering the capacity of both mosquitoes and bats to transmit diseases.