Controlling mosquitoes.

[arlanjoi]

wow i never thought of that

[DougF]

Originally Posted by Michaelangelica
There are heaps of newspaper links on community mosquito control in the USA for West Nile virus. All seem to involve spraying.
None say what spray is being used.
Does anyone know?

Well you asked for it and here it is. this is what is/was used in Florida.

Mosquito Information Website - Mosquito Management - Integrated Mosquito Management (IMM)

MOSQUITO CONTROL INSECTICIDES: PAST AND PRESENT
The synthetic pesticides used for mosquito control over the years have varied greatly in structure, toxicity, persistence, and environmental impact. These chemicals include the following: Organochlorines -- Today, no organochlorine pesticides are used for mosquito control in Florida. However, methoxychlor is still labeled for mosquito control use. Some organochlorines that were formerly used for mosquito control because of their high arthropod toxicity included DDT, BHC, chlordane, heptachlor, aldrin, and dieldrin. Organochlorines are relatively non-soluble in water and very persistent in soils; they bioaccumulate in fat and other lipids (lipophilic). Largely, it was these lipophilic properties that resulted in organochlorines no longer being labeled for use in the U.S. Organochlorines continue to be used for agricultural and mosquito control in developing countries. Many soils and rivers are still contaminated with residues of the most persistent of these compounds (i.e., DDT, endrin, dieldrin) (White & Krynitsky 1986), and they continued to be detected in wildlife a decade ago (Risebrough 1986).

Organophosphates (OP) -- Although OPs are generally less persistent than organochlorines, some have higher acute toxicities, both for mammals and other organisms (Pimentel & Lehman 1993). Currently recommended OP compounds are the adulticides malathion, fenthion and naled and the larvicide temephos. These compounds have relatively low mammalian toxicity and most usually break down rapidly; however, some breakdown products are also toxic.

Pyrethroids -- Pyrethroid insecticides are based on the chemical structure of a group of naturally occurring compounds, pyrethrums, derived from a flower native to Africa. Products extracted from these flowers have been used for thousands of years and are still used today but are extremely expensive. Artificially created pyrethroids used today in Florida for mosquito control are resmethrin, permethrin, and sumithrin. Synthetic pyrethroids are more persistent than natural pyrethrums and in a few cases are more persistent than OPs. Pyrethroids are broad-spectrum toxicants that are very toxic to fish, aquatic organisms and most other cold-blooded animals. Due to their high and broad range of toxicity to insects, they may affect beneficial species, thereby lessening natural controls, and for some pests may actually increase the need for further chemical control (Edwards 1993). However, to date, a need for increased chemical control because of pyrethroid use for mosquito control has not been demonstrated.

Carbamates -- No carbamates are currently used for mosquito control in Florida. The only carbamate formerly used for Florida mosquito control was propoxur. Carbamates are broadspectrum, tend to be more persistent than organophosphates in soil, and thus have the potential for considerable environmental impact (Edwards 1993).

Insect Growth Regulators (IGR) -- IGRs interfere with insect development typically resulting in larval or pupal mortality. For more than 20 years, the insect growth regulator methoprene (Altosid®) has been a widely used mosquito larvicide in Florida and elsewhere in the world. Methoprene is specific to immature insect larvae, especially dipterans, which include mosquitoes. Methoprene has extremely low mammalian toxicity. Diflubenzuron (Dimilin®), a chitin inhibitor, has much broader non-target impacts than methoprene, especially on marine and freshwater arthropods such as shrimp and crabs. Therefore, Dimilin is severely restricted to only certain allowable sites. Due to the potential for non-target impacts, it is not widely used.

Biologicals -- Bacillus thuringiensis israelensis (Bti) and B. sphaericus (Bs) are both bacterial larvicides (acting as stomach poisons) that are quite specific to mosquito larvae and a few other aquatic dipterans. Bti is used worldwide. Bs is newly labeled and only effective in freshwater habitats. Both are non-toxic to mammals and exhibit few or no non-target effects.

I can get more info you like.

[Star30]

Sorry Boerseun, I didn't see your last post until after I submitted mine.

Good point.

[Michaelangelica]

Originally Posted by Boerseun

One at a time, or the whole company at once? Er...

Co
Stop even thinking about bringing back DDT. Malaria isn't as bad as they make it out to be. What is bad, is the lack of proper identification mechanisms for the disease, and medicine. If, for instance, a little urine test strip can be manufactured that can test for malaria, and access to medicine can be arranged, then I suppose it'll just be "one of those things". You wake up with the shivers, you go pee on a little stick, you see you've got malaria, you swig a pill, you go back to bed. End of story. Distributing DDT all over the world will be at least as expensive as distributing meds.

Lasting effects? Not really. But my liver and kidneys look like swiss cheese, and will give me all the hell when I'm a few decades older, I guess.

But it only looks like swiss cheese because of late identification.

Malaria is by no means a terminal disease. What's killing people in the Third World is not malaria mozzies, but the lack of timely treatment.

the lack of timely treatment.[
Any suggestions?

[Michaelangelica]

Mosquitoes and Wetlands

There is a public perception that wetlands are breeding grounds for mosquitoes.

While nearly any open water can be a breeding ground for mosquitoes, research shows that properly designed and managed wetlands with balanced ecosystems and natural predators will control mosquito larvae as part of the natural food chain.

Melbourne Water is committed to ensuring that its wetlands are designed and managed to minimise the presence of mosquitoes.
Mosquitoes

There are more than 250 species of mosquitoes found in Australia, but only a few of these bite humans.

Mosquitoes like still, protected water systems, such as household swimming pools or other shallow water bodies.

Adult mosquitoes have a very short lifespan (from seven days to a month). However, eggs may remain dormant for up to one year, hatching when flooded with water.
. . .

Melbourne Water : Publications : Fact Sheets : Drainage : Mosquitoes and Wetlands

[DougF]

these are some links I thought you might fine interesting.

Bloodfed Culex annulirostris, the major vector of arboviruses in inland regions of Australia.

Mosquito photos



What you can do to help 'Stop the Bite':

Mosquito Control

The following are steps you can take to help 'Stop the Bite' from occurring in your backyard:

Trash should be placed in a garbage can with a lid. Buckets, cans and other small containers are favored breeding grounds for many mosquito species.
Unused wading pools should be turned over or stored in a dry place to avoid breeding mosquitoes.
Plastic tarps can trap small pockets of water that will breed mosquitoes. They should be checked weekly and any water dumped.
Bird baths should be cleaned and filled with fresh water at least once a week.
Gutters should be cleaned regularly, especially in the spring and fall when leaves and other debris can quickly clog them.
Flower pot drip trays should be inspected often to check for developing mosquito larvae.
Swimming pools must be maintained at the proper chlorine level throughout the summer season. Pool covers that collect water should be drained, flushed regularly or treated with chlorine to stop mosquito breeding. Abandoned pools should be taken down (for above ground pools) or filled (inground).
Old tires should be brought to an automotive store that can properly dispose of them. In fact, tires are the favorite breeding grounds for many of the mosquito species that transmit various diseases to humans throughout the world!


Mosquitoes breed faster when temperatures are high. Low temperatures and low humidity cause slow breeding and higher mortality rates.

Mosquito Breeding

[Michaelangelica]

interesting links

Mosquito Eating (Larvivorous) Fish

Hypseliotris compressa
The Empire Gudgeon, Hypseliotris compressa. A native fish, found in freshwater to brackish esturaries in the coastal drainage systems of the northern 2/3 of Australia. Approx. 9-10cm in length.
Pseudomugil signifer
The Pacific Blue-Eye, Pseudomugil signifer. Native to the east coast of Australia and found in fast flowing streams and brackish esturaries from Cooktown in Qld to southern NSW. Approx. 2-2.5 cm in length.

Gambusia holbrooki
The mosquito fish, Gambusia holbrooki. This imported species has become a major pest in waterways in most eastern states of Australia and is also found in parts of NT and WA. It inhabits both inland and coastal basins as well as brackish waters. Approx. 2-2.5 cm in length.

Mosquito photos

How many species of mosquitoes are there?
In Australia there are around 400 species but only approximately 10 are commonly abundant and represent a serious pest threat because of their nuisance biting or their ability to transmit disease.

So when we kill them all, what are we doing to the ecosystem?

Tripteroides magnesiana: (NT, QLD) a small attractive tropical mosquito which breeds in treeholes. The adults will bite humans although it is not known to transmit any agent of disease.
Mosquitoes of Australia

Mosquito Attractants
. . .unwashed naked children were more attractive to An. gambiae, An. funestus and An. pharoensis than naked children who had washed.
Dirty clothes in a hut attracted more mosquitoes than an empty hut.

Individual variation in attractiveness to mosquitoes was shown conclusively by Khan (1965), who was able to isolate 1 person very attractive and 3 people very unattractive to Ae. aegypti by observing both bloodfeeding and probing reponses.

Acree (1968) attributed differences in attractivity to the amount of lactic acid produced by the subject.
Males were more attractive than females and babies are not very attractive compared with men

Many substances have been tested as possible mosquito attractants. Rudolfs (1922) tested numerous substances using an apparatus with two chambers and a connecting glass tube. The following table shows a partial list of his results (only positive responses are included in the following table:

Substance Attractive Fed cold Fed warm
Alanine (crystals) Y
Ammonia Y
Beef Boullion Y
Cholesterol Y X
Cystine X
Glutamic Acid X X
Glycerin X X
Hemoglobin Y X X
Oleic Acid and Benzoic Acid X X
Peptone Y X X
Phenylalanine Y X X
Sugar solution X
Tyrosine X
Urine X X
Vaseline Y X X

Brown (1951) found both diethyl ether and gasoline to be significantly attractive to mosquitoes.

CO2

Gillies (1980) reviewed the effects of CO2 on the host-seeking response and concluded that the role of CO2 is still poorly understood
Several workers have been unable to show a response to CO2.

Lactic acid
Acree et al. (1968) identified lactic acid as a mosquito attractant after it was isolated from human arms through thin-layer chromatography. They found that the L isomer of lactic acid was 5 times as attractive as the D isomer. In addition, they considered CO2 essential for lactic acid to have an effect on mosquito attraction

Octenol
1-octen-3-ol (octenol) is an ingredient in the "synthetic ox odor" used to attract tsetse flies. Octenol has been shown to attract more Aedes taeniorhynchus, Anopheles spp. and Wyeomyia mitchellii mosquitoes when used together with CO2, though each attractant is capable of attracting mosquitoes on its own

Some others here Mosquito Host-Seeking: a Partial Review
Same page

Light
Seaton and Lumsden (1941) found that illumination of 0.5 meter-candles reduced the number of mosquitoes taking a blood meal by 50% below the number that fed in the dark.

[CraigD]

Originally Posted by Michaelangelica

So when we kill them all, what are we doing to the ecosystem?

Given the seeming impossibility of killing all the mosquitoes in any locale, I don’t think very many people have ever asked this excellent, if hypothetical, question. Given advances in bioscience, and the possibility that they might allow the creation of some sort of species-specific pathogen that actually could make the whole family or superfamily of mosquito-ish flies extinct, the question may not be forever a hypothetical one.

AFAIK, all of the several dozen species comprising Mosquito family (Culicidae) are nectar-feeders, so I’d guess their extinction might be trouble – perhaps extinction-level – for whatever sort of plants they, and nearly no other – insect feeds on, that depends on insects to spread their pollen.

Most Mosquito nymphs (larvae) eat microscopic plants and animals in the water, so their extinction might result in over-population of these plants and animals. Since ponds and other mosquito-prone bodies of water that have had 100% of their mosquito nymphs eradicated (not that hard, if the pond is well-defined, like an ornamental pool, and you’re diligent, and have a bit of light oil on hand) don’t appear to undergo any sort of small-scale ecological catastrophe, I don’t think this scenario too likely.

Many fishes (such as the ones Michaelangelica pictured) eat mosquito nymphs, so some of those species could be endangered, especially if they’ve specialized to eating little but mosquito nymphs. Compared to insect, however, most fishes have more flexible diets, so I suspect most of these fishes would at worst decline in population, not go extinct.

If the wiper-outer pathogen was a little too specific, and killed only some of the mosquito species, the ecosystem effect might be to increase the number of remaining mosquito species due to reduced competition, or wiping out the few mosquito species that prey on other mosquito species. If it was a little to general, and killed species several steps up the genetic tree, their beneficial effects lost. A few of those eat such things as tree-infecting mosses and algae, so something like a tree-disease epidemic might result.

The most obvious impact of wiping out all mosquitoes, however, would be that they’d no longer spread disease to human beings and other animals. Though this seems nothing but good, disease biology can be a tricky. Possibly the elimination of mosquito born diseases would result in a weakening of human and animal immune systems, making them susceptible to more severe diseases infections and epidemics.

A less obvious impact would be that areas that are now unattractive for human population due to a high rate of mosquito-born disease would become attractive. Rapid development of these areas could upset the ecosystems of these areas in the many ways rapid human development can upset ecosystems.

On the long term, there are a number of more and less wild theories that suggest that evolution depends a lot on genetic information carried by benign and disease-causing viruses. Cutting a major disease vector out of the ecosystem could, therefore, have a long-term effect on human and animal evolution. My hunch is this scenario is not much cause for concern, because ecosystems seem to be robust and adaptive, tolerating the extinction of even wide ranges of species.

In short, the benefit of wiping out mosquitoes – which, for millions of people each year, (including our own boerseun!), is literally a matter of life and death, seems greater than the risk to the ecosystem – though, as with everything biological, knowing more about the risk can’t be anything but a good thing.

[Michaelangelica]

[QUOTE]

Originally Posted by CraigD

Given the seeming impossibility of killing all the mosquitoes in any locale, I don’t think very many people have ever asked this excellent, if hypothetical, question.

Have you seen the Florida Air Force used for spaying the state with orthophosphates?
This is only one way (of many) of spraying the State.
In 1996, organized MCDs in Florida listed the following aircraft used for adulticidingchucking pesticide about from a great hight)

Fixed-Wing Aircraft

12 Douglas DC-3/C-47

3 Beech 18/C-45

1 Beech King Air C-90

1 Beech Queen Air

1 Beech Twin Bonanza

2 Piper Aztec

4 Cessna 337

Helicopters

2 BellUH-1B

9 Hughes/MD 500 C, D & E

2 Bell 206

3 Bell 47

4 Hughes 269 A, B & C

Given advances in bioscience,

there are some studies on making sterile males etc

AFAIK, all of the several dozen species comprising Mosquito family (Culicidae) are nectar-feeders, so I’d guess their extinction might be trouble – perhaps extinction-level – for whatever sort of plants they, and nearly no other – insect feeds on, that depends on insects to spread their pollen.

Yes I think it is unfortunate that mosquito=bad when very few mosquitoes bite humans and even fewer species transmit pathogens/disease.
If 1% of Kindergarden kids bite should they all be killed?

Most Mosquito nymphs (larvae) eat microscopic plants and animals in the water, so their extinction might result in over-population of these plants and animals. . . I don’t think this scenario too likely.

the truth is we don't know. Very little work seems to be being done on the possibility of mosquitoes having "good" ecosystem out comes

so I suspect most of these fishes would at worst decline in population, not go extinct.

Well the sprays like orthophosphates don't help. They are mostly (80%+) very toxic to fish and phytoplankton. Synthetic pyrethroids are also toxic to fish.

The most obvious impact of wiping out all mosquitoes, however, would be that they’d no longer spread disease to human beings and other animals.

No, just certain mosquitoes

Though this seems nothing but good, disease biology can be a tricky. Possibly the elimination of mosquito born diseases would result in a weakening of human and animal immune systems, making them susceptible to more severe diseases infections and epidemics.

A long bow, but you never know.

A less obvious impact would be that areas that are now unattractive for human population due to a high rate of mosquito-born disease would become attractive. Rapid development of these areas could upset the ecosystems of these areas in the many ways rapid human development can upset ecosystems

.
We drained swamps because we need more agricultural land land and fewer mosquitoes.
We now discovering that this was a mistake and many wetlands have important ecological roles in the system.

My hunch is this scenario is not much cause for concern, because ecosystems seem to be robust and adaptive, tolerating the extinction of even wide ranges of species.

True , so far, but now ecosystems are under unprecedented attack from all quarters.

In short, the benefit of wiping out mosquitoes – which, for millions of people each year, (including our own boerseun!), is literally a matter of life and death, seems greater than the risk to the ecosystem – though, as with everything biological, knowing more about the risk can’t be anything but a good thing.

Agreed, we know too little.
I also think we need to be a little more specific and targeted about our "War on Mossies" not the massive spraying of all varieties of mosquito like that in the USA.
(I think Florida does it to help their tourism industry.-
I wonder if the Tourists appreciate this - and what their reaction would be if they knew the full extent of pesticide use?)

[Star30]

No, I don't think I would want to be sprayed (even unintentionaly per say)with insecticide at any time especially not on holiday. When I think of going to Florida I think of beautiful ocean water.
The good thing, Florida counties do attempt mosquito control by budgeting for application of mosquito eating fish as michaelangelica nicely posted with #17 above.