Posted by: lensweb | June 9, 2016

Rumble in the Jungle Part 1

Rumble in the jungle

“It has long been an axiom of mine that the little things are infinitely the most important” (Sherlock Holmes)

The higher temperatures and increased rainfall predicted for the UK by climate change models could mean more mosquitoes. Mosquitoes are more than a nuisance, they can carry disease and cause more human suffering than any other organism.  The female mosquito is the one that bites (males feed on flower nectar). She requires blood to produce eggs. Her mouthparts are constructed so that they pierce the skin, literally sucking the blood out. Her saliva lubricates the opening. It’s the saliva plus the injury to the skin that creates the stinging and irritation we associate with mosquito bites.

Mosquitoes home in on carbon dioxide trails and then use heat to find where blood is closest to the surface. Mosquitoes are visual hunters that search out prey by looking for moving profiles against the horizon. They are also attracted to naturally-occurring chemicals that are released as people breathe. These secondary attractants, can lure the insects to that one unlucky person.  The chemicals vary, but one is related to oestrogen, women are more often bitten by mosquitoes.  Mosquitoes can get drawn in by lactic acid, your reward for exercising, and the smell of stale sweat. Drinking beer makes a person more attractive to mosquitoes, it is not known why. Flushed with alcohol and vulnerable there is possibly something different about the skin chemistry or mosquitoes are attracted to an increase in sweat or an increased skin temperature.

How to avoid mosquito bites? Mosquitoes become most active, around dusk and dawn. Experts recommend staying indoors, but it is no good asking a wildlife watcher, a moth trapping, bat logging enthusiast to stay indoors at these times. Wildlife enthusiasts are safer on  windy days as mosquitoes are weak fliers, a strong breeze can render them unable to land. Experts recommend we follow the three “D’s”: Drain, dress properly and defend.

Drain any standing water around the house, cover water butts, remove leaves and change the water regularly in bird baths and paddling pools every five days, as it takes mosquitoes from five to 14 days to grow from egg, through an aquatic larval stage to adult

Dress properly Mosquitoes can and will, bite through tight-fitting clothing, so wear loose-fitting, light coloured clothing with long sleeves and pants. Dressed in dark colours you stand out against the horizon.

Defend using a known mosquito repellent. Originally developed for the military DEET Jungle Formula, is unrivaled in its ability to keep mosquitoes from biting. But there are concerns about toxicity, especially for young children.

Most natural remedies have not been proven effective. The army are rumoured to use Avon Skin-So-Soft. Some think that eating garlic could keep mosquitoes away. If you take garlic and squeeze it on your skin, that portion of your skin will be repellent to mosquitoes for about 20-40 minutes.  The smell could be worse than the itch and you’d be repellent to other people too.

Can vitamin B1 tablets make you a less tasty treat to the biting menaces? Probably not. There is no proven evidence that Thiamine could help reduce mosquito attraction.

Would bananas help? The predominant thinking is that bananas do make you more attractive (to mosquitoes). Yikes!  Of all the natural-based products, lemon eucalyptus is considered the most effective.

No insect repellent, even DEET, is one hundred per cent effective. To relieve itching, applying hot water (uncomfortable, but not scalding) for a few seconds relieves itching for an hour or more. Otherwise ask a pharmacist for advice.

There are 34 recorded mosquito species in the UK. Although most bite humans, the most common mosquito in Britain is Culex pipiens, which feeds on the blood of birds, not humans. Unlike the tropics, mosquitoes in this country are not currently known to transmit any infections. Climate change is predicted to bring wetter, warmer weather conditions in the UK , could provide ideal mosquito breeding conditions.

If the Asian Tiger mosquito (Aedes albopictus) arrives in the UK, it is likely to cause a significant biting nuisance. Suspected sightings occur every summer, but have always been identified as the endemic species Culiseta annulata. Public Health England (PHE) runs a collaborative nationwide mosquito surveillance project. The mosquito reporting system collates data on the distribution and ecology of all British mosquitoes and aims to

  • promote the surveillance of mosquitoes in the UK
  • understand the impact of mosquitoes and their biting nuisance on people
  • detect exotic mosquito species
  • improve our understanding of the public health risk posed by mosquitoes and mosquito-borne infections.

PHE relies upon members of the public, entomologists, researchers, ecology consultants, wildlife groups and other to submit mosquitoes to the scheme. Individuals and groups are invited to help in the development of the database on mosquito distributions. This can be done by submitting a photograph Email to mosquito@phe.gov.uk or by sending in any mosquitoes collected, along with details of:

  • date of collection
  • specific location (grid reference)
  • general location (nearest town or village)
  • local habitat (eg woodland, pasture)
  • contact details of the individual sending in the sample

Fresh specimens should be sent to Mosquito reporting, Medical entomology, Public Health England, Porton Down, Salisbury SP4 0JG with a completed mosquito reporting form

Specimens will be identified and PHE will reply by email.

PHE also run a network of mosquito traps to understand the population dynamics, status, distribution, abundance and seasonality of mosquitoes which are potential endemic vector species at key habitats and across regions. Mosquito traps are run for 2 weeks every month, from mid-April to mid-October, and samples are identified by PHE’s medical entomologists.

If you are interested in being involved with mosquito surveillance, emailmosquito@phe.gov.uk. All records are available from the National Biodiversity Network (NBN) Gateway for research and public use.

PHE is interested in receiving submissions from those people who may be impacted by mosquito nuisance biting, so let me tell you about the LENS visit to Hilton Gravel Pits last Monday………………

Marion Bryce 9 June 2016

Information and photograph from various internet sources


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