Lice
- these are creatures that live absolutely anywhere in the world. life expectancy is about a month. These are unique arthropod insects, whose life is directly related to the human body and blood. Getting rid of these parasites is problematic, since they reproduce at lightning speed, and their larvae are quite difficult to remove and getting rid of them is also problematic even with modern drugs. Once upon a time there was a legend that people with lice would be rich and happy. But it’s hard to believe, since the word “lice” immediately scares away and instills fear. People who have lice try in every possible way to hide this fact so as not to scare off those around them. It is believed that these parasites live only in human hair and have no specific place of residence. But this is far from true. In the article you will learn the whole truth about these insects (where they come from, how to fight them and what danger they pose to humans and their environment).
What do lice look like?
These parasites are microscopically small, barely reaching five millimeters in size. They have a clearly defined abdomen, but the head, on the contrary, is very small. They practically do not see, they keep their orientation solely by smell. Amazing fact: lice have wings, but they are also small in size and therefore they do not fly.
The oral apparatus of lice is of the piercing-sucking type with a proboscis and two needles. When a louse begins to feed on blood, its proboscis sticks out and attaches itself to a specific puncture site in the skin. When a bite occurs, saliva is released, which prevents blood clotting and subsequently causes itching on the human skin. Important point. Lice cannot completely penetrate human skin; only the proboscis gets there, which pumps out blood. They linger on the hair thanks to three pairs of legs, at the ends of which there are claws. Lice move at a speed of 20 centimeters per minute. It’s scary, but lice attach their nits, that is, larvae, to the hair on a sticky substance. With large fertilization, the female can lay several hundred eggs at a time. Hatching time is about sixteen days.
What are they needed for?
Why did lice appear? Why do nature need them at all? Surely this question was asked by every person who happened to encounter them. All living beings are useful in some way. Every animal and insect plays some role in the biosphere of the planet. What about lice? Do lice have any significance in nature?
There is an assumption that these parasites were included in the food chain at the beginning of their existence. They may have been larger and more nutritious than they are now. Over time, they became smaller and at one point fell out of the social life of the planet. Now they are just parasites. Harmful and certainly useless to anyone.
Lice are the source of many unpleasant symptoms, the main one being itching
Life cycle of lice
In general, lice are quite tenacious.
They can adapt to any environment, be it hot or cold. Also, together with a person, they can stay under water for a long time. Surprisingly, nits (lice larvae) are much more tenacious than the lice themselves; even some chemicals do not kill them. They feed exclusively on human blood. When bitten, a person only feels itching and cannot even think that at that very moment a louse is biting him. Life expectancy is about 28 days. During this time, the female lays more than 200 eggs, and this carousel never ends.
When a person begins to fight lice, he pays close attention to this moment. That is why the fight against parasites takes about a month to overcome both adults and their offspring.
Development of pediculosis
After reaching a new host, the adult leads an active life, feeding and reproducing. Every 4 hours, this blood-sucking parasite drinks its portion of blood. The nymph even feeds every 2 hours. A little blood is consumed and the bite itself does not cause pain. But due to the substance contained in saliva, irritation appears on the skin, causing itching.
As the number of bites increases, the irritation becomes stronger, and accordingly, the symptoms of lice become more pronounced. When pediculosis develops, its signs include:
- presence of severe itching;
- the appearance of poorly healing scratches on the scalp due to a large number of bites;
- an infection can get into the wound, which makes the skin damage more significant;
- with an active process, it is possible for hair to stick together with serous-purulent exudate and the appearance of a so-called “tangle”;
- Due to constant itching, a person becomes more irritable.
At first, after the appearance of parasites, you may not notice their presence. Not everyone attaches importance to minor skin irritation from a few bites. But as their number increases, the development of pediculosis will be difficult to miss. Considering how quickly lice lay eggs and how quickly they grow into adults, it will take no more than 2-3 weeks before the parasites are detected even on an unsuspecting person.
Lice can cause serious harm to a person's health if they become infected. In this article you can find out more about why they are dangerous.
How do lice reproduce?
In order for a female to become fertilized, one mating is enough and after that a “repeat procedure” is no longer required.
If one fertilized female gets on a person’s hair, then after a few days about a hundred nits will live on the hair. A few hours after fertilization, the female begins to gradually lay eggs on the human hair and tightly glue them to this same hair.
After a week or a week and a half, the upper lid of the egg bursts and a young nymph emerges from there. She immediately begins to suck blood, which leads to her reaching full maturity eight days later. If suddenly the nit does not find a food source, then within a day it will completely die from dehydration. Now imagine that hundreds of these nits live in your hair, constantly sucking your blood.
Do nits jump?
So, nits are lice eggs. It’s worth saying right away that at this stage of development, individuals are completely deprived of the ability to move. They don't jump, fly, run or even crawl.
Females attach the nit to the hair, using an adhesive substance, thanks to which it is securely attached until maturity. After maturation, the young individual leaves the shell, and it remains on a thread.
In the nit stage, individuals do not require nutrition; in addition, their shell reliably protects them from the effects of all negative factors. They easily tolerate temperature changes, and if nits find themselves in unfavorable conditions for further development and maturation, they hibernate. During hibernation, the formation of the parasite stops; as soon as conditions become favorable, they continue development.
Lice diet
As mentioned earlier, lice feed exclusively on human blood; their bodies are designed in such a way that only blood is available to them.
Some people believe that if there is a lack of blood, lice can feed on both dandruff and the hair itself. This is far from true. They simply cannot feed on hair. The frequency of blood suction occurs 5 times a day, every 2–3 hours. In one suction, a louse is capable of pumping up to 0.5 ml of blood from the human body. After complete saturation, lice are able to reproduce further.
Treatment
To destroy ectoparasites on the body of dogs, insecticides are used in the form of dusts, solutions, emulsions and aerosols. When choosing a drug, take into account the duration of its action and toxicity to the animal’s body. The effect of an insecticide depends not only on its form and quality, but also on the thoroughness of application to the skin of the animal.
All drugs have a stronger effect on the larvae, then on the adult forms, killing them, but do not have a detrimental effect on the eggs. In this regard, all treatments must be carried out at least twice: in the summer - after 10-12 days, in the winter - after 14-18 days. When using insecticides with a long residual effect, they are limited to a one-time treatment.
Dogs are washed with pet shampoo, which leads to the death of ectoparasites, cleansing of the skin and the disappearance of odor.
In the cold season, dusts of pyrethrum, 2% sevin, 3-5% chlorophos (10-30 g per animal) are used. During treatment (10-15 minutes), the animals are placed in a special bag with a purse-string suture to secure the upper part of the neck. It is recommended to carry out dust treatment outdoors or in a spacious, well-ventilated room. Make sure that the drug does not get into the feed. Persons carrying out processing must wear protective clothing, safety glasses and gauze masks.
They also offer for use a 0.75-1% aqueous solution of chlorophos, 0.5% aqueous emulsions of trichlorometaphos-3 and karbofos, 0.15% cyodrine emulsion, 0.25-0.5% suspension sevin, 0.5% ectobacterin suspension, 4% K soap emulsion, Akrodex aerosol and dermatosol.
How long do lice live and how do they die?
As mentioned earlier, a louse can live for 38 days.
At the same time, she can live without food for only 10 days, if there are comfortable conditions for her existence. If the air temperature is more than 45 degrees, only then will the lice begin to die. These insects can live for a couple of days in cold water and this is how they get onto the human body when swimming in a river or pool.
When a person is shaved bald, lice will not be able to survive, since they have nowhere to hide and they will not be able to stick their offspring. Consequently, they will be discovered and destroyed.
There are drugs that can deal with lice in a couple of doses. These drugs will be discussed below. For now, let's look at the types of lice.
- Head louse
. It lives exclusively on the human head, in the hair. - Pubic louse
. This type is based on the human genitals (armpits, eyebrows, beard - all those genitals where there is hair). - Body louse
. Habitat: clothes and linen. It also feeds exclusively on human blood.
Origin of the species and description
Photo: Louse
It is generally accepted that lice are descended from book lice (order Psocoptera). It is also recognized that chewing lice are related to sucking lice; some researchers believe that they evolved from offspring before division into species, others that they differed from species already parasitizing mammals. The origin of elephant lice is unclear.
Apart from lice eggs found in Baltic amber, there are no fossils that can provide information about the evolution of lice. However, their distribution is somewhat similar to the history of fossils.
The genus of chewing louse often has a number of species that are limited to a single bird species or a group of closely related birds, suggesting that the genus assigned to the order of birds was parasitized by an ancestral stock of chewing louse that diverged and evolved along with the divergence and evolution of its avian hosts .
Video: Louse
This relationship between host and parasite may shed some light on the relationship between the hosts themselves. Flamingos, which are usually housed with storks, are parasitized by three genera of sucking lice, found elsewhere only in ducks, geese and swans, and may therefore be more closely related to these birds than to storks. The louse closest to the human body louse is the chimpanzee louse, while in humans it is the gorilla pubic louse.
However, a number of factors have obscured the direct relationship between lice species and host species. The most important of these is secondary infestation, which is the emergence of lice species on a new and unrelated host. This could have occurred at any stage of host or parasite evolution, so that the subsequent divergence obscured all traces of the original host change.
The length of the flattened bodies of lice ranges from 0.33 to 11 mm, and they are whitish, yellow, brown or black. All bird species probably have chewing lice, and most mammals have chewing or sucking lice, or both.
Ways to get rid of parasites
Pediculosis is not able to resolve and go away on its own.
If the disease is not treated, then over time the number of lice will increase, the individuals will grow, which will significantly prevent the victim from feeling normal. There are two ways to combat nits - mechanical and chemical. But where would we be without folk recipes? This option is more related to the chemical method and will also be discussed in the article.
Mechanical methods
This includes methods such as: shaving bald, combing out parasites with a strong comb.
You can also apply thermal effects with a hair straightener or tongs. Not everyone likes a haircut, especially girls and women who are not ready to take such radical measures. And not all men will want to say goodbye to their haircut. These two methods must be combined, since it will not be enough to buy a product at the pharmacy and use only it. After the procedure, it will be necessary to comb out dead nits from the hair with a comb. The thing is that some drugs do not completely destroy nits; their shell reliably protects them from chemical exposure.
Also, in order to comb out all the nits, a regular curl of hair will not work. The comb should be strong, strong and with teeth that are located very close to each other.
Chemical methods
Currently, quite a lot of chemicals are produced to combat these pests. They differ in price, quality, consistency and method of application. So, let's look at the most effective ones:
- Shampoos.
Hygia, Lavinal. These brands are quite effective if used as written in the instructions. They are relatively inexpensive, but the results are guaranteed. There are also separate shampoos produced specifically for children. - Sprays.
They are more effective than shampoos, but they are more expensive, there is more hassle in carrying out the procedure, and, no less important, they are poorly washed off the head. Usually, a comb is included with the sprays. - Aerosols.
They are designed for processing clothing and bedding. There are quite a lot of brands, some simply use Dichlorvos. - Creams.
Less commonly found in stores and pharmacies, they are in no way inferior in effectiveness to sprays. - Combs.
They differ from ordinary combs and are intended only for combing out dead animals. Use in combination with sprays or shampoos. As an independent remedy, it will not give maximum effect.
Linen lice can be removed by thoroughly washing the laundry and then ironing it at high temperatures.
Prevention
To protect yourself from infection, it is recommended to adhere to the following rules:
- avoid close contact with infected people;
- refuse casual sexual contacts;
- use only your own household items - combs, hairpins, scarves, etc.;
- change clothes regularly and wash them at high temperatures;
- carefully examine the scalp of yourself and your child;
- use special repellents if necessary;
- Apply anti-lice shampoos in small quantities from time to time.
You should not perceive lice as unpleasant but harmless bugs that can only cause itching at the bite sites . These blood-sucking parasites can carry severe infectious diseases, provoke allergies and cause rough skin. Lice must be dealt with immediately as soon as insects or their metabolic products are noticed.
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Dog louse
Dog louse, like cat louse, are called lice only due to some external resemblance to these parasites. In fact, they are not lice, but lice-eaters and live exclusively on one type of animal, posing no danger to other animal species or to humans. Thus, a dog louse can live and parasitize only on a dog, and a cat louse only on a cat. Lice eaters differ from lice in that blood is not their only food. They consume the skin secretions of animals, pieces of its skin. Externally, lice eaters are similar to lice, but have a large head compared to the body.
Moose louse
The moose louse is the name given to the deer bloodsucker, a fly that is found primarily on artiodactyls of wild or domestic animals. It is called deer tick and moose fly. It is a flat, up to 4 mm long insect with wings. Young individuals, having hatched from the pupal stage, look for a large animal on which they can parasitize.
Having landed on the future owner, they shed their wings, find a pair and climb into the thickness of the undercoat. There they feed, reproduce, give birth to new individuals, which in the pupal stage fall to the ground and, having hatched, also fly away in search of shelter.
