Why do we need mosquitoes, fleas and ticks

Polish cochineal was used to dye fabric red. It was heavily exported from Poland in the 14th-15th centuries. Whole barges packed with these insects sailed down the Vistula to Gdańsk, and from there they were distributed all over the world," says Marek Kozłowski, PhD, an ethologist and expert on insects.

TVP Dokument invites you to an eight-episode documentary series ”People and bees”

TVP WEEKLY: Spring is here, summer will soon come and with it we will start complaining about mosquitoes, ticks and other insects that do not make our lives more pleasant. Is that right?

It depends on your point of view and how you look at things. Often, unfortunately, we forget that we are, in a way, entangled in the whole web of interactions of nature, that is, living organisms. It can easily be proved that if it were not for insects, we would not exist on this Earth at all. After all, we are descended from animals that are insectivorous. Insects are also, as it were, small animals that have a very long history.

During this time, as far as biocoenoses [a biocenosis is a set of populations of plant and animal organisms and microorganisms belonging to different species, but related to each other by various interrelationships - ed.] on land - because let us remember that there are no insects in the oceans, they are somewhat replaced by crustaceans - insects, which are small and fast, have squeezed themselves into almost every crevice of the environment and live very well. They also make the environment function to a large extent.

SIGN UP TO OUR PAGE A world without insects is in fact impossible and we, i.e. humans, appeared on it relatively recently. Our species is a tiny fraction. Insects have lived for almost 900 million years and we for only a quarter of a million. We are a small, insignificant episode in relation to them. If humans disappeared the insects would not notice at all.

In a word, insects are a powerhouse and a useful one as well?

Yes, they are a powerhouse pervading the entire terrestrial biocenosis. They are everywhere; many plants, moreover, have been shaped by their dictates. We, as participants in this biological history, are not free from various arrangements with insects. Although in our culture they are often perceived in a negative way.

In school, children are taught silly things like that toad is useful because it eats insects. There are many animals that eat insects. That's the way the food chain is, that's the relationship between the two, inseparable.

Japanese culture, for example, does not treat insects with contempt or disdain. Somehow it has happened that our European culture, especially the central one, has at some point created a kind of insect atavism, and I would like to emphasise once again that without insects there really is no world. It is harder to imagine it without them, much easier without humans.

You said that nature was adapting to insects in a certain way. Can we give some specific examples?

Flowers or most songbirds are dependent on insects. Especially the flying ones, such as swallowtails, hedgehogs, but also many others. In a way, the world of insects is reflected in them, and the same is true of flowering plants or those that bear fruit. For them, insects are pillars without which they cannot exist somewhat like in the construction industry. A cathedral without pillars would quickly collapse. It is very similar in nature.

When you talk about flowers and insects, the first that comes to mind is the bee. For centuries referred to as the queen, today it is seen as an insect that needs to be saved, which is essential both for nature and also for man.

According to the theory of evolution, man descended from the ape, and apes were fruit-eaters. The sweeter the fruit was, the more nutritious it was. This craving for sugar, moreover, has remained with us to this day. At a time when refining from beet or sugar cane was not yet possible, the true and only sweetness was honey. And this was produced by one type of bee, the honeybee. The selection of honey thus became an important issue in human endeavour. Sooner or later, this activity was joined by the aforementioned enormous desire for this sweetness.

Over many thousands of years, man has tamed the bee. It is true that apiary managements were dated as far back as ancient Egypt, but these European bees were forest animals all the way up to the 19th century. In central Europe, they lived in hollows and it was from these that the honey was robbed. Man behaved a bit like a bear. At some point, he came up with the idea of keeping bees in the forests. Holes were hollowed out and bees were attracted to them by some means. They were usually placed quite high up, so that animals such as the aforementioned bears and badgers could not get into them.

This was the bee-keeping economy, then slowly over time it was brought down to earth and the hollows were drilled into tree logs, until finally, although also relatively recently, only 200 years ago, structures reminiscent of today's beehives appeared. From then on, the great supply of honey began, although sugar production also took place in parallel.

Nevertheless, the bee began to have a unique status in the culture. It did not disappear, but died, and it was and is very industrious and causal, because it is thanks to it that man has, for example, rape. In a word, it worked, and still works today, on people's imagination.

And the aforementioned mosquitoes and ticks? Are they needed?

Because I am a naturalist, it is difficult for me to adopt the optics that something is needed or not, especially for humans. This is an obvious reality for me. I am not a person of faith, so I do not believe that God created the world to serve man. Similarly, I don't believe that there is good and evil in nature, these are purely human knickknacks that we have created for ourselves along with culture and our self-awareness. If something that exists and lives in this nature disturbs us terribly, we try to deal with it somehow.

Ticks have always been around, we do not live in a paradise, but in a world of various parasites, which can be pathogenic, and arthropods, of which ticks are our greatest enemies, but are just as bad for rodents, wolves, lynxes and hares. An evolutionary artery of sorts has emerged, which has been remarkably skilfully used and enjoyed by all sorts of germs, which have taken a particular liking to ticks. We too have been in it for some time.

As for mosquitoes, they are quite sterile nowadays, but the malaria epidemic was still present in the 1960s in Radom district. Before that, it was the bane of areas around rivers and marshes. Although we can sleep well for the time being, it is important to remember that the world being in the tropics or subtropics is saturated with mosquito-borne germs.
As our climate warms, diseases such as malaria could return to us quite by accident. From research published by, for example, Lancet Planetary Health, a pessimistic scenario is that climate change and the rate of increase in emissions we have today could put 9 out of 10 people worldwide at risk of contracting malaria or dengue fever by 2080.

Is the rash of ticks also linked to the fact that the climate is warming?

Yes. Their micro-evolutionary process has caused them to switch from deer to all sorts of game - from hares to hounds. The fact that there are so many of them has also caused the lack of forests. Nowadays ticks are not really present in forests, and if they are, it is along roads, although they are mostly found in meadows and wastelands. It is the clearing of forests, the disappearance of traditional crops and the appearance of a large amount of uncultivated land that has given ticks better conditions and increased their numbers.

Meadow ticks used to be really scarce; today, all you have to do is walk along a meadow where animals walk and you can 'collect' a dozen or even several dozen in early spring. I was vaccinated against tick-borne encephalitis as a student in the 1970s, but in those days hardly anyone had heard or talked about Lyme disease.

During the Second World War, lice were insects used for scientific research and, in a way, to save lives.,

Yes. Those who worked at the Rudolf Weigl Spotted Typhus Research Institute in Lvov during the occupation said that it was a lucrative job, which was not easy to get, but thanks to which you could get wages, extra rations of bread and, above all, guarantee your safety.

This institute became a shelter for more than 5,000 people. They all worked as lice feeders. This involved placing these insects in small cages with one wall of fine mesh. Each such box contained about 500 insects. They were strapped to the skin on their legs - men on their calves, women on their thighs - so as to hide the bite marks.

The feeders had been vaccinated beforehand, but often contracted a milder form of typhoid fever, which could be severe but not fatal. When they recovered, they continued to feed the lice. The kennel managers made sure that the process took no longer than 45 minutes, as the insects themselves could not detach from the body and would burst. This procedure, in which they were injected with typhoid germs and fed human blood, helped create a vaccine that protected people from this dangerous disease.

Record-breakers fed around 8,000-10,000 lice a day, and showing a girl that you were a lice feeder raised the ratings.

A colleague of the lice, the bedbug was in turn used in the old days to dye fabrics.

This was a marginal issue, as Polish cochineal was more commonly used to dye fabric. This is where the name of this insect came from, because the colour it gave was indeed very crass. Bugs were more often used as medicine, mainly by the Chinese. Tinctures were made from them to cure everything bit by bit. Did they help? It is difficult to tell.

And coming back to Polish cochineal , it was exported very heavily from Poland in the 14th-15th centuries. Whole barges packed with these insects sailed down the Vistula to Gdańsk, and from there they were distributed all over the world. It was not until an insect was discovered living on the prickly pear in South America and Mexico that our native Polish cochineal was displaced by a competitor from distant countries. It fell into oblivion and became a rarely used insect for dyeing.

Cochineal, on the other hand, is still used today, if only in the food industry, to colour food. In raspberry yoghurt, for example, the red colouring often comes from this insect.

So eating the insects around which there has been so much noise lately is hardly a novelty?

All red jellies, if we don't want to have chemicals in them, we just colour them with cochineal, which is now mainly supplied by the Canary Islands. In the past, when lacquer was used, lac cochineal was also imported from India. And as for eating insects. After all, we also eat animals that eat insects.

Bezpośrednie jedzenie owadów zanikło w europejskiej kulturze prawdopodobnie w wczesnym średniowieczu. Jedyne dania z owadów, jakie przetrwały w niektórych regionach Francji i w Niemczech to wiosenny rosół z chrabąszczy, który do dziś jest swego rodzaju delikatesem. Owady to świetnej jakości białko, dużo łatwiejsze w pozyskaniu w niektórych regionach świata, niż białko świń, czy krów. Pamiętajmy też, że szarańczą żywił się chociażby święty Jan. To był delikates, pokarm wyższych sfer.

Norwegian biologist Anne Sverdrup-Thygeson, author of the book 'Tera Insecta', says that limulus are the insects thanks to which we have vaccines for, among other things, COVID-19, and thanks to ants, antibiotics are created.

Limulus has blue blood, similar to haemoglobin, except that it is not iron-based, but copper-based. If we look at the fruit fly in this context, it has in turn helped with genetic research. As early as the 1930s, genes were mapped in a laboratory in the USA thanks to it. If it were not for the fruit fly, we would still be in our infancy in this field today.

I had a student from India, very ambitious, who was interested in the insect heart because it's a great model for studying the heart muscle in humans. It works on a similar principle.

Artificial embryos in an artificial uterus

They can be used for toxicity tests and drug analysis

see more
And as for ants, it has indeed been discovered that one species of ant uses antibiotics as a pesticide. This study involved mushroom ants, which lived in South and Central America and the southern USA. These ants cultivate mushrooms with which they feed the larvae and the queen. On this occasion, they have learnt to cope with pests such as bacteria or other undesirable fungal species. To do this, they use antibiotics to inhibit the growth of unwanted organisms. These are produced by bacteria that live on the ants' carapaces as part of a symbiosis. It turns out that these antibiotics can be successfully used to treat at least some fungal infections.

Then let's talk for a moment more about perhaps not so much the cultural, social but the propaganda use of the insect.

You are probably referring to the potato beetle, which the communist authorities were convinced was dropped on us by the Americans. I saw this news with my own eyes in the press at the time (laughs). The beetle was a large herbivorous beetle that lived peacefully in the Rocky Mountains and did not get in anyone's way. At some point from these mountains, it fell into a potato field and it turned out to be an Eldorado of sorts for it. Although he had successfully eaten thorny plants before, the potato somehow particularly appealed to him.

Thus, along with shipments of potatoes, it was moved to Europe and became established here too. In the 1920s, the beetle was combated by pouring turpentine over the fields. There were no beetles during the occupation, but after the war, because it was a flying, prolific and voracious insect, its population increased and was used for propaganda purposes. The authorities thought the people were stupid and would buy the story of America dropping us a crop-destroying vermin. Thus the beetle, which is very nice and of which there are about 500 species, was disgusted with the Poles for many years.

What can we humans do to ensure that insects are well and that we don't disturb them too much? For example, not mowing lawns?

This mowing thing is something of a craze, men in particular love this activity. However, if these lawns were not mowed at all, we would have even more ticks. It's not all that clear-cut. It's important to leave some tribute to nature in the garden, if we have one, in the form of flowering plants or wild nettles.

And what good can we do for insects? The best thing is to let them eat us after we die. Even if we get burnt, some will find us and eat us too. I once read about an Oxford resident who wished his body to be eaten by beautiful beetles after death, but I guess his last request was not granted.

– Interviewed by Marta Kawczyńska
- Translated by Tomasz Krzyżanowski

TVP WEEKLY. Editorial team and jornalists

Marek Kozłowski, Ph.D., is an emeritus professor at the Warsaw University of Life Sciences (SGGW) with wide-ranging interests in the natural sciences, author of numerous publications on plant-insect relationships, chemoreceptor physiology, insect behavioural ecology, and invasive pests. He was vice-president of the Polish Ethological Society for many years. He published books on insects, min. "Insects of Poland" and "Beetles of Poland". He has made several television nature films (also in collaboration with the BBC and David Attenborough).
Main photo: Flea development, from egg to adult. Antonie van Leeuwenhoek, around 1680. Photo Wikimedia/ CC-BY-4.0, CC BY 4.0
See more
Interviews wydanie 22.12.2023 – 29.12.2023
Japanese celebrate Christmas Eve like Valentine’s Day
They know and like one Polish Christmas carol: “Lulajże Jezuniu” (Sleep Little Jesus).
Interviews wydanie 22.12.2023 – 29.12.2023
Red concrete
Gomułka was happy when someone wrote on the wall: "PPR - dicks." Because until now it was written "PPR - Paid People of Russia".
Interviews wydanie 8.12.2023 – 15.12.2023
Half the world similarly names mothers, fathers and numerals
Did there exist one proto-language for all of us, like one primaeval father Adam?
Interviews wydanie 24.11.2023 – 1.12.2023
We need to slow down at school
Films or AI are a gateway to the garden of knowledge. But there are not enough students who want to learn at all.
Interviews wydanie 17.11.2023 – 24.11.2023
The real capital of the Third Reich
Adolf Hitler spent 836 days in the Wolf's Lair. Two thousand five hundred people faithfully served him in its 200 reinforced concreto buildings.