Arxiu de la categoria: ENGLISH

War against plastic

The fact plastics cause problems in ecosystems, biodiversity and human health is well known. In fact, being aware of this, the European Union win ban in 2021, some single-use plastic objects and has established some measures for others. Let’s see what we can do to fight this war against plastic!

WAR AGAINST PLASTIC

REASONS TO FIGHT PLASTIC USE

According to a study published in 2015, it is estimated that there are 5.25 trillion plastic particles in the world’s oceans, equivalent to a weight of 268,940 tons. If we focus only at the Mediterranean Sea, there are about 2,000 tons of plastic particles. It is also known that 80% of marine plastic comes from land. Another study points, in addition, that by 2050 there will be more plastics than fish in the seas and oceans of the planet not to stop the current trend.

pantai pede, labuan bajo, indonesia, plasticos, basura marina, plastico marino, guerra plastico, residuo zero
In a beach of Labuan Bajo, Indonesia, it was strange not to find waste or plastic in every single step (Picture: Marc Arenas).

As we already talked in this other article, marine litter, of which 75-85% are plastics, causes serious problems in biodiversity, its habitats and the economy. In fact, it is known that every year one million birds and 100,000 marine mammals die from plastic.

The problem of plastic also affects our health. According to a study published in the recent weeks, microplastics have been detected in the excrements of all people who participated in the study. The presence of plastics in the body can be dangerous for the immune system and cause diseases due to their toxins.

HOW CAN WE LIFE WITHOUT PLASTIC?

We must recognise that, nowadays, living without plastic is quite complicated. The reason is that it is infinitely easier to find a product in a plastic container than in a glass one, or even without it, that is, in bulk. Does this mean that we cannot beat the plastic battle? Obviously, not, but we’ll have to make a little effort.

FORBIDDEN PLASTICS FOR THE EUROPEAN UNION

We have already said that the European Union will ban some plastic items in 2021. These objects are plates, glasses and cutlery, drinking straws and cotton buds. Considering that in two years we will not find them in the stores, go ahead to the prohibition and implement these alternatives.

Using plastic cutlery, plates and cups at a party with many people is comfortable, and if they are colourful it is even fun, but it is totally unsustainable. Alternatives:

  • In the market you can find these objects made with alternative materials. In particular, they are usually made of corn, so that when you finish your party or picnic you can throw them into the organic fraction, since they are compostable. You can also find them in paper, although they are less resistant and less sustainable.
  • Another alternative is to use your metal cutlery, your ceramic dishes and your crystal glasses. Simpler, smarter and more sustainable!

Plastic straws are a problem for the environment, since many of them end up in the sea.

In the United States alone, 500 million straws are consumed every day. Maybe you are going to think that this is why it is a very populated country. Well, in Spain every day 13 million are consumed and it is the European country in which they consume the most. If you are one of those who need (need!) to drink a soft drink or cocktail with a straw, we have an alternative for you.

  • At home, we can use reusable bamboo or metal straws. They are equally effective and you will be collaborating to avoid images like the ones in the video being repeated.
  • Do you really need to drink with a straw? If you only find plastic straws in a bar, pub, club or restaurant, reject it (but before they bring you the drink!). Surely you will survive!

The ear buds are another of the prohibited objects from 2021 since it is one of the most found among marine debris.

bastoncillos oidos, basura marina, caballito de mar, plastico, plastico marino, residuo zero, justin hofman
Cotton buds will be forbidden from 2021 (Picture: Justin Hofman)

Apart from the fact that the health authorities only advise its use for the external ear, if you cannot avoid its use, you should opt for alternatives to the plastic ones:

  • Use cotton buds made with bamboo or other woods which, in addition, are sold in recycled cardboard boxes.
  • If you want to be even more sustainable and reduce your garbage production, there is another better alternative: buy a metal stick as we recommend in this article and put a piece of clean cloth on a tip to absorb the water from the shower.

SUSTAINABLE ALTERNATIVES TO OTHER PLASTIC ITEMS

Plastic bottles also harm the environment. Did you know that it takes up to 1,000 years to degrade one bottle? In addition, to make each plastic bottle it is needed 100 mL of oil. For sure, many of you will be thinking about water, but the truth is that this also applies to soaps, detergents, softeners… Seeing how these bottles are accumulating, we give you some tips:

  • Buy larger bottles. It is needed less plastic for a bottle of 1L than for 4 of 250 mL.
  • For the specific case of water, use canteens to avoid the use of plastic. You can drink tap water if in your town has the right quality, but if it is not the case you can install an osmosis or buy water jugs (remember what we said in the previous point).
  • Observe what products you consume at home in plastic bottles and look for a store in your area that sells them in bulk.

Plastic bags, although their use is being reduced, are another problem. In Spain, according to Cicloplast, each year 97,000 tons of plastic bags are consumed, of which only 10% are recycled.

  • How easy and comfortable it is to go shopping with cloth bags, a trolley or a shopping basket!

Finally, we will now focus on polystyrene trays and plastic film. These two elements are increasingly common in supermarkets and homes, since supermarkets sell their fresh product packed in them. Some advises:

  • If your supermarket only sells meat, fish… in these containers, opt for a local store, which will sell it in bulk and you can also buy just the amount you need.
  • Go shopping in bulk stores and take your tupperware (best glass) from home to avoid plasticized paper (which goes to landfills) or the aforementioned objects.

We are aware that we have forgot many things to comment due to plastic is very present in our lives, but the best thing is to become aware of the plastics we generate every day to find an alternative to each of them.

What do you do to avoid the use of plastic? Leave us your advice in the comments for others to join this war against plastic.

(Cover picture: El Observador Crítico)

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Insects are becoming smaller: miniaturization

According to different studies, multicellular organisms tend to become smaller and smaller through time. This phenomenon is called miniaturization and is considered one of the most significative evolutionary trends among insects. Miniaturization is a driving force for diversity and evolutionary novelties, even though it must deal with some limitations.

Learn more about this phenomenon and met some of the most extreme cases of miniaturization among insects through this post.

Why are animals becoming smaller?

For some years now, multiple studies suggest there is a widely extended trend to miniaturization among multicellular animals (i. e. organisms composed by more than one cell).

Miniaturization is a remarkable natural phenomenon headed to the evolution of extremely small bodies. This process has been observed in different non-related groups of animals:

  • Shrews (Soricomorpha: Soricidae), mammals.
  • Hummingbirds (Apodiformes: Trochilidae), birds.
  • Diverse groups of insects and arachnids.

To know more about giant insects, you can read Size matters (for insects)!

Diversification and speciation processes have given place to lots of new species through time, all of them constantly competing for limited space and food sources. This scenario turns even more drastic in tropical regions, where diversification rates are extremely high.

Learn about the ecological niche concept by reading “The living space of organisms“.

Facing the increasing demands of space and resources, evolution has given place to numerous curious phenomena such as miniaturization to solve these problems: by becoming smaller, organisms (either free-living or parasites) gain access to new ecological niches, get new food sources and avoid predation.

Despite many animals tend to miniaturization, this phenomenon is more frequently observed among arthropods, being one of their most remarkable evolutionary trends. Moreover, arthropods hold the record of the smallest multicellular organisms known to date, some of which are even smaller than an amoeba!

Guinness World Record of the smallest insects

The smallest arthropods are crustaceans belonging to the subclass Tantulocarida, which are ectoparasites of other groups of crustaceans, such as copepods or amphipodes. The species Tantulacus dieteri is still considered the smallest species of arthropods worldwide, which barely measures 85 micrometers (0,085 millimeters), thus being smaller than many unicellular life beings.

However, insects do not lag far behind.

Mymaridae

Mymaridae (or fairyflies) are a family of wasps inside the superfamily Chalcidoidea from temperate and tropical regions. Adults, ranging from 0.5 to 1 millimeter, develop as parasites of other insects’ eggs (e. g. bugs, Heteroptera). For this reason, fairyflies are very valuable as biological control agents of some harmful pests. Also, they are amongst the smallest insects worldwide.

Currently, the one holding the record as the smallest known adult insect is the apterous (wingless) male of the species Dicopomorpha echmepterygis from Costa Rica, with a registered minimum size of 0.139 millimeters. They neither have eyes nor mouthparts, and their legs endings are deeply modified to get attached to the females (somewhat bigger and winged) time enough to fertilize them. They are even smaller than a paramecium, a unicellular organism!

You can read “Basic microbiology (I): invisible world” to know more about unicellular organisms.

Male of D. echmepterygis. Link.

Fairyflies also include the smallest winged insects worldwide: the species Kikiki huna from Hawaii, with and approximate size of 0.15 millimeters.

Trichogrammatidae

Like fairyflies, trichogrammatids are tiny wasps of the superfamily Chalcidoidea that parasite eggs of other insects, especially lepidopterans (butterflies and moths). Adults of almost all the species measure less than 1 millimeter and are distributed worldwide. Adult males of some species are wingless and mate with their own sisters within the host egg, dying shortly after without even leaving it.

The genus Megaphragma contains two of the smallest insects worldwide after fairyflies: Megaphragma caribea (0.17 millimeters) and Megaphragma mymaripenne (0.2 millimeters), from Hawaii.

A) M. mymaripenne; B) Paramecium caudatum. Link.

Trichogrammatids also have one of the smallest known nervous systems, and that of the species M. mymaripenne is one of the most reduced and specials worldwide, as it is composed by only 7400 neurons without nucleus. During the pupae stage, this insect develops neurons with functional nuclei which are able to synthetize enough proteins for the entire adulthood. Once adulthood is reached, neurons lose their nuclei and become smaller, thus saving space.

Ptiliidae

Ptiliidae is a cosmopolitan family of tiny beetles known for including the smallest non-parasitic insects worldwide: the genera Nanosella and Scydosella.

Ptiliidae eggs are very large in comparison with the adult female size, so they can develop a single egg at a time. Other species undergo parthenogenesis.

Learn some more about parthenogensis by reading “Immaculate Conception…in reptiles and insects“.

Currently, the smallest Ptiliidae species known and so the smallest non-parasitic (free living) insect worldwide is Scydosella musawasensis (0.3 millimeters), from Nicaragua and Colombia.

Scydosella musawasensis. Link (original picture: Polilov, A (2015) How small is the smallest? New record and remeasuring of Scydosella musawasensis Hall, 1999 (Coleoptera, Ptiliidae), the smallest known free-living insect).

Consequences of miniaturization

Miniaturization gives rise to many anatomical and physiological changes, generally aimed at the simplification of structures. According to Gorodkov (1984), the limit size of miniaturization is 1 millimeter; under this critical value, the body would suffer from deep simplifications that would hinder multicellular life.

While this simplification process takes places within some groups of invertebrates, insects have demonstrated that they can overcome this limit without too many signs of simplification (conserving a large number of cells and having a greater anatomical complexity than other organisms with a similar size) and also giving rise to evolutionary novelties (e. g. neurons without nucleus as M. mymaripenne).

However, getting so small usually entails some consequences:

  • Simplification or loss of certain physiological functions: loss of wings (and, consequently, flight capacity), legs (or extreme modifications), mouthparts, sensory organs.
  • Considerable changes in the effects associated with certain physical forces or environmental parameters: capillary forces, air viscosity or diffusion rate, all of them associated with the extreme reduction of circulatory and tracheal (or respiratory) systems. That is, being smaller alters the internal movements of gases and liquids.

So, does miniaturization have a limit?

The answer is yes, although insects seem to resist to it.

There are several hypotheses about the organ that limits miniaturization. Both the nervous and the reproductive systems, as well as the sensory organs, are very intolerant to miniaturization: they must be large enough to be functional, since their functions would be endangered by a limited size; and so, the multicellular life.

.             .            .

Multicellular life reduction seems to have no limits. Will we find an even smaller insect? Time will tell.

Main picture: link.

Pharmacogenetics: a drug for each person

Sometimes, some people say that the medications prescribed by doctors are not good. Can this be true? Not all drugs work for the same population. Keep reading and discover the secrets of pharmacogenetics.

INTRODUCTION

The same that happens with nutrients, happens with drugs. Another objective of personalized medicine is to make us see that not all medicines are for everyone. However, it does not come again because around 1900, the Canadian physician William Osler recognized that there was an intrinsic and specific variability of everyone, so that each one reacts differently to a drug. This is how, years later, we would define pharmacogenetics.

It is important to point out that it is not the same as pharmacogenomics, which studies the molecular and genetic bases of diseases to develop new treatment routes.

First, we need to start at the beginning: what is a drug? Well, a drug is any physicochemical substance that interacts with the body and modifies it, to try to cure, prevent or diagnose a disease. It is important to know that drugs regulate functions that our cells do, but they are not capable of creating new functions.

Apart from knowing if a drug is good or not for a person, you also have to take into account the amount that should be administered. And we still do not know the origin of all diseases, that is, we do not know most of the real molecular and genetic causes of diseases.

The classification of diseases is based mainly on symptoms and signs and not on molecular causes. Sometimes, the same group of pathologies is grouped, but among them there is a very different molecular basis. This means that the therapeutic efficacy is limited and low. Faced with drugs, we can manifest a response, a partial response, that produces no effect or that the effect is toxic (Figure 1).

efectivitat i toxicitat
Figure 1. Drug toxicity. Different colours show possible responses (green: drug not toxic and beneficial; blue: drug not toxic and not beneficial; red: drug toxic but not beneficial; yellow: drug toxic but beneficial) (Source: Mireia Ramos, All You Need is Biology)

DRUGS IN OUR BODY

Drugs usually make the same journey through our body. When we take a drug, usually through the digestive tract, it is absorbed by our body and goes to the bloodstream. The blood distributes it to the target tissues where it must take effect. In this case we talk about active drug (Figure 2). But this is not always the case, but sometimes it needs to be activated. That’s when we talk about a prodrug, which needs to stop in the liver before it reaches the bloodstream.

Most of the time, the drug we ingest is active and does not need to visit the liver.

active and prodrug
Figure 2. Difference between prodrug and active drug (Source: Agent of Chemistry – Roger Tam)

Once the drug has already gone to the target tissue and has interacted with target cells, drug waste is produced. These wastes continue to circulate in the blood to the liver, which metabolizes them to be expelled through one of the two routes of expulsion: (i) bile and excretion together with the excrement or (ii) purification of the blood by the kidneys and the urine.

THE IMPORTANCE OF PHARMACOGENETICS

A clear example of how according to the polymorphisms of the population there will be different response variability we find in the transporter genes. P glycoprotein is a protein located in the cell membrane, which acts as a pump for the expulsion of xenobiotics to the outside of the cell, that is, all chemical compounds that are not part of the composition of living organisms.

Humans present a polymorphism that has been very studied. Depending on the polymorphism that everyone possesses, the transporter protein will have normal, intermediate or low activity.

In a normal situation, the transporter protein produces a high excretion of the drug. In this case, the person is a carrier of the CC allele (two cytokines). But if you only have one cytosine, combined with one thymine (both are pyrimidine bases), the expression of the gene is not as good, and the expulsion activity is lower, giving an intermediate situation. In contrast, if a person has two thymines (TT), the expression of the P glycoprotein in the cell membrane will be low. This will suppose a smaller activity of the responsible gene and, consequently, greater absorption in blood since the drug is not excreted. This polymorphism, the TT polymorphism, is dangerous for the patient, since it passes a lot of drug to the blood, being toxic for the patient. Therefore, if the patient is TT the dose will have to be lower.

This example shows us that knowing the genome of each individual and how their genetic code acts based on it, we can know if the administration of a drug to an individual will be appropriate or not. And based on this, we can prescribe another medication that is better suited to this person’s genetics.

 APPLICATIONS OF THE PHARMACOGENETICS

The applications of these disciplines of precision medicine are many. Among them are optimizing the dose, choosing the right drug, giving a prognosis of the patient, diagnosing them, applying gene therapy, monitoring the progress of a person, developing new drugs and predicting possible adverse responses.

The advances that have taken place in genomics, the design of drugs, therapies and diagnostics for different pathologies, have advanced markedly in recent years, and have given way to the birth of a medicine more adapted to the characteristics of each patient. We are, therefore, on the threshold of a new way of understanding diseases and medicine.

And this occurs at a time when you want to leave behind the world of patients who, in the face of illness or discomfort, are treated and diagnosed in the same way. By routine, they are prescribed the same medications and doses. For this reason, the need has arisen for a scientific alternative that, based on the genetic code, offers to treat the patient individually.

REFERENCES

  • Goldstein, DB et al. (2003) Pharmacogenetics goes genomic. Nature Review Genetics 4:937-947
  • Roden, DM et al. (2002) The genetic basis of variability in drug responses. Nature Reviews Drug Discovery 1:37-44
  • Wang, L (2010) Pharmacogenomics: a system approach. Syst Biol Med 2:3-22
  • Ramos, M. et al. (2017) El código genético, el secreto de la vida. RBA Libros
  • Main picture: Duke Center for Applied Genomics & Precision Medicine

MireiaRamos-angles2

 

The problem of wild animals as pets

Although the first animals we think of as life partners are dogs or cats, the truth is that unfortunately many people decide to have a wild or exotic animal at home. Vietnamese pot-bellied pigs, sugar gliders, fennec foxes, meerkats, raccoons, monkeys… Is it possible to have a wild animal in good condition at home? What are the issues we can find? What wild mammals do people have as pets? We invite you to continue reading to find out.

WHAT IS THE DIFFERENCE BETWEEN A DOMESTIC ANIMAL AND A WILD ONE?

A domestic animal is an animal that has lived with humans for thousands of years. During the history of our species we have artificially selected these animals to obtain benefits, such as food, companionship or protection, like dogs, which have even co-evolved with us. Most domestic animals could not survive in the wild, as they would not know how to find food or would be easy prey for predators. Those who survive when abandoned, like some dogs or cats, cause serious problems to wildlife or even people.

 lobo perro dog wolf perro lobo
Some domestic animals, such as certain dog breeds (right), resemble their wild counterparts (wolf, left), which gives rise to the false idea that wild animals can be domesticated. Photo: unknown

And a wild animal? Many people confuse wild animal with ferocious or dangerous animal. A wild animal is an animal that has not been domesticated, that is, its species has not been in contact with people (at least not for thousands of years as the domestic ones). The fact that some wild animals are not dangerous (or not at all) for us, that they appear in series and movies, some celebrities own them and the desire to have a “special” animal at home, continues favoring the purchase-sale of these animals as pets.

monkey mono capuchino marcel ross friends
The character of Ross in the world-famous series ‘Friends’ had a capuchin monkey, which has to be donated when it reaches sexual maturity for aggressive behavior. Source

WHAT PROBLEMS DOES IMPLY TO HAVE A WILD ANIMAL AT HOME?

PROBLEMS FOR PEOPLE

The main reason why wild or exotic animals cause problems for humans is the lack of knowledge of the species: some have very specific diets that are practically impossible to reproduce in captivity. Others may live longer than the owner, be very noisy, occupy a lot of space, have nocturnal habits, transmit diseases or be poisonous. This results in maintenance difficulties and changes in  the behavior of the animal, until it becomes dangerous for its owner. The consequence is usually the abandonment of the animal, which will cause death, cause problems in nature or very high maintenance costs if they end up in a wildlife rescue center (according to Fundació Mona, keeping a chimpanzee costs 7,000 euros a year. Their life expectancy is 60 years: 420,000 euros in total for a single animal).

Raccoons undergo behavioral changes and may attack their owners. Source

Many species released in the wild end up being invasive, endangering the native ecosystems. If you want to know the difference between introduced and invasive species, read this post. To know the threats they pose to ecosystems, visit this post.

Do not forget that the purchase, sale and possession of many wild animals is totally illegal.

PROBLEMS FOR ANIMALS

Animals must live in an environment where their needs, both physical and mental, can be met. Although we put all our good intentions, give love and spend money keeping a wild animal, we  will never be able to reproduce their natural conditions. Lack of space, contact with other animals of their species, time searching for food, temperature conditions, humidity, light… the animal can not develop its normal behavior even if it is in the most optimal conditions of captivity.

The consequences that will suffer an animal that has not met their needs implies health problems (diseases, growth deficit…) and behavior (stereotypic-compulsive movements, self-injury, anxiety, aggression…).

A fennec fox, a carnivorous animal of the desert, in an evident state of illness. According to social networks, because he was being fed a vegan diet. According to its owner, Sonia Sae, because it is allergic to pollen despite following a vegan diet. Be that as it may, it is clear that the pollen amounts in Sahara have nothing to do with those of Europe. Source

Finally, the most serious consequence when we acquire a wild animal is that we are favoring the trafficking of animals, the death of thousands of them during transport to our house and even their extinction. Animal trafficking is the second cause of biodiversity loss on our planet, behind the destruction of habitats.

Slow loris are nocturnal and poisonous animals that are marketed as pets and, like mostof them, are transported under terrible conditions. Learn more about the calvary of slow lories visiting blognasua. Photo: Naturama

EXAMPLES OF WILD MAMMALS AS PETS

PRIMATES

Marmosets, slow loris, lar gibbons, chimpanzees, Barbary macaques… The list of primates that people have in captivity is almost infinite. One of the main mistakes people make when they want a primate as a pet is to believe that they have our same needs, especially in superior primates such as chimpanzees. Its expressions are also confused with ours: what the photo shows is not a smile of happiness and what the video shows is not tickling, but an attitude of defense (slow loris have poison in their elbows).

This chimpanzee is not smiling, he is scared. Photo: Photos.com

Many primates live in family groups and the offspring need to be with the mother the first years of life, so that just the simple fact of acquiring a little primate entails the death of all the adults of their family group and psychological problems for the animal. To know the extensive and serious problem of keeping primates in captivity, we strongly recommend reading this post.

SUGAR GLIDERS

Sugar gliders (Petaurus breviceps) resemble a squirrel, but in fact they are marsupials. They have a very specific diet (insects and their depositions, eucalyptus sap, nectar …), they live in the canopy of trees in groups from 6 to 10 individuals and move between the trees jumping up to 50 meters with a membrane that let them hover. They are nocturnal so they yell and call at night. It is evident that it is impossible to reproduce these conditions in captivity, so the majority of sugar gliders die due to nutritional deficiencies.

Sugar glider caged. Photo: FAADA

VIETNAMESE POT-BELLIED PIGS

Although they are a variety of a domestic animal, Vietnamese pot-bellied pigs (Sus scrofa domestica) are small when tey are young, but adults can weigh more than 100 kilos, so it is impossible to keep them in a flat. There have been so many abandonments and they have reproduced so much, that there are populations established in nature. They can reproduce with wild boars and it is unknown if the hybrids are fertile. There are no wildlife recovery centers or shelters for these pigs, so they continue to affect the native ecosystems.

Since actor George Clooney introduced a Vietnamese pot-bellied pig as a pet, the trend to own one quickly spread. Source

RACCOONS AND COATIS

Other mammals that, because of their pleasant appearance, some people try to have as pets. Raccoons (Procyon sp) develop aggressive behaviors when they do not having their needs covered, they are destructive to household objects and have a tendency to bite everything, including people. Currently in Spain and other countries it is illegal to acquire them and it is classified as an invasive species.

In addition to aggressiveness, one of the most common behaviors of raccoons is “theft”. Source

Coatis (Nasua sp) are related to raccoons and, like them, when they grow up they become aggressive if kept in captivity in a home. In Spain, their possession is also illegal.

coatí nasua
The coati, another friendly-looking mammal that can be dangerous. Source

MERKAATS

Merkaats (Suricata suricatta) are very social animals that live in colonies of up to 30 individuals underground in the South African savanna. They usually make holes in the ground to protect themselves and are very territorial. Therefore, having a meerkat at home or in a garden is totally unfeasible. In addition, the climatic conditions (high temperatures and low humidity) in which they are adapted are not the same as those of a private home.

As sugar gliders, their food is impossible to reproduce at home: snake meat, spiders, scorpions, insects, birds and small mammals… Like raccoons, they do not hesitate to bite and are very active animals.

Meerkat with a leash where you can see his fangs. Photo: FAADA

FENNEC FOX

This species of desert fox (Vulpes zerda) has also become trendy as a pet. Although its tenure is still legal, it has been proposed several times as an invasive species.

The main reason why you can not have a fennec at home are the desert climatic conditions to which it is adapted. Living in an apartment causes kidney problems and thermoregulation problems. Also, it is a nocturnal animal. Changes in their circadian rhythm cause them hormonal problems.

Fennec  fox in the desert. Photo: Cat Downie / Shutterstock

Like the previous two species, behavioral problems can turn up and become violent against the furniture or its owners.

ELEPHANTS, TIGERS …

Although it may seem incredible, there are people who have an elephant in the home garden and other people have felines, like tigers. At this point we do not think it is necessary to explain the reasons why these animals have not their needs met and the potential danger they pose to their owners and neighbors in case of escape.

Dumba, the elephant that lives in a home garden in Spain. Photo: FAADA

IN CONCLUSION

As we have seen, a wild animal in captivity will never have its needs covered to guarantee its welfare. Here we have presented the best known wild mammals that are kept as pets, but unfortunately the list does not stop expanding.

In order not to favor animal trafficking and cause unnecessary suffering during the life of the animal, avoid buying wild animals, inform yourself and inform the people around you, denounce irresponsible tenures and in case you already have one wild animal as a pet and you can no longer keep it, contact a recovery wildlife center and never abandon it into nature.

MIREIA QUEROL ALL YOU NEED IS BIOLOGY

 

Known the Asian hornet or ‘assassin hornet’ in 5 steps

In recent years, reports of invasive species entering the Iberian Peninsula have grown at an alarming rate. One of the most recent cases is that of the Asian hornet, also known as the yellow-legged hornet and dramatically called ‘assassin hornet’, which is well-stablished in northern regions of the Iberian Peninsula and which has recently been confirmed to nest in the very center of Barcelona.

What do we know about this species? Why is it known as the ‘assassin hornet’?

1. Where does it come from and how did it get here?

The Asian hornet (Vespa velutina) is a social wasp native to the Southeast Asia. It was for the first time recorded in Europe in 2004, at southeast France, where it is currently well-spread. According to most of sources, it is believed that some founding queens accidentally arrived France inside boxes of pottery from China.

Some associations of beekeepers from the Basque Country confirmed the presence of the Asian hornet in the Iberian Peninsula in 2010. From that moment on, the Asian hornet started spreading toward other regions: it was recorded in Galicia in 2011, in Northern Catalonia and in some areas of Aragon in 2012, in some areas of La Rioja and Cantabria in 2014 and in Mallorca, in 2015.

Dynamic map by José Luis Ordóñez – CREAF

Meanwhile, this species spread toward Italy, Portugal, Germany, Belgium, Sweden and, occasionally, the United Kingdom. It presence in Japan and Korea, where it is an invasive species too, was confirmed some years before.

It was recorded for the first time in Catalonia in its northern comarques (‘counties’), specifically in Alt Empordà, and in 2015 almost 100 nests of this species had already been recorded. Nowadays, the Asian hornet is well-spread in Girona and Barcelona provinces.

On July 13th of this year (2018), the Generalitat de Catalunya (Government of Catalonia) confirmed the first record of an Asian hornet nest located in the very center of Barcelona city, close to one of the main buildings of the University of Barcelona; a few days before, it had also been detected in Vallès Oriental and Baix Llobregat.

2. How can we identify it?

The Asian hornet size varies between 2 and 3.5 cm, approximately. Queens and workers have a similar morphology except for their size, being workers smaller than queens.

This species can be recognized by the following morphological traits:

  • Thorax entirely black.
  • Abdomen mainly black except for its 4th segment, which is yellow.
  • Anterior half of legs, black; posterior half, yellow.
  • Upper part of head, black; face reddish yellow.
Dorsal and ventral view of Vespa velutina. Picture by Didier Descouens, Muséum de Toulouse, CC 3.0.

If you think you have found an Asian hornet and meant to notify authorities, first of all make sure it is the correct species. This is of special importance as some native species like the European hornet (Vespa crabro) are usually confused with its invasive relative, thus leading to misidentifications and removings of native nests.

Vespa crabro. Picture by Ernie, CC 3.0.

3. Why is it also called ‘assassin hornet’?

The Asian hornet is neither more dangerous, venomous nor aggressive than other European wasps. So, why is it dramatically called ‘assassin hornet’?

Larvae of this species feed on honeybees caught by adult hornets. Honeybees usually represent more than 80% of their diet, while the remaining percentage is compound of other arthropods. Adult hornets fly over hives and hunt the most exposed honeybees, even at flight. A single hornet can hunt between 25 and 50 honeybees per day. Hornets usually quarter them and get only the thorax, which is the most nutritious part.

In Asia, some honeybees have developed surprising defensive mechanisms to fight against their predators, like forming swarms around hornets to cause them a heat shock.

Take a look to this video to known some more about this strategy (caso of Japanese honeybees and hornets):

On the contrary, European honeybees have different defensive strategies that seem to be less effective against invasive hornets than they are against the European ones, which are also less ravenous their Asiatic relatives and their nests, smaller. In addition, the absence of natural predators that help to control their populations makes their spreading even more easier.

Several associations of both beekeepers and scientists from Europe have been denouncing this situation for years, since this invasive species is causing severe damages to both the economy (honey and crop production) and the environment (loss of wildlife -insects and plants- biodiversity) due to the decrease in wild and domestic honeybees.

4. How do their nests look like and what I have to do if I find one?

Asian hornets usually make their nests far from the ground, on the top of trees (unlike the European hornets, which never construct their nest on trees at great highs); rarely, nests can be found on buildings near non-perturbated areas or in the ground. Nests are spherical-shaped, have a continuous growth, a single opening in their superior third from which internal cells cannot be appreciated (in European hornet’s nests, the opening is in its inferior part and internal cells can be observed through it) and can reach up to 1 m height and 80 cm diameter. Nests are made by chewed and mixed wood fibers, leaves and saliva.

Nest of Asian hornet. Picture by Fredciel, CC 3.0.

If you find an Asian hornet nest, be careful and don’t hurry: don’t get to close to it (it is recommended to stay at least 5m far from the nest), observe and study the nest and observe if there are adults overflying it. If you find a dead specimen, you can try to identify it (REMEMBER: always staying far from the nest!). Anyway, the most recommendable thing is to be careful and call the authorities (in Spain, to the emergency phone number: 112).

5. There are preventive and management measures?

Currently, preventive and management measures proposed are the following:

  • Protocols for a more efficient detection of nests.
  • Early detection of the hornet by installing traps.
  • Constitution of an efficient communication net to provide information of the presence of this species between regions.
  • Removal of nests.
  • Capture of queens.
  • Improving the habitat quality to minimize the settlement of the Asian hornet and enhacing the settlement of native bees.
  • Study the possible introduction of natural enemies.

In the following link, you can download the PDF (in Spanish) made by the Spanish Government (2014) where these and more strategies are widely explained.

Citizen participation is a key point when fighting against the spreading of an invasive species; the same happens with the Asian hornet. Some associations of beekeepers, like the Galician Beekeeping Association (Asociación Gallega de Apicultura, AGA) and its campaign Stop Vespa Velutina, give educational conferences about this species and place traps to control their populations. Also, some students of the University of the Balear Islands have developed a mobile app to inform about the expansion of the Asian hornet.

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Although knowledge of this species has been improved, there is still much work to be done. We will see how its populations evolve in the coming years.

Main picture by Danel Solabarrieta on Flickr, CC 2.0.

 

How can you help biodiversity of the cities?

Towns and cities have increasingly become hostile to biodiversity. Fortunately, a few years ago there is a growing interest to make cities more friendly to the native fauna and flora. Discover what you can do for urban biodiversity!

HOW CAN YOU HELP BIODIVERSITY OF THE CITIES?

According to SEO BirdLife, 10% of the bird species that live in Spain are housed in urban environments. In fact, some of them, like the sparrow, depend on human presence. In spite of that, these species are in decline.

They also assure that urban birds in Spain have suffered a decrease of over 18% in the last 20 years. For the case of the barn swallow (Hirundo rustica), the loss amounts to 44% of its individuals.

promocionar biodiversidad urbana, biodiversidad urbana, golondrina común, hirundo rustica, biodiversidad ciudades, fauna ciudades
The barn swallow (Hirundo rustica) has lost 44% of its urban population (Picture: Ferran Pestaña, Creative Commons).

BENEFITS OF URBAN BIODIVERSITY FOR PEOPLE

Biodiversity in cities is positive for human beings, beyond the ornamental function, since it offers a set of very important services that improve our quality of life. In fact, the WHO recommends that in cities there are between 10 and 15 m2 of green areas per inhabitant and that the inhabitants have a green area less than 300 m from their house.

In addition to the benefits that nature has for human health and well-being, green areas cushion the temperature (important to reduce the effect of heat islands), purify the air and fix CO2. It is also responsible for the pollination of crops and, in general, to increase the resilience of the environment.

health benefits of nature, promocionar biodiversidad urbana, biodiversidad urbana, golondrina común, hirundo rustica, biodiversidad ciudades, fauna ciudades
Nature has a positive effect in the human health and wellness.

WHAT CAN WE DO FOR URBAN BIODIVERSITY?

Broadly speaking, to help the biodiversity of cities, we must:

  • Provide enough urban green areas in the cities and that they are distributed throughout the area.
  • Have urban green spaces connected between them and with the natural environment.
  • Generate diversity of habitats.
  • Do not plant invasive species.
  • Do not use chemical treatments.
  • If the green areas are illuminated, make sure it is not annoying for the fauna.

We must bear in mind that, if we have cats at home, we must consider if it is worth doing some of the actions we propose, since our feline friends are great predators and, rather than helping the fauna, we could be harming it.

PLANT TREES, BUSHES AND FLOWERS THAT PROMOTE BIODIVERSITY

Obviously, if we plant native trees or shrubs we will be favouring the biodiversity of our city. If we do not meet this first point and plant exotic invasives, we will be questioning the future of our area. In addition to this fact, we must add other considerations.

The trees or bushes that produce fleshy fruits, such as the olive tree (Olea europea), the strawberry tree (Arbutus unedo) or the lentisk (Pistacia lentiscus), will be able to sustain a part of the diet of some animals. The olive tree also generates holes, which may serve as a nest for some birds. If we look for species that bear fruit in winter, when conditions are more difficult due to the reduction of food, it will also be of great help.

promocionar biodiversidad urbana, biodiversidad urbana, biodiversidad ciudades, fauna ciudades, madroño, arbutus unedo
Trees with fleshy fruits promote the presence of food for many animals (Picture: Creative Commons).

Softwood trees, such as poplar (Populus), will allow some birds, such as the Iberian green woodpecker (Picus sharpei), to make holes in its trunk, which will cause that when leaving the nest other species can be installed. We can also leave dead trees standing for the Iberian green woodpecker to make its nest.

Combining deciduous and perennial trees will allow a refuge for wildlife throughout the year.

As for the plants, it is highly recommended to plant indigenous aromatic plants, which will attract a large number of pollinating insects. In the Mediterranean area, you can choose rosemary (Rosmarinus officinalis), lavender (Lavandula stoechas), savory (Satureja montana), thyme (Thymus vulgaris), sage (Salvia officinalis), basil (Ocimum basilicum)…

promocionar biodiversidad urbana, biodiversidad urbana, biodiversidad ciudades, fauna ciudades, lavanda, lavandula stoechas, plantas aromáticas
Indigenous aromatic plants will favour the presence of pollinators (Picture: Kurt Stüber, Creative Commons).

INSTALL NEST BOXES

If there were old trees in the cities (and in the natural areas), it would not be necessary to install nest boxes. The reason is that the old trees have holes, in which the chickadees, the tits, the owls, etc. make a nest. But not only can you install nest boxes for birds, you can also do them for bats, which are effective mosquito eaters.

promocionar biodiversidad urbana, biodiversidad urbana, biodiversidad ciudades, fauna ciudades, caja nido, herrerillo comun, Cyanistes caeruleus
Installing nest boxes will promote the presence of some birds, such as the Eurasian blue tit (Cyanistes caeruleus) (Picture: Creative Commons)

On the other hand, there are animals that use buildings to breed, such as the peregrine falcon (Falco peregrinus), the kestrels, the crow (Corvus corax), the common swift (Apus apus), the common gecko (Tarentola mauritanica), etc. .

In general, in the Iberian Peninsula there are about 40 species of birds and a dozen mammals that can use nest boxes to breed and rest.

In this Grup Ecologista Xoriguer and VOLCAM Voluntariado Ambiental‘s guide you will find information about how to build yourself a nest box and other tips.

BUILD A INSECT HOTEL OR OTHER STRUCTURES FOR FAUNA

An insect hotel is a construction with a wooden structure that is full of different materials, such as natural cane, stones, tiles, bricks, pineapples, perforated wood or straw, which serve as a hiding, resting and breeding place for various species of insects.

Although you can buy them, we recommend you do it yourself with a little imagination. Collect these materials and about 6-7 wooden pallets and start to build a new home for solitary bees (solitary bees are not aggressive, unlike colonial ones), ladybugs (they will eat the aphid you have in your garden), lacewing, syrphids…

promocionar biodiversidad urbana, biodiversidad urbana, biodiversidad ciudades, fauna ciudades, hotel insectos, hotel insectos palets
Insect hotel with pallets (Picture: unknown author).

The construction of dry stone spirals with aromatic plants will also favour the presence of fauna, especially reptiles.

In a corner of your garden, you can leave a pile of trunks in the shape of a pyramid. You will see that in a while it will be colonised by mosses, fungi, xylophagous insects, lizards…

VEGETATION MAINTENANCE TASKS

All this is meaningless without sustainable maintenance of green infrastructure. What good is it to plant trees with fleshy fruits if we prune them in full fruition?

Here are some tips:

  • Do not prune in the time when the trees are in fruit, concentrate them during the winter.
  • Avoid pruning all trees and shrubs the same year.
  • Decrease the number of prunings and ask that they be less drastic. So there will be structures that can support large nests.
  • Do not remove all the leaves from the ground, since leaf litter allows the development of the invertebrate fauna and incorporates organic matter into the soil.
  • Do not use chemical pesticides or phytosanitary products. If you have a pest, use biological control systems against them.

ASK YOUR LOCAL ADMINISTRATION TO JOIN IN THE PROMOTION OF URBAN BIODIVERSITY

Some of these tips will be easy to implement, others will be less. In addition to applying it in your own home, ask your local administration to apply these principles. Together we will make towns and cities more sustainable in which biodiversity can also live!

In addition to the points already mentioned, local administrations can do some other tasks that are within their competence:

  • Naturalise artificial lakes. What if, instead of having ponds with crystal clear water, we took advantage of these points to favour the presence of amphibians, reptiles and aquatic vegetation?
  • Change lawns for natural meadows. What if instead of having large expanses of green grass, typical of northern Europe (where water is plentiful), we had spaces with different species of native flowers that attracted large numbers of pollinators and birds? Some birds, such as the zitting cisticola or streaked fantail warbler (Cisticola juncidis) or the European stonechat (Saxicola rubicola), make nests in the middle of meadows.
  • Reduce the mowing of the lawns (better done at the end of winter) and make differential mowing. What if instead of completely mowing the lawn we did it irregularly to allow the growth of spontaneous vegetation that attracted the invertebrates?
  • Plant in the tree clogs. What if instead of having tree clogs full of dog droppings we had them full of flowers that attract the insects that control the plagues of the tree that is planted in it?

Have we encouraged you to apply any of the measures we present? Tell us what you are doing to help urban biodiversity in the comments of this article.

(Cover picture: Kevin Cole, Creative Commons)

Insects feel through their antennae

Insects perceive their surroundings through different organs, among which antennae are some of the most important. Antennae appear in a lot of incredibly diverse shapes and sizes, and every group of insects develops one or more models. We encourage you to know more about their origin, functions and diversity through this post.

The origin of antennae

Antennae are paired sensorial appendages located in the anterior parts of insects’ body. Except for chelicerates (spiders, scorpions…) and proturans (non-insect hexapods), all arthropods, either crustaceans, hexapods (diplurans, springtails -Collembola- and insects), myriapods (centipedes and millipedes) and the extinct trilobites, have antennae when being adults.

In crustaceans, antennae appear in the two first head segments: a first pair known as primary antennae or antennules, and a longer second pair known as secondary antennae or just antennae. Usually, secondary antennae are biramous (that is, they have two main branches), even though some crustaceans have undergone ulterior modifications so antennae appear as uniramous appendages (with a single branch) or even get reduced.

Types of antennae in crustaceans. Picture obtained from Wikipedia (link).

However, the rest of arthropods only have a single pair of uniramous antennae. Hexapods (like insects), which seem to be closely related to crustaceans according to the pancrustacean model, seem to have just preserved the secondary pair of antennae typical of crustaceans.

According to some authors, antennae appear to be true appendages; that is, they would start to develop during the embryological development from a head segment the same way legs do. However, this segment would have evolved into a reduced and inconspicuous piece, now being unappreciable. Moreover, antennae can also regenerate like legs.

How do insects feel through antennae?

So, what does this title exactly mean?

Antennae are microscopically covered with tiny hairs known as sensilla, which are not related with hairs found in vertebrates since they are made of chitin (as the rest of insect’s cuticle) instead of keratin.

Picture above: antennae under electronic microscope. Picture below: detail of the sensilla. Both images taken from cronodon.com.

Despite being almost identical at the first sight, there are different types of sensilla: chemoreceptorial sensilla have an inner channel through which suspended molecules enter (e.g. pheromones), while mechanoreceptorial sensilla are retractable and move at the slightest pressure or when the insect changes its position with respect to the ground (in this case, these are called proprioceptor sensilla).

So, insects taste, smell, touch and communicate in part through antennae, thus allowing them to gather information about food sources, potential mates (pheromones), enemies, dangerous substances (e. g. a poisonous plant), nesting places and migratory routes (as in the case of the monarch butterfly). Other organs, such as legs, palpi and even the ovipositor (organ for laying eggs) sometimes have sensorial cells.

Inside and in the base of sensilla there are sensorial neurons connected to the insect’s brain; specifically, a brain region known as deutocerebrum. In chemoreceptorial sensilla, molecules bind with specific receptors that send nervous signals to the antennal lobe through the sensorial neurons. This lobe is somewhat like the olfactory bulb found in vertebrates.

Types of antennae in hexapods

Except for the proturans, which are wingless hexapods, diplurans, springtails (collembola) and insects develop different types of antennae. These are divided in two main groups:

  • Segmented antennae: springtails and diplurans. Each segment has an own set of muscles that moves it independently from the rest of the antenna.
  • Flagellate antennae: insects. Just the first segment located at the base of antennae in contact with the insect’s head (the scapus) has an own set of muscles, so the antennal movement depends entirely on this segment.

Parts of insects’ antennae

The three basic segments of insects’ antennae are the following:

Antenna of an inquiline wasp belonging to the genus Synergus (Hymenoptera). Picture by Irene Lobato.

1) Scape: basal segment that articulates with the insect’s head and the only one that has an own set of muscles. The scape is mounted in a socket called torulus.

2) Pedicel: the second antennal segment or the one that comes just after the scape. This segment has a relevant role since it contains the Johnston’s organ, which is a collection of sensory cells. This organ is absent in non-insect hexapods (springtails, diplurans).

3) Flagellum: the rest of antennal segments that form the antennae, which are individually known as flagellomeres. These flagellomeres are connected by thin membranes that allow them to move as a whole despite not having muscles.

Thousands of antennae!

From this basic pattern (scape + pedicel + flagellum), each group has developed numerous antennal models based on their lifestyle:

  • Aristate

These are very reduced antennae with a pouch-like shape and a small bristle that emerges from its third modified segment.

Example: a very extended model among flies (Diptera).

Left: picture by M. A. Broussard, CC 4.0; right: picture of a fly of the family Sarcophagidae by JJ Harrison, CC 1.0.
  • Capitate

Capitate antennae have a club or knob at their ends.

Example: usually found in butterflies (Lepidoptera) and in some beetles (Coleoptera).

Left: picture by M. A. Broussard, CC 4.0; middle: picture of a beetle of the species Platysoma moluccanum by Udo Schmidt, CC 2.0; left: a butterfly, public domain.
  • Clavate

Unlike the capitate ones, clavate antennae get progressively thicker in their ends.

Example: moths (Lepidoptera), carrion beetles (Silphidae, Coleoptera).

Left: picture by M. A. Broussard, CC 4.0; right: beetle of the species Thanatophilus sinuatus (Silphidae) by Wim Rubers, CC 3.0.
  • Filiform

This is the simplest model of antennae: long, thin and made of equally sized and shaped segments.

Example: cockroaches (Blattodea), crickets and grasshoppers (Orthoptera), longhorn beetles (Cerambycidae, Coleoptera), bugs (Heteroptera).

Left: picture by M. A. Broussard, CC 4.0; right: cockroach of the species Periplaneta americana by Gary Alpert, CC 3.0.
  • Flabellate

These are quite similar to pectinate and lamellate antennae (see below), but with thinner and flattener segments that make them to look like a folding paper fan; also, these thin projections occupy all the antenna, and not only the terminal segments as in lamellate antennae. This model is found in males of some insects, thus having a large surface for detecting pheromones.

Example: beetles (Coleoptera), wasps (Hymenoptera) and moths (Lepidoptera).

Beetle male of the genus Rhipicera. Picture by Jean and Fred, CC 2.0.
  • Geniculate

These are bent, almost like a knee joint. The first antennal segment (scape) is usually located before the joint. The rest of segments together are known as funicle.

Example: some bees and wasps, especially in chalcid wasps (Hymenoptera), weevils (Curculionidae, Coleoptera).

Left: picture by M. A. Broussard, CC 4.0; right: picture of a parasitoid wasps of the species Trissolcus mitsukurii, public domain.
  • Lamellate

The terminal segments enlarge to one side in form of flat and nested projections, thus looking like a folding fan.

Example: beetles of the family Scarabaeidae (Coleoptera).

Left: picture by M. A. Broussard, CC 4.0; right: picture of a beetle of the family Scarabeidae, public domain.
  • Moniliform

Unlike filiform antennae, the segments of moniliform antennae are more or less spherical and equally sized, thus giving these antennae a string of bead appearance.

Example: termites (Isoptera), some beetles (Coleoptera).

Left: picture by M. A. Broussard, CC 4.0; right: picture of a termite by Sanjay Acharya, CC 4.0.
  • Pectinate

Segments have a lateral projection, so they look like combs.

Example: sawflies (Symphyta, Hymenoptera), parasitoid wasps (Hymenoptera), some beetles (Coleoptera).

Left: picture by M. A. Broussard, CC 4.0; right: picture of a beetle of the family Lycidae by John Flannery, CC 2.0.
  • Plumose

Plumose antennae look like feathers as their segments have numerous thin branches. Having a bigger antennal surface allows them to detect more suspended molecules, like pheromones.

Example: mosquito (Diptera) and moth (Lepidoptera) males.

Left: picture by M. A. Broussard, CC 4.0; right: moth male of the genus Polyphemus by Megan McCarty, CC 3.0.
  • Serrate

Each segment is angled or notched on one side, thus making these antennae to look like saws.

Example: some beetles (Coleoptera).

Left: picture by M. A. Broussard, CC 4.0; right: picture of a beetle of the family Chrysomelidae by John Flannery, CC 2.0.
  • Setaceous

These antennae are bristle-shaped, being thinner and longer in their ends. They are quite similar to filiform antennae, but thinner.

Example: mayflies (Ephemeroptera), dragonflies and damselflies (Odonata).

Left: picture by M. A. Broussard, CC 4.0; right: picture of a dragonfly, public domain.
  • Stylate

Similar to filiform antennae, but the terminal segments are pointed and slender, looking like a style. The style can either have bristles or not.

Example: brachycerous flies (Diptera).

Left: picture by M. A. Broussard, CC 4.0; right: picture of a brachycerous fly of the family Asilidae by Opoterser, CC 3.0.

You can read more about the different antennal models here and here, or take a look to the antennal gallery by John Flannery.

Main picture by Jean and Fred, CC 2.0.

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If you know more antennal models or curious facts about insects’ antennae, feel free to share it with us by leaving a comment below!