INSETTI XXL Exhibition. English version

GIANT INSECTS

1. GIANT INSECTS

More than three-quarters of all living species on the Planet are insects.

There are at least 1000 kg of insects for everyone. The main reasons for such incredible performances are:

– the small size which allows the exploitation of ephemeral and low-value resources,

– the ability to fly, which allows them to spread widely and quickly take advantage of resources that suddenly available resources,

– a formidable instinct that intelligently leads them to the best choice,

– a huge variety of forms and adaptations, which offers them ample opportunities to exploit the most disparate environments, from  poles to deserts, from forests to cities, crops, rivers and lakes.

This exhibition with enlarged 3D sculptures and touchable panels will offer you a unique way to enter their incredible and wonderful world.

2. BIODIVERSITY

We have today over one million insect species listed even if it is estimated that such number is probably 10 times bigger.

During their evolutionary history, insects have experimented an infinite number of incredible shapes and colors.

Without them, Mankind would disappear.

The most impressive species of the past lived during the Carboniferous period, about 300 million years ago.

At that time, insects were the only masters of the air, and thanks to a richer atmospheric oxygen rate they could reach the size of a today’s falcon.

Meganeura, with her wingspan of 70 cm, preyed on other invertebrates and even small amphibians.

Today insects have greatly reduced their size due to the reduction in oxygen content that occurred after the Carboniferous Period and the appearance of better flying predators such as dinosaurs and then birds and bats.

In recent times we have witnessed the disappearance of many insect species, mainly due to pesticides.

This very serious fact puts the balance of the natural environment and crops at risk as bees are the main crop pollinators.

LABELS:

Insect evolutionary tree.

Prehistoric dragonfly Meganeura, female, life size.

3. ORIGIN

Insects originated in fresh-water areas from small shrimp-like crustaceans which, together with plants and other living beings, conquered the emerged lands about 450 million years ago.

Initially wingless, they first developed active flight less than 400 million years ago.

This new ability determined their incredible success and allowed the rapid diversification and evolution of the entire group.

THE INVENTION OF FLIGHT

Some today’s jumping silverfish, even if wings-less are capable of performing efficient gliding flight with ample maneuvering possibilities.

They have rigid wings that are simple lateral expansions of the exoskeleton.

To maneuver they use frontal (Antennae) and abdominal (Cerci) appendages such as balance wheels and rudders.

Starting from situations like that, it is thought that active flight may have developed somehow. How exactly, is still unknown.

The first insects with active flight (named Paleodictyoptera) had 3 pairs of wings, one for each leg.

Then for better flight efficiency, the first pair of wings aborted, resulting in today’s situation typical of winged insects with 2 pairs of wings.

After the development of the first forests, insects that lived under the bark thickened their front wings to protect the more delicate hind wings, a typical situation of today’s cockroaches.

Subsequently there was a reduction in the number of veins and nodes which led to membranous wings similar to those of more modern insects such as flies, wasps, butterflies…

LABELS:

Hypothetical ancestor of winged insects

Paleodictyoptera

Insect wings

ANATOMY

1. HEAD

Composed of 6 segments fused together whose ancient appendages had transformed into antennas, mandibles, maxillae and labium.

The Insect head houses the main senses: sight (thanks to large compound eyes), smell (on the antennae) and taste (on the mouth appendages and under the legs).

The hearing is located on the front legs as it happens in beetles and grasshoppers, or on the thorax itself, as occurs in flies.

Sensory organs

The internal parts of insects are protected by a very resistant and elastic armor called “Exoskeleton”.

External stimuli can reach the insect through holes opened throughout the surface of the body where special sensors exist.

Different sensors produce chemical, physical, mechanical, optical, etc. sensations specific to each species.

DIET:

Insects eat almost anything,

They are equipped with very specialized mouthparts for stinging, sucking, licking, absorbing, cutting, collecting…

Some insects do not have a mouth as adults, such as Mayflies.

Some others, as fireflies adult males, although equipped with mouths, do not feed at all.

LABELS:

Cockroach Head

– The antennas are extremely sensitive to specific odors.

Setaceus – Serrate – Pectinate – Plumose – Aristate – Lamellate.

– Compound eyes generally allow very broad and reactive vision. Lenses – Cornea – Crystalline cone – Retinula cell – Rhabdom – Axons.

– Flies and butterflies have taste sensors under their legs.

Sucking – Butterfly

Licking – Bee

Killing – Cicindela

Stinging – Cicada

Absorbing – Moscow

Chewing – Grasshopper

2. THORAX

Insect thorax is made up of 3 joined segments. Each one brings a pair of legs and wings (with the exception of the first segment).

The thorax is equipped with powerful muscles that move wings and legs.

Insects don’t have lungs.

By the way, they have a dense network of tubules called “tracheae” which branches out throughout the body to directly carry atmospheric oxygen to each cell.

3 holes on each side of the thorax allow air entry.

LEGS:

Insect legs are articulated appendages of the thorax generally responsible for terrestrial locomotion but also suitable for carrying out other functions such as swimming, catching preying, digging, jumping, fighting…

LABELS:

Dragonfly thorax.

Insect legs:

– Excavation (Mole Cricket)

– Jumping (Grasshopper)

– Running (Formica)

– Harvesting (Bee)

– Catching (Mantis) – Swimming (Notonetta)

3. ABDOMEN

It is composed of approximately 11 segments with terminal appendages transformed into organs for egg-laying, stingers or other.

The abdominal segments slide over each other acting like a small bellows that expands rhythmically for breathing.

The abdomen contains the animal’s intestine and is responsible for reproduction as the exclusive seat of both the internal and external genital apparatus.

EGG:

Insect eggs have variable shapes depending on the species.

They can be perfectly round, oval, more or less elongated, bean-shaped, barrel-shaped, lenticular, flat, attached to surfaces, suspended by filaments or encapsulated…

Stick insect’s eggs are shaped as small seeds in order to deceive the ants and get carried inside ant’s warm and protected anthills.

Some fly species are viviparous and give birth to perfectly alive young larvae.

LABELS:

Grasshopper abdomen.

Insect eggs

LIFE CYCLE

1. SIMPLE METAMORPHOSIS

The transformation of the newborn insect into an adult, which occur in several different ways depending on the type of development, is called Metamorphosis.

The simple metamorphosis, typical of ancestral wingless insects, involves simple progressive dimensional growth without any variation.

LABELS:

Insect eggs contain the developing embryos surrounded by a protective covering.

The nymph is a juvenile form similar to the adult and always has no wing buds.

Moulting is the process that allows the insect to grow in size.

As the body is enclosed in a rigid armor, in order to grow each insect is forced to abandon its old skeleton several times and to reform a new, larger one.

Silver fish on paper.

(On the strip with the vertical arrow: egg, nymph, nymph, nymph, nymph, nymph, adult)

2. INCOMPLETE METAMORPHOSIS

The incomplete metamorphosis, typical of primitive winged insects, is caracterized by juvenile forms still very similar to adults.

This type of development often forces adults to have the same diet as juvenile forms, which involves considerable competition amoung generations.

LABELS:

Juvenile forms of this type of development are called “nymphs”.

Nymphs have a gradual wing development.

Dragonflies, grasshoppers, mantises, termites, cockroaches, stick insects… are insects with incomplete metamorphosis.

Bugs on tomato.

3. COMPLETE METAMORPHOSIS

The complete metamorphosis, typical of the most advanced winged insects, evolved about 200 million years ago.

It involves a type of growth whose juvenile forms are extremely different from adults and generally have a different diet.

Such diversification allows adults not to compete with young larvas for food.

Thanks to this, in some species the juvenile forms grow in volume very quickly until they exceed the size of the adult

DIDASCALIE:

The juvenile forms are called “larvae” (or caterpillars as amoung butterflies).

The pupa is that intermediate form that involves the total destruction of the larval tissues from which the new adult tissues are reformed.

Ants, flies, mosquitoes, butterflies, moths, bees, wasps, beetles, ladybugs… they are insects with complete metamorphosis.

Colorado beetle on potato leaves.

MAN AND INSECTS

1. DISEASES

Just because insects are winged and spread everywhere, they have always been used as vectors by many pathogens and parasites.

Many blood-sucking insects are used by many parasites to easily enter other animal bodies.

Because of the mosquitoes, some very dangerous organisms such as the malaria Plasmodium have been able to infect and kill up to now over 10 billion human beings.

Other blood-sucking dipterans, such as the Tze-tze flies, which carry the Trypanosoma brucei parasite are the onset of serious diseases as the sleeping sickness.

Another pathogen such as the Plague, responsible for billions of people death around the world uses wingless insects as vectors (fleas), thus it is forced to take advantage of the mices on which fleas live in order to disperse over vast territorithere is ikbecause they find abundant food there, are responsible for the spread of many diseases such as. Fooes.

Cockroaches, so active in the vicinity of our homes, are responsible of many different kind of diseases: tuberculosis, typhoid fever, dysentery, hepatitis, gastroenteritis, tapeworm, allergies…

LABELS:

World distribution of the Malaria disease

Anopheles mosquito, female, 20x.

The-tze fly, female 20x.

Distribution of sleeping sickness.

Painting depicting the Plague in the Middle Ages.

Cockroach on food scraps.

Periplaneta cockroach, male 20x

2. AGRICULTURE

Firstly the ants invented agriculture (and livestock breeding) many millions of years ago, long before Mankind appeared on earth.

Human agricultural practices started only by 10-15 thousand years ago. Because of that the genetics of plants was modified in order to make them more productive and adaptable, many animals were attracted to these new, larger and more nutritious foods, including insects.

As a consequence, new defenses systems were inplemented in order to keep insect populations under control.

That because in absence of an effective defenses, insects would increase incredibly their numbers leading agricultural production to destruction on very large areas.

Some insects such as locusts which alternate phases of solitary life and gregarious life, can form gigantic swarms capable of devouring everything.

Other insects such as beetles move underground, feeding on the roots of plants, from below, escaping the sight of farmers.

Then there are weevils and mealworms that feed on the seeds stored in silos…

… and fruit flies, cabbage and tomato caterpillars, shieldbugs that damage a large number of varieties with their bites, beetles of all types specialized on attacking specific parts such as roots, stems, leaves, flowers, fruits and seeds.

LABELS:

Swarm of Locusts

Grasshopper head

Beetle larvae

Wheat weevil

Ants collecting seeds

3. ENTOMOPHAGY

In many countries around the world, from Central America to Africa, Asia and Oceania, the practice of eating insects is very common, as it probably was in Europe throughout Prehistory.

Insects in fact represent an important source of proteins and fats available in poor economies.

From a nutritional point of view there are some reservations about the quality of this food as the value of such foof depends on the quality of the food that the insects have digested, which is not always very excellent or free from hormones and chemicals.

Among the best known and easiest insects to breed for human food use are the flour moths (or mealworms). They are used to prepare snacks, “ragù”, croquettes, “panzerotti”…

The fat larvae of the Palm Weevil can be eaten in many ways: on a spit, roasted on the grill or breaded and fried in a pan.

Wasp or bee larvae are cooked in soy sauce and sugar and enjoyed as a crunchy snack… they are very sweet..

The list of edible species includes locusts, grasshoppers and crickets, cicadas, water bugs, bamboo worms, fly larvae, dragonflies, ants, mealworms…

Finally, it may happen that insects, instead of being eaten as food by people, become eaters of human bodies.

The interesting thing is that depending on the time that has passed since death the corpse is attacked by different communities of insects:

First come the flies such as the Sarcofaga cartaria (sarcophagus, i.e. devourer of muscles) and then the beetles such as the Necroforo vessillo (necrophore, i.e. bearer of a corpse, death).

LABELS:

Mealworms

Fried insects

Wasp larvae

Fly larvae

INSECTS AND ENVIRONMENT

1. ALIEN SPECIES

Globalization, with the huge movement of goods around the world, has favored the spread of many animals and plants species that would never have had the opportunity to reach other places of the world.

Very aggressive species or simply adaptable to new geographical contexts, in the absence of competitors, can cause very serious damage and upset the delicate balance present.

One of the most recent pest that is leading palm trees to death is the red weevil.

It is a very showy beetle whose yellow larvae gnaw at the tender vital parts of palm trees until they kill them.

Once the infestation appears it is really too late and the infested trees must be cut down to prevent a larger contagion.

The Japanese Popilia beetle was brought mistakenly to the USA and Canada at the beginning of the 20th century.

In the 1970s it spread to the Azores and then in 2014 it arrived in northern Italy. Today it is still rapidly spreading.

It attacks many varieties including: asparagus, basil, green bean, hazelnut, elm, peach, plum, birch, apricot, hawthorn, cherry, lime, vine.

Italy, which due to favorable climatic conditions is one of the European countries most affected by biological invasions, hosts over 1500 alien species.

After the vine phylloxera of the late 19th century and the potato beetle of the post-war period, many species arrived: the corn rootworm, the Asian bug, the vine aphid, the various citrus scale insects, the fig weevil, the leafminer citrus serpentine, the walnut fly, the well-known tiger mosquito… and many others.

LABELS:

Red weevil, female, 20x

Infested palms (red weevil larva on the right)

Japanese Popilia, male, 20x

Cargo ship with hundreds of containers

2. USEFUL SPECIES

Rarely, some exotic predatory or parasitic species can be purposely introduced as hostile species to other exotic species previously arrived in Italy.

However, the most reliable regulators of the parasitic species that infest Italian crops and woods are those species already well represented on site.

Particularly useful in organic farming, which is known for not allowing the use of pesticides, are some insects such as lacewings (whose nocturnal larvae devour aphids and shieldbugs), earwigs (devourers of eggs and larvae of other insects), hoverflies (flies similar to bees, excellent pollinators as adults and greedy for aphids when young) and then butterflies, bees and bumblebees, and many many others.

Bees are very useful, not just  for the honey, but all over  hg25 thousand known species, as they pollinate flowering plants.

Ladybug beetles, mostly the very useful 7-spot ladybug, are extremely fond of aphids both as larvas and as adults.

There are more than 14 thousand known ant species on the Planeth, some are extremely useful for the health of forests as they are voracious predators of parasitic caterpillars.

The very famous red wood ant is often introduced purposely into infested areas where they are scarce.

Freshwater macroinvertebrates are extremely important for river environments as they digest leaves and woody parts fallen into the water acting as a powerful filter that keeps fresh waters clean and oxygenated.

LABELS:

Pollination

7-spot ladybug, female, 20x

Red wood ant, worker, 20x

Ecdyonurus, nymph, 20x

Freshwater macroinvertebrates lay under submerged rocks

3. PROTECTED SPECIES

Some native species, incapable of opposing environmental degradation, are used as quality indicators and subjects to protection: providing for the defense of such species means saving their entire ecosystem.

There are many endangered species as human activities and globalization have heavy impacts.

The alpine Rosalia, the Stag beetle, the Oak longhorn Cerambix, the Calosoma and then butterflies, fireflies, dragonflies, bees… are the most famous.

The Oak longhorn beetle is one of the most beautiful beetles of the Italian oak woods, whose males are equipped with very long antennas.

The Calosoma sycophant is another beautiful beetle from the Italian pine woods, with an iridescent metallic armor that is unfortunately also greatly appreciated by insect collectors.

LABELS:

Oak forest

Oak longhorn beetle, male, 5x

Calosoma sycophant, male, 5x

Fire alters the biodiversity of an area for centuries

SOCIAL INSECTS

1. TERMITES AND WASPS

TERMITES are the oldest social insects on the planet.

They are the descendants of ancient cockroaches from the Triassic Period.

They are forms that live in the darkness inside nests that they build with their own feces cemented with saliva.

They are divided into social castes, as happens with all other social insects but here we have only the queen but a royal couple, the king and the queen and the workers are both male and female.

They feed on wood which they digest completely thanks to symbiotic bacteria that they host in their intestines.

It is a very poor diet that forces individuals to feed even on their own dead so as not to waste the precious nitrogen.

Some groups build huge termite mounds.

WASPS, insects that generally live solitary lives, with the exception of a few social species, are the forms from which both bees and ants subsequently derived.

They are carnivorous insects that hunt prey individually, usually spiders and insects, which they then chew with their powerful mandibles to form a ball of meat with which to feed the larvae.

Starting from solitary winged forms, parasites of other insects, the loss of their wings led to the appearance of terrestrial forms of wasps similar to ants.

Even today these intermediate forms called Velvet Ants exist.

To build their nests, wasps invented some materials that later inspired humans: paper, mortar and ceramics.

In fact, it is thought that the ideas for the manufacture of these materials were born from the observation of the materials with which these insects build their nests, which led to writing, product conservation and urban construction.

LABELS:

Termite head

Termites and termite mounds

Wasp head

Vespa velvet

Potter wasp

Wasp nest

2. SOCIALITY

The cooperation between individuals of the same species in an organised, continuous and specialized way has allowed the creation of new living entities, the “Superorganisms”.

Individual individuals lose identity and all work together, collaborating altruistically as if they were the cells of a single large social body: the colony.

The colonies often find themselves fighting among themselves and with other species for supremacy and control of the territory and its resources.

With their coordinated and ruthless action, the colonies exploit the territories to the maximum, bringing the less social species with which they come into contact.

From the appearance of the first social forms, over 200 million years ago for termites, 150 million years ago for ants and wasps, and about 100 million years ago for bees, it was only from about 60-50 million years ago that there were truly complex societies.

Since then, social insects have had to solve problems that only millions of years later also affected humans:

– public order, waste disposal, wars, environmental impact, air conditioning of environments, materials suitable for large constructions, public health, population management, specialization and division of labor, food production, slavery…

Due to this commonality that we have with social insects, the study of their behavior has always fascinated man from a philosophical, political and pedagogical point of view (some fairy tales have insects as protagonists).

Among the most famous fables that use insects as an example of human vices and virtues are those of Aesop, a Greek writer who lived 2600 years ago.

His are: “The grasshopper and the ant”, “The eagle and the beetle”, “The grasshopper and the fox”, “The flea and the ox”, “The mosquito and the bull”.

LABELS:

Cutere ants (puppets)

The cicada and the ant

Cuterean ant workers

3. ANTS AND BEES

ANTS owe their existence to the formation of a special gland on their thorax, the “metapleural gland”.

This gland, exclusive to ants, produces antibiotics that allow the elimination of bacteria and fungal spores that would otherwise spread in the narrow, humid and warm spaces of the colony, leading to certain death.

This gland is absent in arboreal forms.

Ants today are the most advanced social form and due to their social organization and their number (it is estimated that there are at least one million ants per human being) they have control of entire areas of the planet.

The development of their societies has led to the extinction of most insects that did not have some form of defense against ants.

For other insects you provided only ephemeral food sources, of little interest to the ants.

All the durable and best resources even today are under their control.

Bees are vespoid forms that, following the appearance of flowering plants in the Cretaceous Period, assumed a floral diet.

They have modified their mandibles transforming them into spoons for collecting pollen and spoons and for handling honey.

They have developed thick fur for collecting pollen and in some cases also specialized comb-like legs for carrying large quantities of pollen.

They invented wax, which they use to build their geometric homes and store honey and pollen.

They also have a symbolic language made up of sounds and dances with which they communicate the direction and distance from the nest of the best blooms to their companions.

Many ruling families have always wanted bees in their noble coats of arms, thinking that they were an example of a perfectly ordered and efficient society, divided into royal and worker castes. The discovery that it was a completely female society governed by workers and not by the queen must have been bitter news.

LABELS:

Ant head

Bee head

Wax and honey

Heraldry with bees

Honey bees