Four species of invasive butterflies have arrived in Israel in recent years. They are beautiful and attract attention. And on the other hand, their arrival is an invasion that raises the issue of whether and how such a beautiful invader could be harmful?
The answer is not simple and will not be in the Israeli language "butterflies, so what's the problem?"

biological invasions

Among the direct causes of the increasing loss of biodiversity in the world, biological invasions are considered one of the most prominent and serious factors. Other factors that have been recognized as having decisive influence and consequences are pollution, climate change, habitat destruction, light pollution and ecological fragmentation. On each of these factors and their many components, there is abundant information, studies and articles available.

The explanation for damage from an invasive species begins with the very definition of the concept:

invasive species (Invasive species) is an organism (mammal, insect, reptile, plant, algae) that has exceeded its natural range and develops a population in the new area.

How does the transition, the invasion, of a species from one area (land, continent, sea) to another occur?
Many species were introduced as a result of intentional human activity such as the smuggling of birds, reptiles, plants or as a result of unconscious activity such as the passage of ships between ports, the transportation of goods, containers and even the transfer of algae that stick to the hull of ships and anchor in the various sea ports.

The climate crisis encourages species migration

The climate crisis is apparently a significant factor in the movement of species to new living areas and habitats, including abandonment and extinction due to the loss of habitats, due to construction for example, and the survival struggle of species to find living conditions.

Evidence of the impact of the climate crisis on the butterfly society in Israel was presented in the 2023 report on the state of Israel's nature presented in May 2024 and was based on research results (Dr. Or Komai, the MRG) from the database and information systems of "National butterfly monitoring program" (community science-citizen project) that I founded and manage since 2009.

The study also reveals measured results of the worsening problem of changes in the growth period of butterfly hosts versus a delay of up to a month in the hatching period of pupae larvae. This is a disruption in synchronization that causes the loss of food sources for the larvae leading to extinction and is directly caused by the climate crisis.

Little intruders huge damage

As a general rule, a new species that succeeds in creating a nucleus of a population in a new area must be based on food sources for its existence and this is where the danger of its presence in the new environment lies. Their populations reproduce, spread and often take over and push to the point of extinction of species in their new environment. This is an event that deteriorates without control and its effect on the functioning of the ecosystems reaches a chain reaction with irreversible damages.

There are countless examples of invasive species in the world and in our country, and here are some of them:

• The migration of hundreds of marine species to the Mediterranean Sea began and continues since the Mediterranean Basin was exposed to the Red Sea in 1869 through the Suez Canal (an ecological event known as "Migration to Spanish" named after Ferdinand de Lesseps, the initiator and planner of the canal).
• a bird The Indian Meena which escaped/was released from the safari in Israel is known as an omnivore, as pushing and competing with local species for food and nesting sites and as causing damage to agricultural crops. Its activity displaced the small songbirds to which we have been accustomed since childhood, sparrows, finches, and sparrows, which have almost disappeared from the northern parts of the country. The migration of hundreds of marine species to the Mediterranean Sea began and continues since the Mediterranean Basin was exposed to the Red Sea in 1869 through the Suez Canal (an ecological event known as the "Lespasian Migration " named after Ferdinand de Lesseps, the initiator and planner of the canal).

• The little fire ant, whose sting is painful and stings like a fire burn, arrived from Brazil via backpackers or imported pots, spread throughout the country and builds nests at an incredible rate, it is also a total omnivore that destroys every living thing in the food chain around it. It was also discovered in Carmel to our dismay. 
  Both the fire ant and the weena were defined by the United Nations as one of the hundred most harmful and dangerous invaders in the world.

• Ailanta Balutit - a kind of tree which was brought to Israel from China and planted in the 60's and 70's along streets and boulevards mainly in Jerusalem. Since then, the tree has been distributed throughout the country and in Carmel, signs of takeover are already visible everywhere, especially in the Vedas inside and outside the city. It is a tree with the highest resistance and distribution capacity and the most difficult to eradicate due to its extremely fast growth skills.

• And known of course The palm weevil The red beetle that hitched a ride on tree trunks brought from the Far East and spread from trucks that carried them along European roads and wiped out most of the palm avenues on the continent (research by Dr. Victoria Soroker). The weevil caused Tunisia to be in danger of eliminating date exports in the country and losing the source of livelihood for hundreds of thousands of families.

Invasive species - huge economic damage to the country

It is true that not every invasive species is a danger, but the threat of damage to agriculture, water, health and the functions and services of biodiversity requires close control. In cases of damage detection, the treatment costs amount to a huge economic damage to the state. That is why in many countries there are a series of prohibitions in connection with these issues, some of them are extremely severe in terms of punishment.

The invading butterflies that flutter to us

like the txix flute (Chilades pandava)

The tsiks flute is an invasive species, which originated in Southeast Asia and probably arrived via Egypt and was discovered and multiplied in Eilat during 2015 on the cultivated tsiks palm bushes, and disappeared forever, apparently due to spraying of ornamental gardens.

In 2019, a small and stable population was discovered near Ashkelon which did not exceed the borders of the area. In September 2023, a new population was discovered in the Upper Galilee and within a few months a rapid spread of the species was observed as far south as Beer Sheva and of course Haifa was not spared either.
The butterfly larvae feed on and damage the young leaves of the cycad bushes, but the degree of damage to the palm bushes is not, for the time being, considered serious. 

Cacyreus marshalli (Cacyreus marshalli)

The Phalaenopsis window was discovered and reported for the first time in November 2019 in the Zipori neighborhood of Jerusalem by a young and talented butterfly monitor (Shalem Korman) and until the middle of 2023 the butterfly's population did not go beyond the Jerusalem area. From then on the distribution map grew throughout the country up to Mitzpe Ramon. Of course it was also observed in Carmel.
Pelargonium is a common garden plant from the Geranium family and apparently the origin of the species is the butterfly pupae that were carried on seedlings imported from abroad. The butterfly originated in South Africa from where it was brought and spread in Europe at the end of the 20th century. The pelargonium plant is slightly harmful to the species of the cultivated pelargonium and pelargonium plants.

Invaders who arrived by way of ecological migration

While the arrival of the cycads and pelargoniums in Israel is attributed to human activity, the next two species arrived in Israel by way of ecological migration through the land, and seem to reflect changes in the distribution map of the species under the influence of the climate crisis.

Prominent examples of the process of ecological migration include the increase in average temperature, which causes the movement of populations to colder areas.

A particularly serious example is observed today in the behavior of fish in the Mediterranean Sea:
The warming of the upper layer of the sea surface causes the fish to go deeper into layers with a colder temperature suitable for them. Also, there are many cases of seabirds dying of starvation because they are unable to dive deep enough to catch fish for food.

Invading butterflies on an ecological migration route

as an American bagpiper (Brephidium exile)

The American bagpiper is an invasive species that originates from dry, desert areas in the western USA. It was probably brought to Europe and arrived from there to the countries of the Persian Gulf and through Jordan/Saudi Arabia to the Dead Sea hotel area.

It was observed, for the first time (by Yuval Evron 2021) on the host Sesobium reglati, a cultivated succulent plant, near the Dead Sea Mall. It has maintained a permanent and apparently harmless population there ever since.
A beautiful and agile little butterfly. The distribution of the butterfly in Israel is still limited to the Dead Sea region and the south.

Lemon Swallowtail (Papilio demoleus)

The lemon swallowtail is a relatively new invasive butterfly in Israel, which was first observed in Kibbutz Afik in the Golan (Miri Hecht 2021) and left its mark in the southern Golan area in a limited population. Since June 2024, it began to spread rapidly south and west, and was first observed in Haifa in August of this year.

The hosts of the species are the citrus trees, with an emphasis on the lemon tree, so there is potential for damage to the citrus trees. However, his enemies from among the parasitic wasps may maintain a state of balance, so it is still too early to determine. It is important to monitor its spread.

It is a large and beautiful butterfly, and unlike the other swallowtail species in the family, it does not have the characteristic tails.

It should be mentioned that the tails of the butterflies, together with a small and colorful eye at the bottom of the wing next to them, create a kind of imitation of a "fake head" designed to mislead ground predators.

Are visiting butterflies invaders?

Regarding the definition of an invader, as long as the process of acclimatization and establishment of a local population has not begun, a butterfly of a new species observed in Israel is not considered an invader. Almost every year we witness the appearance of butterfly visits that have not been seen before in Israel, and sometimes species that were seen in the distant past and disappeared for decades even return.

From the deserts of Arabia and Africa, we met the Hirsan nymph, the leg nymph and the blue nymph, which acclimatized for several years in the south, but disappeared again.

In the north, on the peaks of Hermon, many species arrive from the north; Some of them survive and some become extinct due to vigorous and uncontrolled activity of construction and grazing, which causes fatal damage to the rare habitat found in the area.

The species gallery, and what are the butterfly species observed today

You are invited to get to know more closely List of butterflies of Israel On a site that is dynamically updated directly from the database and information systems of a community citizen science project to which hundreds of butterfly trustees report and record observations every day:National butterfly monitoring program" in Israel.

Here you can see who the butterflies arewere observed today" Every day of the year and also to view a photo gallery of all species from the best butterfly and nature photographers in our country who rush enthusiastically to commemorate every butterfly discovery and event.