Ants of Lebanon

Ants are among the planet’s most abundant insects. One insect out of a thousand is an ant. They play a major role in the ecology of soils. By feeding on organic waste, insects or other dead animals, they play a role of decomposer, keep the environment clean, bring biomass underground and constitute an important meal for passerines.

The high level of complexity of ant colonies does not stop at the limit of their species, since some exploit or parasite other species of ants, or take care of herds of aphids and raise fungi.

On a phylogenitic level Formicidae are a family of hymenoptera, flying insects endowed with two pairs of wings. Among ants, only queens and males still have wings, workers lost it during the evolution. The focus on their petiole, or pedicel (the west of hymenoptera) is the best way to identify the species of the specimens observed.

Ants are polymorphic: not only males (drones) and queens differ in size and shape from the workers, but many species have also two kinds of females, minor (workers) and major (soldiers).

Ant species mainly differ in the size of their colony (from a few hundreds to millions of individuals), their diet (some prey, some gather seeds, some grow fungi or keep a herd of aphids, …).

We are deeply endowed to Georges Tohmé who dedicated his PhD to the topic for our knowledge on the ants of Lebanon. Then, with his wife Henriette, he pursued the study of the ants of Lebanon, and together they identified 110 species in Lebanon (Tohmé&Tohmé, 2014). These species belong to 5 sub-families: the Ponerinae, the Dorylinae, the Myrmicinae, the Dolichoderinae, and the Formicinae.

Ponerinae

The ponerinae are most easily identified from other subfamilies by possessing a single-node petiole with a constriction before the second gastral segment. They also possess a sting. They live in small colonies of hundreds of ants and feed on woodlice. In Lebanon, there are two species of ponerinae, the Ponera punctatissima, and the Ponera libani.

The ants of genus Ponera are known for their unique nesting behavior, as they create their nests in small cavities or “portholes” in trees, rocks, or other natural structures.

Dorylinae

The dorylinae are predatory ants. Also called army ants, they are known for their aggressive behavior and their ability to form large colonies that can contain up to several million individuals.

Only Dorylus fulvus could be found in Lebanon, in the region of Beirut. The genus Dorylus encompasses the driver ants, which are army ants feeding on all types of arthropods. Colonies are enormous and can contain over 20 million individuals. They are nomadic, and do not build permanent nests. Instead, they move their entire colony from place to place in search of food and suitable nesting sites. This behavior is facilitated by the fact that driver ants have no fixed breeding season and can reproduce at any time of year. Workers exhibit caste polymorphism with the soldiers having particularly large heads that power their scissor-like mandibles. They are capable of stinging, but very rarely do so, relying instead on their powerful shearing jaws to prey. When they come across prey, they swarm over it in large numbers, overwhelming it with their sheer numbers and powerful jaws.

They are an important part of many ecosystems. They help to control the populations of other insects and small animals, and they provide food for larger predators such as birds and mammals.

Myrmicinae

The myrmicinae is the hugest subfamily of ants. They are 11 different genii in Lebanon. Main species form little colonies of some hundreds or thousands individuals. They are most easily identified from other subfamilies by possessing a double-node petiole.

Aphaenogaster

Among them three species of Aphaenogaster, also called funnel-ants. These ants are known for their unique nesting behavior, where they construct nests with a funnel-shaped entrance easily located on the ground. Underground, they create a series of chambers and tunnels.

The Funnel Ants feed on both plant and animal matter. They play an important role in their ecosystems, helping to control populations of other insects and contributing to nutrient cycling in the soil.

Crematogaster

Crematogaster are also known as Saint Valentine ant, for their heart-shaped abdomen. Members of this genus are also known as cocktail ants because of their habit of raising their abdomens when alarmed. But their principle nickname is acrobat ants. Indeed, these ants are known for their unique ability to contort their bodies and move in acrobatic ways, hence their name. This allows them to move along narrow branches, twigs, and other surfaces that would be difficult for other ants to navigate.

They are also able to use this ability to escape from predators, such as birds and other insects. Most species are arboreal. They are known to feed on insects, nectar, and honeydew, as well as fruits and seeds.These ants are also known to tend to aphids, protecting them from predators in exchange for the sweet honeydew that the aphids produce. Acrobat ants acquire food largely through predation on other insects, such as wasps. They use venom to stun their prey.

6 species of acrobat ants can be observed in Lebanon.

Leptothorax

They live in colonies that can range from a few dozen to several hundred individuals. This limited number is counterbalanced by “temporary social parasitism.” It allows Leptothorax ants to benefit from the resources of other ant colonies without having to invest in their own colony infrastructure.

4 species can be observed in Lebanon.

Messor

Colonies can achieve huge sizes and are notable for their intricately designed granaries in which seeds are stored in dry conditions, preventing germination.

16 species can be observed in Lebanon.

Tohme & Tohme studied with attention and grew colonies of Messor ebeninus.

Monomorium

Monomorium pharaonis, also known as the Trailing Pharaoh ant, is a small, almost transparent ant species that is commonly found in urban areas, then considered a pest.

Pheidole

Main species of the genus Pheidole are bimorphic: colonies contain two castes of workers, the “minor” workers, and the “major” workers, or soldiers. The latter generally have much larger heads and mandibles in comparison to their usually fairly modest body size.

Pheidole megacephala is a mite-eating ant. It is known for its unique feeding habits, as it primarily feeds on mites and other small arthropods. The colonies are typically divided into two groups: workers and reproductive individuals. The workers are responsible for foraging for food, caring for the young, and defending the colony, while the reproductive individuals are responsible for producing offspring. They use their large mandibles to capture and kill their prey, and then carry it back to the colony to be consumed.

Oxyopomyrmex

These ants are known for their unique physical characteristics, including their elongated mandibles and slender bodies.

Solenepsis

They are also called fire ants for their red color and painful bite.

One of the most distinctive features of fire ants is their ability to sting. They have a stinger located at the end of their abdomen, which they use to inject venom into their prey or enemies. Fire ant stings can be painful and can cause an allergic reaction in some people.

The species present in Lebanon is Solenopsis fugax. It is a thief ant and usually has its nest near another species, stealing food by entering the foreign colony through minute tunnels dug from their own nest.

Tetramorium

Ants of the genus tetramorium are also called pavement ants, they build their nests in cracks and crevices in pavement, sidewalks, and buildings. They play an important role in urban ecosystems, being an important food source for many animals. 13 species can be observed in Lebanon.

Dolychoderinae

This subfamily is distinguished by having a single petiole (no post-petiole) and a slit-like orifice, from which chemical compounds are released. Dolichoderine ants do not possess a sting, instead relying on the chemical defensive compounds produced from the anal gland.

Bothriomyrmex

Bothriomyrmex ants live in colonies that can range in size from a few dozen to several hundred individuals. They are known to tend to aphids and other insects that produce honeydew, which they collect and consume.

Tohme & Tohme studied with attention and grew colonies of Bothriomyrmex syrius.

Liometopum

Velvety Tree Ants are typically black or dark brown in color and have a velvety texture to their bodies.These ants build large nests in trees, which can be up to several meters in diameter.The nests are made from a combination of plant material and the ants’ own saliva, which creates a strong and durable structure.

Tapinoma

Tapinoma are commonly found in urban and suburban areas, and are known to invade homes and buildings in search of food and shelter. They are attracted to sweet and sugary substances, and will often invade kitchens and pantries in search of food. They are also known to scavenge for food in garbage cans and other waste areas. They build their nests in wall voids, under floors, and in other hidden areas.

They can be identified thanks to their pair of antennae that are bent at a right angle, and their short petiole.

Formicinae

The Formicinae are a subfamily containing ants of moderate evolutionary development. Formicinae retain some primitive features, such as the presence of cocoons around pupae, and the presence of ocelli in worker. 9 genii can be observed in Lebanon.

Acantholepis

Tohme & Tohme studied with attention and grew colonies of Acantholepsis frauenfeldi, Acantholepsis Syriaca, Cataglyphis frigida. A. frauenfeldi tends aphids and mealybugs and feeds on their honeydew.

They are now gathered under the genus Lepisiota. They nest in rotten wood, in standing trees or in the ground, generally in less forested areas.

Camponotus

Camponotus is a very common genus. 17 species can be observed in Lebanon. Also called carpenter ants, theyr are known for their ability to excavate wood. Like termites, carpenter ants have strong mandibles, which they use to chew through wood and other materials. But unlike termites, they do not consume wood, but they build their nest inside it. On an ecological level, carpenter ants help to break down dead wood and other plant material, which helps to recycle nutrients back into the soil. All ants in this genus, and some related genera, possess an obligate bacterial endosymbiont called Blochmannia. This bacterium has a small genome, and retains genes to biosynthesize essential amino acids and other nutrients. This suggests the bacterium plays a role in ant nutrition.

Cataglyphis

The Cataglyphis, also known as Sahara Ant, is a genus of ant that is found in arid regions.

These ants are known for their remarkable ability to navigate through the harsh desert environment, using the sun’s position and polarized light to find their way back to their nests. Indeed, Cataglyphis spp. are to come out of their underground nests and forage at the hottest hour of the day, even if the midday sun is so hot that even the permanent residents, sand lizards, insects, and a few birds, have to take shelter. They can withstand higher temperatures than any other insects, and are able to survive in temperatures that can reach up to 70°C (158°F) by regulating their body temperature and behavior.

They pour out on to the sand and search for insects that have died of heat stress. They will often travel long distances from their nest in search of food, sometimes covering up to 50 meters in a single trip. Each ant dashes about in zigzag patterns, but as soon as one is lucky enough to find a tiny insect corpse, it has to get it back to the nest fast before the ant dies of the heat. It does not retrace the zig-zagging path of its outward journey; even if a scent trail made this possible, such a route would be time-wasting. Instead, it runs in a straight line directly back to its nest hole.

Sahara Ants are small in size, measuring only a few millimeters in length. They have a reddish-brown coloration and are covered in fine hairs that help them to retain moisture in the dry desert environment. These ants are also known for their long legs, which allow them to move quickly across the sand.

In Lebanon, 8 species were found.

Lasius

Lasius spp are also called “moisture ants.” They are a type of ant that is commonly found in damp environments. They are known for their ability to thrive in areas with high levels of moisture, such as in rotting wood or in soil that is constantly moist. This situation implies to be able to control the moisture levels in the environment, as too much moisture can lead to the growth of harmful fungi and bacteria. They do this by building intricate nests that are designed to regulate the humidity levels inside.This is important for the survival of the colony.
One of the unique characteristics of moisture ants is also their ability to create satellite colonies. These colonies are established in nearby locations and are connected to the main colony by a network of tunnels.This allows the ants to expand their territory and increase their chances of survival.

In Lebanon, 3 species can be observed. Among them, Lasius emerginatus, which tends aphids to feed on their honeydew.

Paratrechina

Paratrechina longicornis, recently introduced in all tropical habitats by human activities, is a pest. It is also called crazy ant, for its erratic and unpredictable behavior. Crazy ants are also known for their ability to cause damage to electrical equipment. They are attracted to electrical currents and can easily short-circuit electronics, causing damage and potentially starting fires.

One of the most notable characteristics of crazy ants is their ability to form large colonies with multiple queens. This allows them to quickly establish themselves in new areas and outcompete other ant species.

Plagiolepsis

Restless Ants, also known as the Red Ants, are reputed for their highly active and restless behavior, constantly moving around in search of food and resources.

Prenolepsis

Prenolepsis are also called winter ants. Unlike many other ant species, winter ants do not hibernate during the winter. Instead, they have developed a number of adaptations that allow them to survive in the cold.