Ordering

Ants belong to the order of Hymenoptera. There are many species that cause various problems in urban areas, most notably Monomorium pharaonis (Pharaoh ant) and Lasius niger (black ant).

Biology

They live in organized colonies. Their nests are located on tree trunks or in the form of basements in the ground. In the nest live the queens that lay eggs, the workers, the larvae, the males and the hoplites (soldiers). They are all-variable (they undergo a complete transformation), ie their developmental stages are egg-larva-nymph-thriving. The queen is the largest ant in the nest and never goes outside. The queen appears during the mating season as a reproductive mating mat and for this reason, at this stage, it carries wings and flies out of the mother nest. During the swarm, many other ants follow her and build a new nest with the new queen. This is done only once a year in each nest, during the summer months.

Monomorium pharaonis

It is an ant with a small body. The workers are 1.5–2mm long and brown-yellow. They prefer hot and humid conditions, which is why in many areas they are confined to buildings. They have many queens in each nest. Workers in search of food leave the main nest with the brood, to form peripheral colonies when they feel threatened. They often “fill” the building. The biological cycle of this species does not exceed two months, while the queens live for several years.

Lasius niger

The workers are 2–5mm long and dark brown / black. Black ants make nests outdoors, on walls, under paving, etc. They travel long distances for food and water and usually enter homes, where fighting them is only necessary when they are a serious problem. The biological cycle of workers ranges from 50 to 70 days. A colony of black ants has only one queen and a few thousand individuals.

Health Significance

They can carry germs to clean areas as they come from afar and may have passed through litter or other contaminated areas. Many times they make nests in electrical panels and create problems.

Management Ways

Prevention: There should be no openings (eg open windows, openings under doors, etc.). Ants “invade” the building for food or water. We therefore keep food well packaged and sealed (eg in glass jars). One of the required actions is the cleaning of workbenches in food areas and dining rooms.

Monitoring: It is recommended to use feed traps to record their presence.

Treatment: In order to control the ants, direct sprays with contact insecticide are carried out in the nests, residual sprays in the places where we see them circulating while special non-toxic ant-killer gels (gel) are applied.