They are small, wingless insects belonging to the order Siphonaptera.

The best-known species of fleas belong to the Pulicidae family and are the following:

Human flea or Irritant flea (Pulex irritans), the most representative species.

Cat flea (Ctenocephalides felis),

Dog flea (Ctenocephalides canis),           

Poultry flea (Echidnophaga gallinacea), remains permanently attached to a host.

Northern rat flea (Nosopsyllus fasciatus),

Oriental rat flea (Xenopsylla cheopis).

They are parasites that feed exclusively on the blood of humans, mammals and birds. Their bites are very annoying, they are hosts for parasites and transmit pathogenic microorganisms responsible for serious diseases, which is why their proper control is essential.

They are 1.1-4 mm long, oval in shape, laterally compressed to move easily through the hair of their hosts, and brown to black in color. Their antennae are short and their mouths have sucking organs to pierce the skin and suck blood. Their hind legs are longer than their front legs, allowing them to jump 200 times their length.

They have a hard body to withstand pressure and are covered with hairs/spines that facilitate their movements on the host. Their eggs are initially pearly and turn yellow and the legless larvae are light brown in color with chewing mouthparts. The larvae weave cocoons for pupation.

The female insect lays her eggs in dark places with , in accumulated litter in the host's dwelling (in nests of rodents or other wild animals, in stables or houses of domestic animals), in corners of houses with dust, in cracks or crevices in the floor or in the soil. Some eggs may fall on top of the host animal.

It lays 3-25 eggs per day or after each meal, repeating this process hundreds of times in its life. The ideal conditions for development are 18-27°C and 70% humidity.

The eggs hatch in 2-15 days depending on the species and conditions. The larvae avoid light, are lively, feed on various organic substances, excrement, feces and take refuge in cracks, crevices, etc.

The larval period lasts 10-20+ days. The larvae then pupate in a cocoon for 7-14 days before the adult insects emerge. If there is no host in the area, the adult does not emerge from the cocoon, and can remain alive for up to a year. The stimulus for emergence can be oscillations from the host's movements, an increase in CO2 or an increase in humidity.

Adult parasites feed on blood from the host. Their saliva helps in absorbing the blood. Females begin to give birth 3-4 days after feeding. The total life cycle can last from 2-3 weeks to 20 months.

Health importance

Although fleas can be a problem year-round, their population typically increases about 5-6 weeks after temperatures rise.

The absence of adult fleas on the animal does not mean their absence from the living space, as the eggs and larvae are there and continue their life cycle.

Flea bites are annoying, causing pain, itching, and skin reactions such as redness, swelling, and black spots. The intensity of the reaction varies. In addition, they can cause irritability and insomnia.

Fleas are intermediate hosts for many parasites and can transmit dangerous diseases such as plague, typhus, encephalitis, pseudotuberculosis, brucellosis, salmonellosis, etc. from sick animals to humans.

In cases of frequent infestations, hallucinatory parasitism can occur, a condition where the patient feels bites and sees fleas without them actually being present.

Similar symptoms may have causes other than arthropods. When there are no arthropods involved, the condition is called “hallucinogenic parasitism” and should be treated by health professionals.

The role of the entomologist is to determine if it is insects/mites, to identify them and to suggest ways of combating them. When there is no insect involvement, he must convey this in a discreet but firm manner and urge the “sufferer” to visit a doctor for further investigation.

Prevention:

Control of rodents that may carry fleas

Avoiding the supply of manure from suspicious livestock facilities

Preventing stray animals from entering the premises or caring for them as pets

Regular check-ups and care of pets (grooming, use of repellent collars, etc.) based on veterinarian instructions

Thorough vacuuming of all corners and hidden areas

Insecticide application:

Use of insecticides that also contain growth regulators to combat larvae

If regulators are not used, repeat spraying after one week.

Identification and treatment of infestations (e.g. stray animal nests)

Spray on all surfaces of the affected area