Generality
The sand flies are arthropods of health interest belonging to the order of flies.
The sand flies - also known as sandflies - are insects with wings that are part of the large group of ectoparasites.
These Diptera are of medical interest because they are capable of transmitting various infectious diseases to humans and animals, among which the best known is undoubtedly Leishmaniasis.
Among the different species of pappataci present in Italy and possible vectors of parasites, viruses and bacteria, we recall Phlebotomus papatasi, Phlebotomus perniciosus and Phlebotomus perfiliewi .
In truth, even the dipterians belonging to the genus Lutzomyia are considered pappatacians and are also able to transmit leishmaniasis and other infectious diseases. However, this type of sand flies is mostly found in America, Colombia, Peru and other Western hemisphere countries.
Curiosity
The name "flebotomi" comes from the Greek "drip" and "temno" which means, literally "vein cutter".
The most common name "pappataci", instead, derives from the fact that these insects bite humans and animals to feed on their blood without emitting any noise (in other words, "eat" and "shut up"). Therefore, it is very difficult to perceive their arrival, unlike other insects such as, for example, mosquitoes that emit a typical high-pitched buzz.
Another very particular name attributed to the pappataci is that of "velvet insect".
Features
Main Characteristics of the Pappataci
The sand flies are insects, in some respects, very similar to mosquitoes and belonging to the order of Diptera. The females are hematophagous and this means that their nourishment is represented by the blood, in this case, both of man and of animals.
The adult specimens of sand flies are very small, about 1.5-3 millimeters, are yellowish in color and the whole body, including wings, is covered with a fine down. The eyes are large and black and the hairy wings have a lanceolate shape.
The sand flies are not able to fly against the wind, for this reason, they are not able to get far from the places where they reproduce. They are mainly nocturnal animals and love the warm climate, even better if associated with a certain degree of humidity. Not surprisingly, the sand flies are particularly common in all areas adjacent to the coasts, where the temperature is high enough to allow their survival.
In Italy, the pappataci are widespread especially in coastal areas, but can also be found in hilly areas and in all those areas where temperatures allow it. If, then, we think of the increase in general temperatures that has occurred in recent years, it is not surprising that the spread of these insects has increased considerably.
Life Cycle of the Pappataci
The female specimens of sand flies spawn about four days after a blood meal. For laying, the females of sand flies prefer dark and damp places, such as small cracks or fissures located on the walls of the cellars or on the walls of the wells, but they can also lay inside holes in the ground or in other quiet places.
Normally, thirty to seventy eggs are laid. After a period of about 6-12 days, the larvae of sand flies emerge from the eggs and are characterized by their vermiform appearance, black heads and gray bodies. The larvae are not hematophagous, but feed on plant debris, leaf mold and rotting waste.
In 30-35 days, the larvae of the sand flies face four molts and then turn into nymphs. Once this stage is reached, after 6-14 days, finally the adult form is reached.
Pappataci behavior
As mentioned, sand flies are preferentially nocturnal animals. During the day they prefer to be sheltered in dark and damp places, such as cracks in walls, burrows of other animals, under the foliage or inside barks. During the night, instead, the pappataci come out to feed, usually, of sugary substances and sap extracted from the plants. Females, instead, to reproduce and lay eggs must feed on blood, human or animal.
Adult sand flies, although with wings, are not skilful flyers and, for this reason, they cannot cover large distances to find a "victim" to feed on. In some cases, the flying style far from fluid of the sand flies is defined as "jumping".
Finally, let us remember that adult sand flies can spend their lives entirely outdoors, just as they can live inside homes (behind furniture, under mattresses, in cracks and fissures in walls and ceilings, etc.).
Pappataci Stings
The female sand flies bite humans and animals to feed on their blood, which is indispensable for reproduction and spawning.
As stated above, the flight of the sand flies is not the best and is "hopping", for this reason, more often than not, their bites are concentrated in the lower part of the body (legs, ankles, etc.).
At the time of the meal, it is difficult to realize the sting, however, the resulting macular-papular lesion is often painful and / or itchy . This reaction is triggered by the insect's saliva, which is injected when the meal begins.
In some cases, an erythematous form may also occur, probably due to an allergic reaction resulting from the puncture itself (ie, saliva) of the sand flies. In case of a skin reaction of this type, it is advisable to consult a doctor.
Transmitted pathogens
Diseases and Pathogens Transmitted by Pappataci Stings
As annoying and painful as the bites of sand flies may be, what is really worrying are the pathogens that can potentially be transmitted by these troublesome insects.
In fact, the sand flies are vectors of various parasites, bacteria and viruses that can cause infectious diseases - sometimes even very serious - in both humans and animals.
Below, therefore, we will see what are the main diseases that can be transmitted following the bites of sand flies.
Leishmaniasis
Leishmaniasis is most probably the most widely known disease of the sand flies. Leishmaniasis can affect both animals - and, in particular, dogs - and humans.
This pathology is triggered by protozoa (parasites) belonging to the genus Leishmania . The parasites in question enter the sand flies when they bite an infected animal and, again through the insect bite, can be transferred to other healthy animals, but also to humans (in this case we speak of zoonoses ).
Once the parasites have been transferred, they can cause leishmaniasis which - depending on where the protozoa are located - can manifest itself in different clinical forms:
- Cutaneous leishmaniasis : it is the most widespread form and occurs when the parasite remains localized at the level of the skin, at the site where the sand flies have their individual or animal point. The lesion caused by the pappatacio, in these cases, increases in size up to ulcerate inside.
- Mucus-cutaneous leishmaniasis : occurs when the parasite is localized at the level of skin and mucous membranes. It is characterized by the appearance of skin lesions and lesions of the mucous membranes of the oral cavity and nose.
- Visceral leishmaniasis : is the most severe form of leishmaniasis and - if not properly treated - can lead to death. The symptoms manifest slowly and involve different organs and systems.
Although leishmaniasis can cause severe symptoms in humans, in many cases the prognosis is good. However, this argument does not apply to animals and, in particular, to dogs. In man's best friend, in fact, leishmaniasis - especially if not promptly treated - can prove lethal.
Pappataci fever
Sand fever - also known as " three-day fever " - is another infectious disease that can affect humans following the bites of sand flies. Mosquito fever is caused by Arbovirus transmitted to humans through these insects.
Again, the virus enters the sand flies after beating a sick individual and can be transferred to healthy individuals following a new blood meal.
This disease occurs mostly in the summer months (this explains why it is also known as " summer fever "). The symptoms are flu-like and consist of fever (usually lasting three days), headache, weakness, muscle and joint pain, chills, dizziness and nausea.
Did you know that ...
The term Arbovirus derives from the English "Arthropod-Borne Viruses" and represents a vast and heterogeneous group of viruses that can grow both within arthropods and within vertebrates. Most of these viruses mostly affect animals and infect humans only occasionally, giving rise to so-called zoonoses.
Meningoencephalitis and Meningitis from Tuscany virus
Other infectious diseases transmitted by the bites of sand flies are encephalitis, meningitis and meningoencephalitis caused by the Tuscany virus . This virus - also part of the large group of Arboviruses - owes its name to the place where it was first isolated, that is the Tuscany region.
Infection with the Tuscany virus is associated with the onset of the aforementioned diseases of the central nervous system, especially in the summer months, a period in which the sand flies are more active and spread more easily. Normally, the meningitis caused by this virus is less severe than in other forms of meningitis, but this should not be underestimated. The symptoms include several symptoms, including fever, severe headache and neck stiffness.
Fight against the Pappataci
Useful Tips for Fighting Sand Catchers
Below are some useful tips to avoid the annoying bites of the sand flies and the potential contraction of infectious diseases transmitted by them. These are simple steps that can however be fundamental to avoid contact with these insects.
- Air and light all the rooms, especially in the summer. The pappataci, in fact, love warm, dark and humid places, therefore, light and fresh air are elements of strong disturbance for these insects.
- Install mosquito nets with a very dense texture . The pappataci, in fact, are much smaller than mosquitoes or other flying insects and, therefore, are able to pass through the meshes of common mosquito nets.
- Use appropriate repellents (available in sprays, wipes, sticks, etc.) to avoid the bites of sand flies.
- Repair any cracks or fissures on the walls that may represent an ideal daytime hiding place for the sand flies.
- If you have a garden, always keep it clean and well cared for, taking care to eliminate stagnant water, foliage and plant debris from the soil.
- If necessary, use appropriate insecticides to eliminate them permanently. The sand flies are sensitive to pyrethroids . Attention, however, to the use of similar products in environments where cats live, since these compounds are toxic to felines.
Useful Tips to Protect Dogs from Pappataci Stings
Since leishmaniasis transmitted to dogs by bites of sand flies can be fatal, prevention is of fundamental importance. Here are some useful tips.
- Vaccinate the dog against leishmaniasis.
- Use specific repellents against sand flies specially formulated to be applied on dogs. In this regard, we remind you that the use of these repellents is highly recommended even if the dog has been vaccinated.
- Limit the walks and the stationing of the dog outdoors in the twilight hours and at night, or in the hours when the sandflies come out of their hiding places to feed themselves.
- If possible, let the dog sleep at home.
