The Mountain Pine and the Neotrombicula autumnalis
Did you return from a day in the Dolomites and now experience itching after a mountain hike on your skin? Were you walking among mountain pines? You might think it’s a spider or some insect bite, but chiggers most likely cause it!
Neotrombicula autumnalis, known as the “harvest mite” or “chigger,” is a tiny, aggressive mite from the Trombiculidae family. Found in various regions of Italy, like Tuscany, Gargano, and the provinces of Matera, Benevento, and the northeast, this mite is known for causing skin irritations, particularly during autumn.
The Trombiculidae family also includes other tiny parasites, such as berry bugs and harvest mites, which cause itching and irritation, especially during peak agricultural seasons.
Technically, chiggers are not insects but arachnids related to spiders, ticks, and scorpions. To distinguish them from insects, count the legs: insects have six, while arachnids, like chiggers, have eight.
If you’re experiencing severe itching, it could be due to chigger bites, often called “chigger dermatitis.” Chiggers are parasites, feeding off a host to survive. When they come into contact with human skin, they create tiny irritations that resemble insect bites.
The mites prefer a warm and humid environment, and they thrive in the Dolomites, especially in the mountain pine thickets. Chigger larvae attach themselves to humans as they brush past plants and shrubs during hikes.
Interestingly, chigger larvae don’t bite or suck blood. Instead, they use their mouths to pierce the skin and inject saliva enzymes that dissolve skin cells. The larvae feed on this liquid through a hardened tube formed in the skin called a stylostome.
In regions where chiggers are common, locals know the painful skin reactions caused by these mites and avoid walking among mountain pines in autumn when chiggers are most active.
People often get chigger bites while walking through bushes or tall grass at the edge of forests. Hikers, forest workers, hunters, and mushroom foragers are especially at risk. Chiggers are resilient but cannot infest humans unless they come into direct contact with bare skin. Chigger dermatitis only occurs through direct contact between the mite and the skin.
Chiggers are sensitive to temperature. They are most active in the afternoon when the ground temperature is between 19 °C and 30 °C. Below 15 °C, they become inactive, and at six °C, they die.
Only the larvae cause itching and are parasitic to animals and humans. The adults and nymphs live freely in the soil, feeding on plant fluids or insect eggs.
Uman skin reacts to chigger bites with red, itchy welts or a rash in areas where the mites have attached. While chiggers don’t transmit diseases, the itching they cause can last for over a week.
Chigger larvae are reddish-orange and about the size of a pinhead. They typically attach to exposed skin areas, such as the legs and feet, or other areas in contact with the ground, like the head or abdomen, when lying on grass.
Chiggers tend to bite in areas where clothes fit snugly, such as the tops of socks or the waistband of underwear. So, if you notice a rash in these areas after a hike, chiggers might be the culprit. The bite is not felt immediately, but the itching starts after 1-3 hours.
Preventing Chigger Bites
Prevention is better than cure. To avoid chigger bites, wear long clothing, avoid rubbing against vegetation, and don’t sit or lie on grass. Sun-exposed rocks are safe spots to sit away from chiggers.
Using insect repellents on your skin can help prevent chigger bites. Products that repel mosquitoes and ticks also work against chiggers.
Chiggers are particularly sensitive to sulfur, which can be a valuable ally against them. Sulfur powder, known as sublimated sulfur or flowers of sulfur, should be applied around the edges of pants, socks, and boots.
If you are in an area potentially infested with chiggers, it is also advisable to spread the powder on the skin of your legs and arms. To reduce the smell of sulfur, you can mix it with talcum powder in equal parts.
Keep in mind that sulfur has a strong odor, and when combined with sweat, it can become unpleasant. Additionally, it may irritate the skin of some people; if you have never used it before, it is recommended to test it on a small patch of skin.
After returning from a mountain hike, it’s essential to wash your clothes (at least at 60 °C – 140 °F) and take a hot, soapy shower. This helps remove any larvae on your skin before they bite and those that have already attached.
Treatment
Chigger bites are not contagious and do not spread from person to person. Treatment involves antiparasitic creams and corticosteroids. Sometimes, oral antibiotics are needed. If you’re bitten and feel intense itching, antihistamine or cortisone-based creams can help soothe the area. However, these treatments only alleviate the symptoms temporarily. The itching subsides only once the body eliminates the stylostome left by the chigger.
Summary:
A chigger is a mite that lives on vegetation in bushes. This bothersome parasite is also known as the biting mite. If you experience itching after a mountain hike, it is most likely caused by chiggers.
Trombiculosis is an infection caused by chiggers. Only the larvae of chiggers cause the irritating itch and are parasitic to animals and humans. Trombiculosis appears as small skin lesions similar to insect bites.
The only remedy is the use of antihistamine medications or corticosteroid creams.
The stylostome is the feeding tube used by the mites.
