More and more people are struggling with a strange type of mosquito bite, which are usually a little more unpleasant than the usual mosquito bite and appear in places that are rather untypical for mosquito bites. These bites are usually from the autumn grass mite, which has been reproducing quite a bit recently (presumably as a result of climate change). Here’s what you can do about grass mites and their bites.
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How the autumn grass mite meets humans
Autumn grass mites belong to the family of running mites, the trombiculids, arachnids related to ticks. The larvae of these grass mites live parasitically, like the larvae of many other running mites.
They appear increasingly at certain times and under certain conditions, here in Europe their population increases every year in the late summer months from July to October. The autumn grass mites can then be found in large numbers in their typical habitats, in gardens, meadows, fields and on the edge of the forest. They mainly sit on leaves and grass near the ground and on the ground, because grass mites love (need?) A high humidity of at least 80%, which is more likely to be found near the ground. Therefore, autumn mites are usually not found higher than 20 to 30 cm above the ground, but unfortunately exceptions confirm the rule here as well.
Because the autumn mites have a strategy for getting to their hosts: the female mite first lays three to four hundred eggs in a moist soil. The larvae hatch from these and they want to go “high up” as possible. They first work their way up to the surface of the earth and then try to start the host search from the highest point they can reach. At these elevated points, on the tips of grass and other scalable, smaller plants or on mounds of earth, the larvae collect and wait in mostly tightly packed clusters until a host comes by and strips them off. The right host is actually a small rodent or bird, but the autumn mite larvae do not pay very close attention to who is shedding them, and so they quite often land on humans.
If the humidity is high enough, the grass mites are already active as soon as the temperature rises above 10 degrees, but they really perk up at temperatures between 25 and 30 degrees, which is why August and September are “their” months for us.
It is not entirely unlikely that you will get autumn mites in your garden and that your neighbor one piece of land further has his own peace and quiet. Because the mite populations adapt very quickly to the presence of a certain host, so if you have a certain small mammal, a kind of “island of autumn grass mites” forms in your garden, while the neighboring property remains free of autumn mites. But what should not be a reason to kill off all life in your garden, the increased occurrence of running mites is also subject to an unexplored change in time and changes with the macro- and microclimatic conditions, and a mass occurrence in a certain area almost never takes longer than two months.
The popular names of the autumn grass mites tell us quite clearly what the mite does to humans: The autumn grass mite is also known as harvest mite, hay mite, autumn louse, grass louse, ground louse or peach louse, and that is because they cause so-called harvest scabies in humans. What exactly that is, you can read below, in any case it itches a lot.
Tracking down autumn grass mites
It is not very easy to determine whether or not many autumn mites have settled in your garden. You will certainly not notice the female mites that lay their eggs underground, nor the larvae that then come up to the surface of the earth: They are tiny, 0.2 to 0.3 mm, which is smaller than some Needle point. In fact, they are so small that you usually do not even notice them when they are wandering around on your body, but only when you notice the first skin reactions, and by this time the larvae have long moved on …
If you have strange mosquito bites and you suspect that a fat colony of autumn grass mites has developed in a certain place, you still don’t need to go hunting with the microscope, you could try the following trick: Simply put a piece of white paper on top of it Bottom and wait a while, the paper is supposed to attract the animals, and since they are quite bright orange-red on an empty stomach, you will at least see an orange tinge.
Fight autumn grass mites
However, if you do this detective work with the intention of taking concerted action against the autumn grass mites, you can save yourself that: the grass mites cannot be fought effectively – chemical pesticides that only the autumn mites and not all possible beneficial insects and / or kill plants in the vicinity do not exist. An application of the widely scattered, ecologically incompatible chemical agents would also be of no use, with them a successful mite control could never be carried out (if your pest controller claims the opposite, you should ask him for verifiable proof).
Incidentally, the use of insecticides is also prohibited under the new Plant Protection Act, because what does not help in a targeted manner may no longer simply be distributed in the environment today. What is your luck financially: Even if the autumn grass mites have settled like islands, areas are usually affected where a chemical use would cost a lot of money.
So before you dump your yard just to kill a few grass mites, you’d better use smarter strategies to avoid nasty itchy spots. Here are a few suggestions:
Fighting autumn grass mites properly means prevention
Correctly combating autumn grass mites therefore means using the right preventive strategies, and there are a few of them: If you brought the bites with you from a walk rather than from the garden, you should simply choose other routes until winter and avoid the infested area.
The following protective measures can reduce the likelihood that the mites “can land on you”:
- Mites are late risers, and those who like to tinker around in the garden early in the morning are less likely to be attacked
- Wear thick shoes and long trousers when gardening and walking, and pull the stockings over the trousers
- You can spray arms and legs with one of the usual repellants such as Autan (active ingredient Icaridin)
- You could also spray your clothes with a repellent up to knee height, this should help for around five hours
- These clothing repellants usually contain benzyl benzoate, dimethyl phthalate or diethyl toluamide)
- Insect spray with natural or synthetic pyrethrum extract should also help to keep the mites away
- However, all of these agents are not harmless, by no means suitable for frequent use and are potentially dangerous for allergy sufferers
- A good idea is sure to smear the repellent on the legs of the deck chair (if you don’t breathe it in on the deck)
- The tip to take a good shower after staying in a potential mite area is also rather harmless
- Taking a vitamin B complex is said to produce a body odor that mite larvae do not like
- But please talk to a doctor beforehand, who will tell you if and when you can overdose on B vitamins
It is not entirely clear whether general strengthening of the immune system will help to reduce the response to a grass mite bite. Researchers observe that some people are preferred to be stung, while others are not stung even when the autumn grass mites are very abundant. Desensitization processes, in which the immune system develops antibodies, may be responsible for this. On the other hand, sensitization processes with increased reactions in the event of re-infestation are also observed … Here it was suggested to examine whether the people who react more sensitively belong to the increasing mass of people whose immune system is already seriously damaged by excessive hygiene and constant use of critical chemicals.
That would mean for you: If you were allowed to “enjoy” enough contact with potential pathogens in your childhood in order to develop a stable immune system, you can probably look forward to a bite from the autumn grass mite with serenity. If this is not the case and your immune system is already reacting to many environmental factors with an inadequate immune response (= allergy), you should read the following section carefully:
How the autumn mites harm people
This is how it goes in detail when the mite hits humans (for all hobby filmmakers who are still looking for an imaginative template for their next horror film): The larva has landed on humans from its “general hill” and is now walking on him for a while (unnoticed).
Because she is looking for a nice spot to pierce, presumably she is aiming for high air humidity, she finds such regions in people wherever they sweat or where clothing is tight (but maybe it just goes according to where the skin is so thin is that she gets through). Whatever the case, when she has found a pleasant place, she bites her epidermis, injects a little tissue-dissolving and anticoagulant saliva and soaks up the cocktail that has been mixed in this way.
Since it is so tiny, we don’t notice that either, in a favorable place it is often so long that it deepens and hardens its branch canal with another saliva component to form a kind of well. The autumn mite now uses it like a kind of elongated proboscis to get a little more out of us, this time from deeper skin layers. In addition to personal sensitivity, this “suction depth” is certainly another explanation for why people react very differently to the bites.
And they do, from person to person and from body part to body part other skin reactions are possible. Some people develop crusts on their legs and pustules in the waist region, other blisters or scabs, there is also eczema or spreading ulcers – or just animal itching that disappears on its own after a while. If you orient yourself to the popular name, the simple itching seems to be the most common symptom, otherwise you would certainly not call this reaction so harmless as gooseberry disease, harvest scabies or autumn bite. Most of the symptoms of these dermatoses, which doctors call thrombidiosis or thrombiculoses, should show up no later than 24 hours after the larvae have dropped off. Most of them should be gone after less than two weeks,
Treatment of the autumn grass mite – own and medical
If you develop reactions that cannot simply be ignored, there are a few tips to start with for self-treatment:
- Warmth in the bed in the first few hours is said to increase the harmful effect
- You get at least 70 percent alcohol and rub it into the bites, then the itch should go away for a few hours
- Oak bark extract and zinc shaking mixture (pharmacy) are also supposed to relieve the itching
If the skin reactions are so severe that you would rather put yourself in the hands of a doctor, he or she may prescribe an anti-pruritus drug (relieves the itching), or a mildly sedating ointment or an antihistamine. In the case of particularly severe itching, an emulsion containing cortisone may be prescribed; in the case of infections that go beyond the actual sting, an antibiotic ointment may also be prescribed.
If you are more often exposed to autumn grass mites and would like to spray yourself beforehand, this prevention with repellants should also be discussed with your doctor and compared to the possible side effects of these agents. Because all repellants are basically poisons, including the pyrethrum extracts obtained naturally from chrysanthemums, and anyone who has read about insect repellants on the Stiftung Warentest website how quickly some of these agents can cause nerve damage, including brain damage and seizures, is no longer completely ignorant use a spray can or cream.