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🏥 | Ixodidaes are not the only “poisonous insects” to watch out for in the outdoor boom

Be careful at the photo camp (photo is an image)

Ticks are not the only "poisonous insects" to watch out for in the outdoor boom

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If you notice Yamabir, don't hesitate to peel it off your skin and rinse the wounded hirudin with clean water.

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 Daily Gendai Healthcare

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Yamabir(Yamahill, mountain leech, scientific name:Haemadipsa zeylanica japonica) IsHillA kind of.Terrestrial animal, large in the mountainsmammalianTo attack.Human capitalI often get there, so I hate it very much.


Yamabir is a land-dwelling leech and is the only terrestrial leech in mainland Japan as a blood-sucking leech.There may be multiple species outside of Japan.In addition, although the Japanese name with Japanese Yamabir has been proposed for stricter strictness, it is often called Yamabir, and this will be described in this section as well.It lives in the forests in the mountains, and it is one of the common wisdom that it is often found in humid places, and it has been talked about with fear in connection with deep forests.For example, "Takano』Depicts a scene where a" terrifying mountain frog "falls from the top of a tree.Originally inhabited in the mountainsDeer,boarHowever, the habitat was expanded as these animals began to appear in the satoyama.[1].

Blood was sucked without being noticed, and the woundBlood-sucking insectsThere is a strong disgust, such as being larger than that and having a slimy body. Some say that it is one of the most unpleasant animals for humans.[2]..But more damage, for exampleParasite,PathogenThe propagation of is not known.

Become active in a humid environment[3]..Sensitive to dryness[4].

Distribution and classification

in JapanIwate-AkitaSouth ofHonshuからShikoku,KyusyuIt is distributed in.Also aroundislandsThen.Sado Island,Mt. Kinka,Awaji Island,in additionYakushimaIs known.However,KanagawaAccording to the survey report, Shikoku is a distribution area, but there is no reliable information.OverseasChugoku OfYunnanAlso known as a habitat.The original name variant isTropical zoneIt is widely distributed in.Ryukyu IslandsButIshigakijima,Iriomote IslandMany, this isSakishima Yamabir H. zeylanica rjukjuana Is said to be.BesidesTokyo(Volcanic islandsIwo JimaToIwo Jima Yama Building H. zeylanica ivosimae Is known.However, there are some disagreements about these classifications, and there is also a theory that Japanese variants are independent species.


25-35 in length mmIt expands and contracts violently, and it expands to about twice.According to a report from Kanagawa prefecture, it is said to be elastic and durable, not torn when pulled, and not crushed when stepped on.[5].

The body is wide at the back of the center and narrows back and forth, but it is roughly cylindrical and slightly flattened on the back of the abdomen.It is roughly brown and has a maroon vertical line pattern.There are many small hump-like protrusions on the back surface.The body is divided into small body rings, but the actual number of body segments is several.There is a pair of round eyes protruding from the second to fifth sections and the back of the eighth section.There is an ear-shaped protrusion on the posterior side.SuckerIs at the front and rear ends, and that at the rear end is much larger.The jaw in the mouth has fine teeth.The anus is on the back of the posterior sucker[6].


In fine weather, it hides under the fallen leaves on the ground and stays still, but when a large animal approaches it, it comes out or climbs the grass to stretch its body and stand upright, swinging its tip around.Animal approach is in the organs around the suckercarbon dioxide,heatIt is supposed to be sensed by (body temperature) etc.[1].

As soon as you touch the animal, it attaches to you, and with the front and rear suction cupsInchwormIt moves like this, attaches to the soft part of the skin, and begins sucking blood.In generalDeer,boarIs the main host.otherAsiatic black bear,Hare,Raccoon dog,Japanese serow,Japanese macaqueIt has been confirmed that blood is also sucked.Yamadori,pheasantHas also been confirmed to be a target for blood sucking.

If you are a human, you may get inside the clothes and suck blood.SocksFor example, if the eyes are coarse, the head may be thrust through the gap to suck blood.There is also a measurement that it takes 30 seconds for something attached to the caravan shoes to slip into the socks.[7]..When it rains, the activity becomes even more active, climbing up the tree, hanging from the tips of the branches and leaves, and sticking to the higher parts of the animal.Vinyl kappa is easy to stick, so it takes about 1 minute to climb from your feet to your neck.[8].

When sucking blood, the jaw in the mouth on the suction cup on the tip side first breaks through the skin,Blood coagulationInhibitHirudinInject the ingredient.It sucks blood until it is full in about 1 hour, during which it drains water and concentrates its components.It is difficult for the sucked side to notice that blood is being sucked[1].

When they are full, they separate from the animals and fall to the ground, hiding under fallen leaves.Often after sucking bloodMolting, Spawn.

Weak to dryness, but the temperature is 10If it is above, the activity is possible, and there is an activity except winter.Boso PeninsulaThen, activity is seen from April to November, especially during the rainy season and autumn rain.[8]..In addition, it does not go into the water by itself.

Life history

Parents lay eggs about a month after sucking blood.Eggs are wrapped in a transparent egg sac (cocoon) with honeycomb-like protrusions on the surface.This is a gelatinous foam at the time of spawning, and leeches spawn in this.When this foam dries, it becomes a transparent film.The interior is yellow and beautiful, and even says, "Everyone recognizes it as mysterious."One egg sac contains 1-5 eggs.In addition, the number of egg sac that one female makes in her lifetime reaches 6 or more.It takes about a month to hatch.incubationImmediately after, the larva is about 5 mm in length.According to the results of the breeding survey, the larva becomes an adult capable of spawning after 3-4 times of blood sucking, which takes about one year.It is necessary to suck blood once every 1-1 months until it becomes an adult, but after that, it is enough to suck blood once a year.Adults endure two years of fasting.He sucks blood a lot in his life, about 6 times.The longest lifespan in captivity was 1 years[9].

HermaphroditeIn Although,MatingI do. The two individuals mate as if they were strangling each other.

Growing environment

Generally inhabits mountain forests, especially moist,Mountain streamMany can be seen in places with a lot of moss along the road.Geographical distributionHowever, the habitat in each area was narrow and limited, and it was not found everywhere.

But more than that, it depends on the habitat of large mammals to be sucked, and sometimes it is encountered in open areas or even in small bushes.Although it is remote,Nara Park OfKasuga ShrineThere are many such things, and sometimes I sneaked into the bushCoupleWas seen rushing out while shedding blood.

However, from around Heisei, it has been said that the number of Yamabils will increase here and there.For exampleBoso PeninsulaThen around 1975KiyosumiyamaWhat only inhabited the area centered on the area spread to the north, south, east and west, and its habitat area increased about 2005 times in 30.[10]..In addition, examples of appearance in urban areas have come to be reported.Tanzawa area,Seino,Suzuka MountainsIn mountainous areas such asHikerEtc. are suffering from blood sucking[11][12].

This is consistent with the fact that deer and other animals have increased in the vicinity of human settlements.Masao Yamanaka (2007) also mentioned the commonality with the expansion of the habitat of deer, citing "the leeches from deer droppings" as the words of the elders in the area, and arguing that the deer are also responsible for the transportation of leeches. ..The reality is thought to be the parasitism of leeches on the hooves of deer and antelopes.[11][13].

Kenji Umeya states that another cause may be the increase in tourists entering the habitat.According to Umetani, when mammals are sucked blood frequently, antibodies are produced, and leeches that suck blood with antibodies die, which is thought to have the effect of suppressing the number of leeches.On the other hand, many tourists who did not have the opportunity to come in contact with the leeches may have allowed the leeches to grow without being blocked by antibodies.He also points out that the leeches may have fallen when humans attached to the leeches moved out of the habitat, leading to the expansion of the habitat.

In Kanagawa Prefecture, many blood-sucking damages have been reported even in residential areas adjacent to Satoyama.[1].

Place name derived from hill

Harm and response

The amount of blood sucked at one time is 2-3 for adults who lay eggs.mlIs.However, since bleeding continues after that, the amount of blood loss will be slightly higher than that.

Even if you are bitten, you will not feel much pain because the saliva of the leech contains an anesthetic component.The bite scar becomes a small round wound, and hirudin, which inhibits blood coagulation, does not stop bleeding for a while.Bleeding usually continues little by little for about 2 hours.Even if it stops once, it may bleed again due to bathing.After that, the wound heals slowly, and in extreme cases it can last up to two years.[14].

In addition, severe itching is likely to occur and may last for nearly a month.[15].

If it gets on your skinalcoholIs effective, and even if you bring it closer, it will fall.others,TueOrsalt,SalinityHigh liquid,VinegarlikeAcidic OfliquidIt is also effective to apply.There is also a preventive measure to wrap a cloth soaked in saline solution around your neck.[15]..It is said that blood-sucking marks should be stopped from suppuration.The parasites and pathogens transmitted by Yamabir are unknown.

Ointments such as antihistamines are effective against itching, but drugs containing ammonia may aggravate the symptoms.[15].

Due to the increase in the number of people in recent years, control with drugs has been carried out, but there is no decisive factor so far.For Yamabir only in JapanDietUsedInsect repellentIs commercially available.Also, taking advantage of its sensitivity to temperature changes, and L-mentholA repellent that contains DEET as the main ingredientThe Graduate University for Advanced StudiesWith an assistant professorAkita Prefectural Kinshi Agricultural High SchoolIs being developed by the students of[16].

AbandonedWooded areaLet's reduce the humiditySatoyamaIt is thought that the maintenance as a deer and Yamabir measures will be taken.[12]..Also, in some places, there is a bottle of salt for exterminating Yamabir at the entrance of the hiking course.

NigariCan be eradicated by spraying a coagulant using[17].


[How to use footnotes]
  1. ^ a b c d “Watch out for hiking and blood-sucking leeches, itching without stopping blood”. Nihon Keizai Shimbun (Nikkei Inc.). (October 2013, 7). https://style.nikkei.com/article/DGXDZO56792380Z20C13A6MZ4001 2019th of February 10Browse. 
  2. ^ Yamanaka (2007), p. 43
  3. ^ Kanagawa Prefecture Yamabir Countermeasures Joint Research Report
  4. ^ Be careful of Yamabir, Kanagawa Prefecture!
  5. ^ Kanagawa Prefecture Yamabir Countermeasures Joint Research Report
  6. ^ This chapter is by Uchida (1965)
  7. ^ Umetani (1994), p. 255
  8. ^ a b Yamanaka (2007), p. 44
  9. ^ The previous chapter and this chapter are mainly by Yamanaka (2007).
  10. ^ Yamanaka (2007), p. 45
  11. ^ a b "Outline of the 18 2nd Municipal Mayor's Roundtable on Regional Agricultural Policy". Ministry of AgricultureKanto Agricultural Administration Bureau. 2012th of February 11Browse.
  12. ^ a b "Satoyama maintenance as a measure against deer and mountain buildings (PDF)". Ministry of the Environment. 2012th of February 11Browse.
  13. ^ Iwate Daily2011/1/10
  14. ^ Umetani (1994), p. 258
  15. ^ a b c “Watch out for hiking and blood-sucking leeches, itching that doesn't stop blood (2)”. Nihon Keizai Shimbun (Nikkei Inc.): p. 2. (January 2013, 7). https://style.nikkei.com/article/DGXDZO56792380Z20C13A6MZ4001?page=2 2019th of February 10Browse. 
  16. ^ Developed by high school girls, leeches spray ... Released in June [Broken link]- Yomiuri Shimbun
  17. ^ Yomiuri Shimbun Tochigi edition July 2017, 8 7 pages.


  • Kaname Uchida, "New Japan Animal Encyclopedia [above]", (1965), Hokuryukan
  • Kenji Umeya, "Outdoor Poisonous Insects and Unpleasant Insects", (1994), National Rural Education Association
  • Yasuo Yamanaka "Yamabir (Haemadipsa zeylanica japonica): Japan's only terrestrial blood-sucking building (<series> Dangerous creatures in the forest 7)" "Forest Science: The Japanese Forest Society Bulletin" No. 51, Japan Forest Society, October 2007, 10, pp. 1-43, NOT 110006474230.
  • Kanagawa Prefecture Yamabir Countermeasures Joint Research Promotion Council, "Yamabir Countermeasures Joint Research Report", (2009), Kanagawa Prefecture

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