Caution! Dangers in Forests of Yokohama: Wasps, or selfish humans

Wasps. The Lovers volunteers thinned the chamaecyparis obtusa and pisifera last March, near Zone C of Niiharu. In the process, we lopped off branches and simply piled them aside in the field in order to make logs easy to be trundled. The cut branches became a huge hedge that looked like a newly built wall from afar. Removing the logs and sweeping the field after the operation were not supposed to take 5 months. It did, in the end. (Er, volunteer work is once in a week, you know …) We completed the task this month, July, which means there was enough time for weeds to spread over the pile of branches. It became an ideal nesting ground for wasps. Woops. First, the neighboring landlord who’s doing farm work next to the pile complained that the spreading weeds started blocking the road he commuted every day. So one activity day in early July, aside from works to load the logs on a truck, the volunteers mowed the weeds invading the road a bit. Then, the menacing buzz came out. Wooooooow. “Get away!” A large tiger-stripe with wings appeared from a hole facing the road, and flying to sentinel around the pile. “Gee, we should have completed this job earlier …” “Anyway, stopgap measures! Return to the office hut to collect a spray insecticide.” July is in the early stage of nest building for wasps. Precaution could work. So, since then during the final phase of the operation, we treaded carefully around the pile of branches. Every time my seniors brought huge spray cans of insecticide whose label said “The range of emission: 10 m.” “10 m, really?” “Let’s do a trial.” “Ready, aim, spray!” “… 5 m, I guess.” “Is it effective?” “Well, better than nothing, I hope.”

An anti-wasp spray and a first-aid box are ready in the field.

Hm, this ad in a drug store says the spray will reach 11 m.

Anyway, we’ve moved all the logs, at last. Yayyyyy!

Basically, getting rid of wasps and other dangerous animals in private land is the job landlord must pay. The thinning operation was done in a private land next to the Citizen Forest, so that the City won’t pay for it. In addition, there is this huge pile of branches and boughs. The farmer who’s commuting every day to the field next to the pile thinks the “hedge” annoyance. The large pile must be disposed promptly as a trash produced in a private property, which could cost something. The amount is too large to be sneaked in household garbage for the City to collect. Disposing branches and other remnants after the forestry in metropolitan Tokyo area is becoming a huge problem. This Niiharu episode is not unique. The economizing landlord told the Lovers, “Please burn the pile.” “Hey, it’s very dangerous to set fire now. Did he ask it to our Chairman?” “Yeah.” “Wooooow.” Humid summer in Yokohama makes it difficult to watch if the fire is controlled. Besides, we are entering the months when the activity of wasps reaches to the max. Setting a fire could trigger “a wasp war.” The idea to deal with this problem became, (1) the Lovers will deal with the pile during winter when the activity of wasps are dormant, and the weeds can be controlled, and (2) the landlord of the thinned area must negotiate with his neighbor to wait until then; any possible cost during the waiting should be the responsibility of the landlord. A first-year newbie of me for Niiharu Lovers is holding my breath how the issue would be settled. The executive office of Lovers must mobilize intricate ability of diplomacy in the Niiharu community … civil-society based forestry has its own peculiar difficulty …

The weeds are approaching to the utility road …

An entrance to wasp nest

So, meanwhile, in this post I list the dangers you may encounter during summer in the forests of Yokohama. The first hazard I have to call your attention is, of course, wasps; in Japanese, Suzumebachi. They can kill you if you are bitten and have an anaphylaxis shock. On average 20 people died every year in Japan due to a wasp attack. Although we can find many “country hedges” made in situ in public and private forests these days, Niiharu Lovers seniors are now critical of this practice. The hedge made in this way is an ideal nesting place for wasps in Japan. “Now, how does the City think of this problem, huh?” The take-away in our episode is, please be careful when you find country hedges in the Forest of Yokohama. When unfortunately you meet one of them, never try to brush them off. Your movement shall be interpreted as a declaration of war for them. You stay calmly still while they are buzzing around you. Eventually, they conclude you are just passing by, and move on. When the coast becomes clear, you can start moving again. For precaution, we can purchase poison remover for about 1000 yen via internet, or in home centers, large drug stores, Tokyu Hands, and other places. This site explains how to use a kit available in Japan (in Japanese). When bitten, according to the advice of Wakayama Prefecture, (1) wash the affected area with running water. (2) Apply the remover to suck out the poison. (3) Apply anti-histamine. (4) See the doctor ASAP. If you are bitten once before, twice bitten could mean death within 15 minutes. Please be careful.

Poison Removers.
I found them in one of the special stores for mountaineering.

The next one which is easy to encounter is rhus javanica var. chinensis, Nurude in Japanese. It was used as poor peoples’ lacquer for wooden dishes. The similarity does not end here. Although it’s not as strong as sumac tree, many people can still react to them. If your toddler innocently touches them, you’d better wash their hand immediately with cold running water, and watch carefully for allergic reaction. If the situation worsens, go to see a doctor. Nurude is a pioneer plant so that harsh conditions of urban forest are a kind of their field. We can find them along a paved road in Yokohama Nature Sanctuary. Please be careful.

Rhus javanica var. chinensis.
The point to identify them is,
watch for the arrangement of leaves and the stems.
They have this orderly leaf-formation
with a kind of leafed stems.
They are very common in Yokohama Citizen Forests.

And of course, poison ivy. Japanese version has its own Latin name, toxicodendron orientale. They are also regulars in the forests of Yokohama. When they are climbing up trees, it is easy to recognize, but the distance can fool our eye. They often hide within the thick undergrowth. We are a sort of surprised to know how big their leaves are when we look at them close-by. It would be easy to touch them without recognizing. Better keeping the trekking road where the undergrowth is clear.

Young poison ivy in Niiharu

And they can hide within the vegetation under the tree.

I also have to mention artaxa subflava and euproctis pseudoconspersa. Actually, they are more common in urban small gardens and tree-lined streets in downtown Yokohama, especially when there are camellias. Their body, both caterpillars and adults, have small but numerous venomous hairs which can trigger allergic reaction for almost anybody. According to the advice from Health and Welfare Bureau of Yokohama, if you are stung by them, (1) wash the affected area with fresh running water, then (2) with the duct tape, try to remove the hairs from the body; never try to sweep them by anything other than strongly sticky tape. When you use your hand to remove them your hand will have reaction. Moreover, their hairs are tiny and light. They are easy to be blown away and inhaled, which could cause internal  allergic response.  (3) Wash the part again with running water. (4) Repeat (1)-(3), until the itches and swelling recede. (5) When the reaction continues or serious, visit the clinic.

Camellias are really common in all over Yokohama.
So, we must be careful for venomous euproctis,
especially during spring and summer.

And for anybody’s fear, there are poisonous snakes. In Japan there are 3 kinds of natives in this category: Japanese pit viper, rhabdophis tigrinus, and protobothrops flavoviridis. In Kanagawa Prefecture, we have the first 2 of them, but rhabdophis tigrinus are living in Tanzawa and Hakone. (Oh, by the way, Tanzawa and Hakone are called Okuyama, which means the mountains beyond Satoyama.) So, when you hike the area in Yokohama, Kamakura, or Miura Peninsula, the only snake business we have to be attentive is for Japanese pit viper. The first thing we must do is NEVER venture into the off–road. Yokohama’s forests have many damp grounds that can be covered by thick vegetation. Those are the places where Mamushi call home. Unless you know the ground really well, it is difficult to identify such sites just by looking. The locals who know the forest inside-out never dare to go inside the spots during spring and summer. Second, the vipers can also come out of their places to the trekking road. Our line of defense is noise. When we walk and make enough human noise in advance, such as sweeping noise by canes as we walk, timid vipers notice we are approaching and leave to avoid encounter. In case you are bitten, try to see the doctor ASAP. This newspaper article last year reported a research that found people running to the clinic for 18 minutes (average) after a viper encounter had a better result in treatment than those waited ambulance to see a doctor. Although running would hasten your heart beat and make the poison to circulate your body faster, laying in a mountain road waiting for emergency rescue makes the matter worse. It’s a matter of life and death, really.

Caution! Vipers are here!

In Niiharu, the left, viper, is dangerous.
But the right, Japanese rat snake, is harmless.
I’ve met rat snakes many times in Niiharu this July.

… But, really, no one knows if we encounter cobras or rattle snakes in the forests of Yokohama. It is an international port town. Currently, 40% of Yokohama’s vegetation is alien species. The poisonous foreign species could easily escape from the Container Terminals. In addition, this is the city more than 3 million urbanites live. Many commuting to overseas and could bring diseases such as Dengue or Zika. So mosquito and other insect repellent should be very useful in the forests of Yokohama. The traditional Japanese mosquito coil is the most popular. They are also effective to fend off common orthorrhapha whose bite can again cause allergic reaction.

An ignited mosquito coil can be portable within this container.

These are high tech version for mosquito coils.
With batteries, some can last 480 hours.

Lots of insect repellent in drug stores

But I think this organic peppermint oil is
the most effective among those repellents.
Caution, based on my experience:
NEVER apply it near your eyes.
I learned firsthand the reason
why it can ward off the insects …
its very minty vapor rapidly evaporates …
I cried, really. +.+
The peppermint oil spray is available
in sports gadget stores.

My peppermint spray. Inside the box is this tiny bottle.

Hmmmmmm … come to think of it, all of these cautions are for humans. Those “pests” must have their reason to cause problem on us … Do you know some temples in Kamakura do not equip mosquito coils or other equipment to kill pests. The monks think killing creatures is anti-Buddha. They use only organic repellents such as strong hot pepper water to be situated in a bottle at the corners. It is our responsibility for that huge pile of branches in Niiharu … In the end humans can be the most tricky to control in the forests in Yokohama, perhaps …

The City Office who’s in charge of execution of Green-up Plan is

Yokohama Municipal Government Creative Environment Policy Bureau 横浜市環境創造局

Phone: 045-671-2891

FAX: 045-641-3490

http://www.city.yokohama.lg.jp/kankyo/