Friday, July 6, 2018

Life of in the Undergrowth: lots of bugs in the forests of Kanagawa Prefecture!



After breaking my right wrist, I had to concentrate my activities in forests not to actual maintenance works like thinning or mowing with powered tools, but to nature observation or to learning forest bathing. One of my friends told me, “Well, Naomi, it’s a kind of oracle from the goddess of mountain to reflect yourself with your broken wrist.” Er, OK. I’m recovering now and have started to join little by little summer mowing sessions in Niiharu and in the forests of Kanagawa Prefecture. Though, I noticed I now have a slightly different mind-set about my definition to have a fun in forests … unexpectedly to be honest. Before the incidence, I was like “Wow, keeping biodiversity in Japanese forests is really busy and hard works! We need more hands to complete weekend schedules for thinning (or mowing, or coppicing, or … pls. choose your pick). Busy, busy, busy.” Practically, I still think so, but … how should I put it? … I feel forests are different space from such city-rat mentality of “To Do List.” … Whatever humans do, it’s really difficult to force forests to behave according to our schedule. Yeah, we can enforce lots of yields or out-of-season harvests by applying chemicals or the like to veggies. But, of course, that’s not our forest volunteers want to achieve. Then, what? With my aching wrist, I realized a change in me when I saw insects.


Wonderful canopy of trees seen from a bridge
 over a deep valley in Tanzawa area
丹沢.
 So, birds are watching them always to spot food,
 like a caterpillar … really?


Till this season, I was not much aware of forest bugs around me. Yeah, butterflies flew before me a lot, or insect bites were weekend rituals these days. But it was just that. This spring, as I could not have worked with my saw for several months, I had lots of time in forests to see how moths behave, or the way Panorpa japonica ヤマトシリアゲ preys on the other insects (; it sucks bodily fluid of the other bugs by holding them tight … wow). I found simply observing them was fun! As both the City of Yokohama and Kanagawa Prefecture ask us to record the spotting of particular kinds of creatures in order to measure the condition of environment, it’s also like “hunting” them in forests. For this game I’ve learned we need to be strategic. In order to find Mnais costalis 二ホンカワトンボ with beautiful wings of reddish orange, we need to be near a gently flowing stream within a natural environment where the application of chemicals are minimum. To meet a chic Lethe diana クロヒカゲ, we have to enter a forest of substantial size without the record of marine transgression during interglacial period, like Tanzawa 丹沢 or Hakone 箱根. When there are many kinds of cockroaches which are different folks from the invaders to our kitchen, it’s a sign the forest is rich in biodiversity … Before powering up a chainsaw, let’s stop and look around. I could find a busy world of these creatures. Amazing.


Panorpa japonica in Niiharu Citizen Forest
Mnais pruinosa Yamamoto in a South Forest of Yokohama.
 Japan has 2 kinds of Mnais dragonflies,
 and Mnais pruinosa Yamamoto is for southern Japan.
 The North Forests of Yokohama has another,
  Mnais costalis which is for northern Japan.
  
i.e.  Kanagawa Prefecture is on the border
 of these 2 kinds of Mnaises
  
whose DNAs are different each other.
 Scholars for the Museum of Kanagawa Prefecture
 hypothesize they had a same ancestor long ago.
 During interglacial period
 when a much higher sea level created
 a complicated shoreline in present-day Kanagawa,
 the community of Mnais was divided accordingly
 and the species evolved to have different genes.
Vanessa indica in Tanzawa.
 It’s a common butterfly from India to the east, and so,
 the City of Yokohama designates them
 an indicator species which could imply
 the condition of natural environment in a city.
Ypthima argus in a forestry road of Tanzawa.
 They don’t like cities and
 we have to go to relatively clear forests of mountains.
Cradles of Attelabidae,
 made of leaves of Euptelea Polyandra,
 we found on a forestry road.
 Hey, any car of deer hunters can crash them!

Chubby Amata fortunei in Niiharu Citizen Forest


During forest instructor trainings, we’ve learned the objective of taking care of forests with chainsaws is to facilitate activities of non-humans in forests. Plants are the basis of forests; lots of plants mean lots of tiny creatures, like insects, birds, and the others, that can feed on them. Saws and sickles are to help plants to thrive and sustain living things that depend on vegetation. Then come those carnivorous ones, again insects, birds, fishes, animals … to eat the herbivorous things. At the end of the cycle is the sweepers in forests, like microbes, mushrooms, carrion beetles, … cleaning up the dead bodies of any of living things on the ground and make the soil rich for the plants to cover the floor … that’s the theory. Though, it’s easy for us to be into cutting trees or mowing grasses carelessly. It’s simply a fun to apply chainsaw, oh yeah. Meanwhile, forests have their own time no matter what. Wielding saws cannot change it, unless we end up with create a desert or destroy completely a mountain. So, human activity in a forest is like reciting Om always to keep a pace with the environment where so many caterpillars are munching fresh early-summer leaves and dreaming to molt soon … Hmmmmmmm, my tiny step to enlightenment, isn’t it? Maybe, the goddess of the mountain truly has given me the time to feel that with my bandaged dominant hand. Oh dear …


Lycaena phlaeas in early spring of Niiharu Citizen Forest.
 They lay eggs on Polygonaceae in an open field.
 i.e. Well-timed mowing by humans is important for them to thrive.
Mycalesis gotama in Niiharu Citizen Forest.
 They lay eggs in the bushes of Pleiblastus chino. If we too enthusiastically mow bamboo grass in a forest,
 they would be gone.
 Thankfully, they are ubiquitous for now …
 I think their understated bull’s eye patterns are chic,
 representing Japanese traditional rural life …
Two snails taking a nap
 on the back of a leaf of kudzu (Pueraria montana) … ZZZZZZZZ
Marks of spawning by white stripe long-horned beetle
 on Quercus serrata in Niiharu.
 Their caterpillars then dig further deep
 in the trunk eating the fresh of the tree.
 When they do this in commercial chestnut orchard,
 they are enemy of farmers.
 But they simply use old deciduous broad-leaved trees
 for their procreation,
 and hence contribute to forest regeneration
 when the forest is natural and healthy.
 Do we regard them nuisance? Or …
Lots of cecidium! Another sign of cradles for bugs.
Table manner of insects 😄
So sorry for out-of-focus photo …
 could you figure out a caterpillar of Lymantria dispar in the middle?
Whose baby is this?
This is cute!
 A tiny caterpillar of Kaniska canace on a leaf of Smilax china.
And his older brother in the same house of Smilax china in Niiharu.
 Hmmmmmmmmm …
 I’m entering into the world of ”Nausicaä of the valley of the wind” …


If you find a problem in Yokohama’s forests, please make a contact with

Office for the Park Greeneries in the North北部公園緑地事務所
Yokohama Municipal Government Creative Environment Policy Bureau横浜市環境創造局
Phone: 045-311-2016
FAX: 045-316-8420

Or

Office for the Park Greeneries in the South 南部公園緑地事務所
Yokohama Municipal Government Creative Environment Policy Bureau 横浜市環境創造局
Phone: 045-831-8484

FAX: 045-831-9389



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