November 2005


It’s autumn and there are lots of big beautiful spiders all over the place. Some of their webs are truly amazing in size. Here are a couple of common species:

Nephila clavata
Tetragnathidae:
Nephila clavata (jorou gumo)

Argiope bruennichii
Araneidae:
Argiope bruennichii (nagakogane gumo)

Website: Common Spiders of Japan:
http://www.cyberoz.net/city/sekine/zukax.htm

I was looking for beetles under the bark of a rotten tree when this long-legged centipede ran out = quite a surprise! I guessed it was harmless enough so I caught it and took a few photos. Later found out that it is sometimes known as a house centipede (geji) and some people regard them as beneficial creatures because they eat things like cockroach nymphs. However, with its long legs and high speed, I think most people would try to squash it if they saw one in their house!!
Thereuonema tuberculataThereuonema tuberculataThereuonema tuberculataThereuonema tuberculata

Myriapoda: Chilopoda
Scutigeridae
Thereuonema tuberculata
(geji)

Found a group of more than 20 rove beetles (family: Staphylinidae) under some straw at the edge of a rice field. This species is probably Paederus fuscipes (aobaarigatahanekakushi).

“Staphylinidae are one of the largest families of beetles, with over 45,000 species known worldwide and probably over 75% of tropical species still undescribed.” (From University of Florida Institute of Food and Agricultural Sciences:
http://creatures.ifas.ufl.edu/misc/beetles/rove_beetles.htm)

Paederus fuscipesPaederus fuscipesPaederus fuscipes

Coleoptera: Staphylinidae
Paederus fuscipes
(aobaarigatahanekakushi)

This oil beetle (tsuchihanmyou) was sitting on my doorstep when I came home last night. As you can see in the first photo, it played dead when I first picked it up.

Oil beetles are fascinating insects, and not just because of their unusual appearance (short elytra exposing most of the abdomen). They contain a poison (cantharin) in their hemolymph, which exudes from their leg joints when they are handled, and this substance causes skin blistering in humans (link to image), so these insects are also known as blister beetles. The same chemical (but extracted from other species) has been used for centuries as an aphrodisiac (spanish fly ointment) and is contained in wart removal products.

Another interesting point about the oil beetle is that it is parasitic on small solitary bees (hanabachi). The very active beetle larva (known as a tringulin) waits in a flower for a bee to visit, then clings onto the bee’s leg and gets carried to the nest, where it feeds on the bee’s eggs and store of pollen. For more information on the oil beetle’s fascinating life cycle, please read this. For information in Japanese, please look here.

oil beetle playing deadoil beetleoil beetleoil beetle

Coleoptera: Meloidae: Meloe coarctatus (hime tsuchihanmyou)
(I hope this identification is correct)
This is a male (see the pronounced bulge in the antenna)