Flower Chafer Grub Crawling on Its Back ハナムグリ幼虫の背面歩行

A fat grub of flower chafer (Cetoniinae sp., family Scarabaeidae) was wandering over the sidewalk. Incredibly, the larva always crawled on its back with the help of hairy ridges. The thoracic legs were short and useless for walking. One-yen coin was placed as a scale reference (20 mm in diameter). After the filming, the reckless jaywalker was relocated to the safe ground. Late-September 2010 in Japan.
http://picasaweb.google.com/lh/photo/JpVm_8vTCs5jeTZYOX8KWw?feat=directlink

農地横の舗装歩道で丸まると太った幼虫が徘徊していました。よく見ると奇妙な移動法で、背面を下にした仰向け姿勢のまま蠕動しています。背中に生えた剛毛と地面の摩擦力で­前進します。3対（6脚）の立派な胸脚があるのに決して歩行には使いません。これはハナムグリの仲間の幼虫に特有な運動だそうです。『ファーブル昆虫記』で読んで知ってい­ましたが、実物をじっくり見るのは初めてかも。体の向きを変えてやり、うつ伏せにすると腹面の胸脚を使って歩くようになるでしょうか？　しばらく擬死した後、寝返りを打って仰向けになり、頑固に背面歩行を再開します。しかし腹面にも剛毛が生えているので、単純な毛の有無では説明できません。そもそも腹面を­下にすると重心が不安定になるようで、すぐに転がってしまいます。面白がって実験を繰り返すと、疲れてしまったようです。撮影後は車に轢かれないよう、道端の草叢に放って­やりました。次回は飼育に挑戦してみようかな。発達した大顎も印象的でした。

Category:

Pets & Animals

Tags:

• flower
• chafer
• beetle
• larva
• grub
• walk
• locomotion
• crawl
• back
• wriggle
• grubworm
• ハナムグリ
• コガネムシ科
• 幼虫
• 甲虫
• 背面
• 歩行
• 徘徊

[SteveMcHope]

hi sigma,

can u tell me the name of the chapter or the number of the book of fabre where he is describing this?

cu steve

[sigma1920]

@SteveMcHope

i have only two versions of japanese translation.

but the chapters were rearranged by the modern translator and they r different from the original.

hence my info must be useless for u.

(can u read japanese?)

there is even an accompanying cartoon on the page to show young readers the behaviour.

fabre wrote about some grub of flower chafer in the chapter of scoliid wasps as their prey.

he studied the life cycle of the beetle itself somewhere in the later chapter.

[sigma1920]

@SteveMcHope

u can read similar description in the entry of “hanamuguri” (flower chafer) in the japanese wikipedia.

unfortunately, i cannot find any basic info about the larval locomotion in other languages of wikipedia.

that clearly shows how deeply we japanese r influenced by fabre.

[SteveMcHope]

Hi sigma,

this is very interesting. I have never heard or read about this behavior.

But this larvae seems to do it really perfect - does not look like an accident.

All the best

Steve

[sigma1920]

@SteveMcHope

hello.

ive read about this weird behaviour in the "souvenirs entomologuques" by J. H. Fabre.

he is great!

in fact, i could tell it was a larva of flower chafer because of the unique locomotion.

this footage is just a tribute to his description.

[selfishcrow]

really fascinating

(joke time) He is Break Dancing !!