#osmeterium

[onenicebugperday]

@earthandsunandmoon submitted: I will never tire of seeing a swallowtail caterpillar's angry eyebrows!

Lol...agreed, it's very cute every time. Even though it's meant to repel predators, I guess they didn't account for humans.

[briery]

Spicebush larva with osmeterium displayed When these caterpillars are confronted an orange forked gland flicks in and out like a tongue and secretes nasty smelling material. By John Flannery on Flickr. (Hi-Res).

[reanimateobjects]

[sinobug]

Beware the Serpent A penultimate instar Paris Peacock Swallowtail Butterfly Caterpillar (Papilio paris, Papilionidae) deploys its defensive osmeterium. The osmeterium is an eversible glandular organ positioned at the juncture of the head and thorax of Papilionidae immatures. When eversed in response to a threat, it produces a chemical odour shown to repel arthropod predators (ants, spiders, mantids). It seems logical to assume that, in conjunction with the serpent-like eyespots characteristic of final instars, the colouration and forked structure of the osmeterium rounds off the snake mimicry aimed at detering vertebrate threats. Oddly enough, of the many many encounters I have had with Papilionid caterpillars, this has been the only time I have seen an osmeterium in use, albeit fleetingly, and this was the only capture. Personally (and proudly), I feel this may be partly because I don't make a point of provoking or disturbing my subjects. by Sinobug (itchydogimages) on Flickr. Pu’er, Yunnan, China See more Chinese caterpillars on my Flickr site HERE...

[reanimateobjects]

[reanimateobjects]

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[noneun]

Questo cicciottino è un bruco di macaone (Papilio machaon), una delle farfalle più belle che si possano trovare in Italia.

E quello che sembra un grazioso fiocco arancione sulla testolina è in realtà un osmeterium, ovvero un organo che viene estroflesso quando il bruco percepisce del pericolo e che emette un odore sgradevole.

La forma biforcuta e il colore vivace può essere utile a spaventare uccelli, piccoli rettili e ragni, mentre le sostanze chimiche volatili che esso libera respingono o uccidono formiche e mantidi.

Il macaone reagisce così anche solamente quando viene molestato, infatti per provocare questa reazione è sufficiente accarezzare il bruco sulla schiena.

E niente... voglio anch'io un osmeterium.