More on osmeteria

[Kenelm Philip]

	In Scoble (The Lepidoptera: Form, Function and Diversity) there is
a reference to the following paper:

Eisner, T. & Meinwald, Y.C. 1965. Defensive secretions of a caterpillar
(_Papilio_). Science 150:1733-1735.

Scoble states that the defense is against predators. He admits that much
of the evidence is circumstantial, _but_ he then refers to the following
paper:

Damman, H. 1986. The osmaterial glands of the swallowtail butterfly
_Eurytides penella_ (Hbn.) (Lep.). Zoologischer Anzeiger 176: 449-464.

Experiments were made, and the osmeteria were shown to provide an effective
defense against predators in spring, but not in summer. Attacks by ants
and small spiders were deterred, but not by large spiders, vespid wasps,
and a parasitoid wasp specializing in this butterfly. Ants and small spiders
are important predators in the spring, less so in summer.

Spelling note: Damman, and others, spell the word 'osmaterium'. Scoble
adds '[sic]' in his reference to Damman's paper--so he at least thinks
the 'a' is incorrect.

	There is also a short section about _Papilio_ osmeteria by L.P.
Brower in Vane-Wright and Ackery's 'The Biology of Butterflies'. Brower
thinks a lot more work needs to be done...

							Ken Philip
fnkwp at uaf.edu