Dear Peter,

current knowledge on pollination of H. tridactylites, which seems to be very poor, is summarized by Claessens & Kleynen (Fl.Eur.Orch.: 199-203. 2011). The presence of scent and removed pollinaria indicate strongly insect-pollination. According this monograph only Paulus (Ber. Arbeitskr. Heim. Orch.16(1): 21. 1999) observed once a pollinator, probably Mamestra brassicae.

Best wishes, Richard

Dear Peter,

Habenaria tridactylites is indeed pollinated by butterflies, not by bees. The main pollinators are Noctuidae, Geometridae, Crambidae, Pyralidae and Tortricidae (summarized in Claessens & Kleynen 2016). I cannot confirm pollination by Danaus plexippus. I expect to publish the results in 2018.

Best wishes,

Jean

Richard, Luis Miguel and Jean, thanks for your response!

According to own observations in East-Sulawesi, Habenaria can obviously be (selectively) pollinated by several species of Danainae but not by other butterflies.

Best wishes, Peter

Habenaria can also be autopollinate ? It seems -yes.

Dear Marpha,

obviously some Habenaria are self-compatible but are dependent on a pollinator others are able to auto-pollinate. Here are 2 references:

Pedron M, Buzatto CR, Singer RB, Batista JAN, Moser A (2012) Pollination biology of four sympatric species of Habenaria (Orchidaceae: Orchidinae) from southern Brazil. Botanical Journal of the Linnean Society 170, 141–156.

Jacquemyn H, Micheneau C, Roberts DL, Pailler T (2005) Elevational gradients of species diversity, breeding system and floral traits of orchid species on Réunion Island. Journal of Biogeography 32, 1751–1761.

Best wishes,

Peter

Dear Peter,

thank for reference n°1 about Habenaria,

but i not apreciat the interprétation of C.Micheneau from his observation

Best regard,

Marpha

Habernaria is the self compatible, but it may be.....

Generaly, butterflies visite the flowers to collect nectar. In kase of the plant is a host of this insect, it may be an important pollinator for this plant.

Orchids do not generally provide nectar ... several species indeed do not. Butterflies of the family Danainae are attracted by plants such as Boraginaceae which produce pyrrolizidine alkaloids. The latters are used by the butterflies for the biosynthesis of own hormones for example. Orchids are also capable to synthesize these types of alkaloids. Furthermore it is known that Danaus plexippus visits orchids and may transport pollinia.

[see: > Boyden, T.C. 1980. Floral mimicry by Epidendrum ibaguense (Orchidaceae) in Panama. Evolution 34:135-136.

> Fuhro et al. 2010. Are there evidences of a complex mimicry system among Asclepias curassavica (Apocynaceae), Epidendrum fulgens (Orchidaceae), and Lantana camara (Verbenaceae) in Southern Brazil? Revista Brasil. Bot. 33, 589-598.]

So my question is whether D. plexippus can be selectively attracted to Habenaria tridactylites by specific volatile compounds.

Peter

When initiating this discussion I stated that "I have good hints that Danainae are pollinators of Habenaria species in South-East Asia."

I uploaded an image in my project on "Orchid pollination by Danainae" to corroborate this predication.

Peter