Re: [aroid-l] From Peru

From: "Julius Boos" ju-bo at msn.com> on 2002.08.22 at 23:41:00(9270) Dear Jorge and Dr. Barton, I am NOT an 'expert' in this field, but have read and observed quite a bit on pollination of Araceae, and will try to help w/ a few commnets. Pollination of the genus Philodendron, Monstera (and Dieffenbachia) are reported to be pollinated by scarab beetles mainly of the genus Cyclocephalla and other closely related genera. Many other insects may be discovered associated with and attracted to the scent of the open flower, but the actual 'job' of pollination is reported to be by these scarab beetles. I believe the same genus of scrab also pollinates Xanthosoma and Caladium, as I collected many beetles of this genus in blooms of Xanthosoma sps. while I worked in Ecuador, both on the E. and W. side of the Andes. During the Aroid Symposium held at MOBOT a few years ago, Sue Thompson and another Gentleman (for the life of me I can not recall his name, sorry!) gave most interesting talks on this subject, and both cautioned on assumptions made when insects just happened to be found in association with a bloom, many slides were shown illustrating this, and the pollen seems to have evolved to suit a very specific insect. Other insects just take advantage of an available food source, eating the 'bait' provided by some genera, in the case of Xanthosoma some of the sterile flowers, others (non-pollinators) eating and destroying the female flowers, thus actually perventing seed development. We were shown photos of the damage some beetles do to the blooms of aroids by burrowing through the spathe tube limb to reach this rich food 'reward', but they do nothing to assist the plant in pollination. Lots of close observation will be needed, as in some cases a VERY specific beetle/insect may be required, for example on Trinidad MANY Caladiums (mainly C. bicolor) are found blooming in the wild, yet not once have we discovered a developing infructesence. It is suspected that this plant may have been introduced to Trinidad by pre-Colombian man and the specific pollenator is not present. It could be that lots more observation is needed and a plant in fruit may yet be located. On the other hand some other aroids do not seem to need a specific pollinator, as my plants of Urospatha, Dracontium and Dracontioides were pollinated by insects that occur here in W.P.B., Florida. In some cases no pollination is required for the plant to produce viable seed, Anthurium gracille and other closely related species do this with no pollination. I hope tha above may serve as a 'beginners guide', comments and discussion are most welcome!!. Jorge, if you have more than one blooming plant of Xanthosoma, hand-pollination is easy and seed can be produced by this method. Julius +More >>Dear Dr. Barton : Thanks for your interest in my investigation, I must comment you that I'm just beginning my work, in this time I'm gathering all the data to start my investigation. What I know about this issue is something very general now, I have the idea that Araceae are pollinated by euglossine bees, trigonid bees, beetles (Curculionidae, Nitudilidae, Scarabaeidae, Scydmaenidae, Staphylinidae) and flies (Drosophilidae). I brought from my last trip specimens of Anthurium gracile, a species that flowered and fructified at my home ... I live in the other side of the Cordillera de los Andes from where it natural habitat is. Besides I have another species of Xanthosoma, (not determined yet) whose first flowering didn't fructify... I hope this time it does (it will blossom). I think there could be another insects to pollinize it, at least the species that are pollinated by flies or bees... some cosmopolite species and maybe they could be replaced by other species, while the pollinized by beetles or other insects not well distributed is more difficult. I wait your comments in this matter. Truly yours. Jorge Lingan<< _________________________________________________________________ MSN Fotos: la forma m?s f?cil de compartir e imprimir fotos. http://photos.msn.es/support/worldwide.aspx

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