Does cycas emits insect attracting 'fragrance'?

[han]

Hi, just wondering if cycas in particular emits some kind of 'fragrance' when it is or is about to flush? I notice this in all of my cycas where it will attract the nasty small butterfly to lay eggs (Asian Blue?).

But for my macrozamia, zamia, dioon, encerphalartos, no insect will bother them at all.

[Kris]

Hi, just wondering if cycas in particular emits some kind of 'fragrance' when it is or is about to flush? I notice this in all of my cycas where it will attract the nasty small butterfly to lay eggs (Asian Blue?).

But for my macrozamia, zamia, dioon, encerphalartos, no insect will bother them at all.

Yes,even i have noticed the same thing in our cycads here,but i think the reason is that the moths,catapillers all fest on the new flushes,eventually wrecking havoc to the very existance of the cycas.And C.Revoulta is the maxium affected in our experience.And it has nothing to do with smell.but its their food.

Love,

Kris

[virtualpalm]

Han, very little is known about this subject. However, I sent your question and Kris' response to my friend Dr. Irene Terry (author of the "odor-mediated push-pull" cycad pollination hypothesis published in the journal Science back in 2007 [http://www.sciencemag.org/cgi/content/full/sci;318/5847/70]). Her response is below:

"All these observations - which generally are what I have observed - seem consistent with possible scent attraction to new leaf or cone development that might be particular to Cycas species; there are a lot of green leaf odors that might attract."

Interesting indeed!

Jody

[han]

Han, very little is known about this subject. However, I sent your question and Kris' response to my friend Dr. Irene Terry (author of the "odor-mediated push-pull" cycad pollination hypothesis published in the journal Science back in 2007 [http://www.sciencemag.org/cgi/content/full/sci;318/5847/70]). Her response is below:

"All these observations - which generally are what I have observed - seem consistent with possible scent attraction to new leaf or cone development that might be particular to Cycas species; there are a lot of green leaf odors that might attract."

Interesting indeed!

Jody

Hi Jody,

Thanks for the answer from Dr Irene. I believe it is indeed the special scent from cycas, as even before any flush from the cycas, I can see active butterflies activities around the cycas which also signal me to protect the cycas new leaves.

By the way, does anyone have easy tips to protect the flush from damaging by the larva of the butterfly?

[Phil]

I think a lot of us who grow cycads are well aware of the odor of a cycad cone, especially the males. I think the genus Cycas are probably the most potent but many other species have a familiar fragrance as well. Some describe the odor as a "pepper" smell. If you follow a function/morphology logic, one would ask why do these cones emit an odor? It might seem to make more sense to have the male cones emit more of the odor such that insects (if attracted) would cover themselves with pollen and eventually find a female. In my experience, it is the male cones that give off more of the smell. I think I could smell a male Cycas cones from a hundred feet. One learns the odor and spots it again later. And, it's a pretty unmistakable odor. Early in my cycad career I liked the smell described above. As the years go by, I'm less fond of it.

Phil