There are many reasons they don't. Some genera are more prone to it than others, mature plants seem to do so more than youngsters, where they are in their growth ebbs and floes, and - yes - how healthy they are, can all play roles.


Ray Barkalow
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Ray thank you. Now I feel somewhat relieved

I just noticed a ton of it on a Poinsettia I'm letting go dormant. The stuff is everywhere!

James: At this point we should probably "agree to disagree". However, I'd like to respond to your last post and I'll leave the field to you. (If you would like to continue through PM's, that would be OK. We have seriously hijacked this thread.)

I have a couple of points. Yes, "happy juice" is produced by osmotic pressure. As a result of my former occupation, though, I'm as interested in the "why" as the "how." Orchids are notorious metabolic sluggards. Why is it that some of them are "willing" (again, an anthropomorphism) to waste copious amounts of sugar in happy juice when logically it would be so precious to them? And why is so much of it released at the flowers? As far as I know, orchids don't even use nectar in their flowers to attract pollinators. As for relieving osmotic pressure, most of the plants in my garden reduce osmotic pressure through special pores on the leaves. And that liquid contains little or no sugar. Any extra sugar is converted to complex sugars and stored or used to build tissue (i,e., cell walls) It seems to me that the "willingness" of orchids to lose so much of this precious resource is an evolutionary response.

Which leads me to my second point. Your response has a contradiction. You said: ..."ants don't guard their sources of nectar..." and, then, in the next sentence you say: "They do, however, protect their herd of aphids..." To an ant, what is an aphid other than a source of nectar. So you're saying, in effect, that ants do protect their nectar sources. Is there any difference between what ants do when they vigorously defend their sources of "happy juice" and when they vigorously defend their aphid herd? If there is a difference, it's not obvious to me.

Finally, this relationship between ants, happy juice and orchids is, in my opinion, a relatively simple relationship. Ants and orchids have evolved an array of relationships that are even more interesting and complicated. Examples would include the pollination strategies of the slipper orchids and the relationship between ants and Coryanthes.

wuness

The question you ask do all orchids produce Honey dew; the answer is no
It's normal for orchids such as Dendrobiums, Oncidiums and Cattleyas to produce honey/sap on the flower stem.
All sorts of fungal and bacterial diseases can pass their way from the honeydew to the hole it came from into the plant. One example that can happen is black mold that coats the plant and severely slows photosynthesis.
I would not worry about it at all.
I have found over the years that humidity seems to play a factor with some species, but that is still ongoing research. Same as why do they do this and how or if it attracts pollinators by doing so.

Most orchids are capable of oozing sap from their tissues. Some of mine do most of the time where there is new growth or an inflorescence. Some don't. Some do at some time and don't at others. Depends on many factors. It's not something they "do", but something that "happens" depending on the circumstances.

I want to correct a serious mistake I made in my last post. There are many orchids that do use floral nectaries to attract pollinators. Many orchids are pollinated by hummingbirds, moths and other animals.

Tons of information flowing in .Thank you guys

If you would like to read more about this interesting relationship, google "myrmecophily" (=ant-loving) and go to the Wikipedia site. Read especially the section "Ant-plant interactions."

wuness

I have read the article and a few others. There are ant species around the world who live a symbiotic lifestyle with different plants. But most ants wouldn't know a pecan tree from a pine tree. They do however know what and where food can be obtained. Carpenter ants in the mountain regions of the world prefer soft woods compared to hardwoods. Argentine ants here and in SA herd aphids and mealie bugs and protect them from other insects. Bull Dog ants eat anything they can get. As do the so called army ants. There are three species of ants which live in the stems of orchids. Most ants eat the sap of vegetation whenever they can find it. Most carry it back to their nests and either directly feed their larvae or regurgitate it to nurture their gardens of fungi and molds. Ants such as the argentine ant transport their cattle from plant to plant not caring if it is orchid or sunflower. Look up ScienceDaily: News, Videos & Articles in Science, Health, Technology & Environment and search "ants". Interesting research articles.