Plants in the Asclepiadaceae family have rather complex pollination requirements when compared to plants that simply dust a pollinator with pollen. In this group of plants a pollinator's foot enters a channel and if it fits properly, it can pull out the pollen mass (pollinia) and, if all goes well this can be transferred to anther flower to achieve pollination. Imagine a lock and key with the key being the properly sized insect foot.
Plants in this group have different floral scents so they attract different pollinators. Putrid rotting meat scents that are common in the Stapeliads will attract flys, other scents might attract beetles. Hoyas are commonly fragrant at night so moths are their major pollinators. If you search "Hoya Moth" in the Hoya forum you will get some great photos of blooms being swarmed by moths.

Here is an article on hand pollination of Stapeliads. Hoya pollination is essentially the same, it's very difficult to achieve.

Mike

Here is a link that might be useful: Pollination systems in the Asclepiadaceae

I forgot the link to the page explaining how to hand pollinate.

Mike

Here is a link that might be useful: Stapeliad Pollination

I have a question about hand pollinating, Mike. I've tried to hand pollinate several times in the past, but every time I have successfully loosened a pollinia, and is ready to insert it in another flower, I don't know exactly where to put it!

Do you have a picture (maybe with arrows on it) to point out exactly where it's supposed to go, and which way it's supposed to go in there? I can't seem to get it to stick anywhere. I just end up trying to push/force it in wherever I can get it in. LOL And it never works!

I to have tried and failed many times.
The basic idea is to remove the pollinia by using a stiff bristle (cat's whisker has been recommended). By dragging the tool down through the channel that separates each of the lobes that make up the central corona, the star shaped part in the centre of a Hoya's flower. To pollinate you simply do the same on another flower and hope that the pollinia catches. I believe that when you are trying to get the pollinia you should work from the centre of the flower outwards but to deposit the pollinia you should work from the outer edge inwards. If you were to dismantle a Hoya's flower into it's parts you would see that directly in the centre of the corona lies the pollen tube that allows the pollen to travel down the style and into the ovule where fertilization occurs. These reproductive organs are obscured by the coronal scales that make up the star shaped corona. Maybe sacrifice a flower to dissect so you can see how the flower is structured. Breaking away the corona and then breaking it into its pieces will give you a better understanding of the flower structure. After removing the corona you will see the receptive area where you are trying to deposit the pollinia.

Hopefully that helps but if not maybe I can come up with a diagram.

Mike

I already knew how to get the pollinia OUT, it's the IN part that's giving me the headache. LOL :) And I've dissected too many flowers to count, and I STILL can't seem to figure out the exact location to put the pollinia. :-P But if it's like you say (it's the same channel that is used to get the pollinia out, only the reversed direction) then I've been doing it right. Well, not quite right since I've had no success, but I guess it's just a trial and error sort of thing. Just have to keep practising. Thank you for your answer, Mike. I really appreciate it!

I was trying and trying to imagine people plucking whiskers out of the faces of their pissed off cats, and then I finally realized that they probably used scissors.

Duh...

Here kitty kitty.............ha ha ha

I actually found one of my Chihuahua's whiskers on the floor so I kept it to use. Otherwise I was trying to use very thin wire but it was not working very well.

Klea the hard part with Hoyas is getting the pollinia to be accepted. I really don't fully understand. Other plants such as orchids also have pollinia. In orchids there is a sticky area that accepts the pollinia so hand pollination is not difficult. With Hoyas the pollen mass seems so large for the receptive area that I wonder if single grains of pollen simply rub off and achieve pollination vs the whole pollen mass being required.

Mike

Yes thank you Mike for some very informative material on pollinating. I guess in the next few weeks I'll find out if the ants had the right " key" to make it successful!!