Hoya, with around 300 species, is the largest genus in Asclepiadoideae tribe Marsdenieae in the family Apocynaceae. Hoya species produce white flowers, strong nocturnal fragrance and abundant nectar. The pollination of two Hoya species has been studied previously, but little is known about the specific nature and interactions between flower morphology, pollinators, and their environment.
source https://phys.org/news/2021-01-effective-pollinator-hoya-pottsii-revealed.html