Cyclocephala castanea is a species of small beetle in the family Scarabaeidae which is native to the Amazon basin in South America.

Visiting the flower for food, the beetles are trapped inside and emerge laden with pollen the following evening.

The beetles are attracted to the flowers which have a high temperature, up to 10 °C (18 °F) warmer than their surroundings, and which contain starch-rich appendages called paracarpels.

The beetles also benefit; they have a period to feast on the specialised food tissues provided for them by the plant, and plenty of time in close proximity with one another for mating.

[5] Additionally, there have been reports of Cyclocephala castanea beetles visiting Nymphaea glandulifera flowers in Surinam.