Beetle pollination of Philodendron solimoesense (Araceae) in French Guiana

The pollination of Philodendron solimoesense (subgenus Meconostigma) was st udied in four populations of French Guiana. Flowering is asynchronous withi n each population during July and the flowering cycle is a 2-d process. Num erous insects visit Philodendron inflorescences, but the main pollinator se ems to be Cyclocephala colasi (Scarabaeidae, Dynastinae). The pollination p rocess displays aspects typical of beetle pollination: the production of he at and of a strong odor, the presence of a food reward (stigmatic secretion and sterile male flowers), and the presence of a copula don chamber. Flowe r heat production is important (ca. 11 degrees C above the ambient air) and may help to volatilize the fragrance. Attraction and choice-test experimen ts showed that C. colasi is not likely to depend on chemical information (s uch as pheromone) to localize conspecifics but may rely instead on stimuli produced by the inflorescences in order to meet mating partners.