Surprisingly, Monstera obliqua a species pollinated by small nitidulid scarabs
(Chouteau et al. 2007), appears within the bee-pollinated group. We proposed
several explanations. First, M. obliqua, belonging to the Monsteroideae subfamily,
may be phylogenetically constrained against any drastic floral changes from beepollination
characteristics which are present in other genera of this subfamily.
Second, the pollination of M. obliqua by nitidulid scarabs may be recent from
an evolutionary point of view and the selective pressure of the scarabs on the
floral trait characteristics may still be ongoing. Third, pollination by nitidulid
beetles may not require different floral traits, and those associated with beepollination
may also be adapted to nitidulid beetle pollination leading to a
reduced selective pressure on floral traits by beetles. Fourth, M. obliqua may
be pollinated by bees and the conclusions of Chouteau et al. (2007) could be
erroneous because nitidulid scarabs may not be efficient pollinators. Further
studies of pollination in the genus Monstera are needed to explain the pattern
resulting from the discriminant analysis.