Visitation of African pineapple lily flowers (Eucomis autumnalis (Mill.) Chitt. and Eucomis comosa Houtt. ex. Wehrh.) by Japanese cockroaches

Abstract

Pineapple lilies Eucomis autumnalis (Mill.) Chitt. and Eucomis comosa Houtt. ex. Wehrh. are endemic herbaceous plants in southern Africa but are planted as ornamental bulbous plants globally. The flowers are known to be primarily pollinated by pompilid wasps in their native range. In a Japanese botanical garden, Blattella nipponica Asahina, 1963 cockroaches visited the inflorescences of the two Eucomis species, fed on the floral nectar, and used the comae (i.e., leaf-like tufts on the top of inflorescences) as physical shelters and transported the pollen, thereby resulting in a fruit set. Ants, flies, and beetles were also observed to visit the flowers but did not touch the anthers or stigmas. These observations suggest that ground-dwelling cockroaches can act as pollinators of Eucomis flowers in an ex-situ setting.