Flower visits of cockroaches (Insecta: Blattodea) in the Iberian Peninsula: Are they neglected pollinators?

Abstract

Although several insect orders have been deeply studied in plant–animal interactions (e.g. pollination) cockroaches have traditionally been ignored in taxonomic and ecological studies. However, they could be playing a role in the reproduction of several plants. To date, 8 plant species use cockroaches as a pollination agent. In our study, we have reviewed 2865 records from citizen science platforms and our own data from the Iberian Peninsula to find flower visits made by cockroaches. We have detected 51 interaction records involving at least 8 different cockroach species and 35 plant species. Furthermore, nearly half of the detected cockroaches carried pollen on various parts of their bodies. These insects were found to mainly visit white, yellow and pink flowers from Apiaceae, Asteraceae and Cistaceae plant families (among others) mainly in late spring and early summer. However, for the confirmation of effective pollination, new studies must be carried out. Additionally, although the existence of pollination syndrome is far from being understood, we provide new insights that could help shed some light on this unknown relationship. Here we provide the first approximation of cockroach floral perception and we have detected that white flowers show the best fit and higher conspicousness to cockroach colour vision, as suggested for other neglected pollinator insects.