(B) A mantis ( Hierodula patellifera) eating a hawkmoth ( Theretra japonica) on Clerodendrum trichotomum. (A) A mantis ( Tenodera sinensis) eating a settling moth ( Sarcopolia illoba) on Eupatorium lindleyanum. Nocturnal ambush predators preying on flower-visiting moths. However, few studies have quantified the abundance of nocturnal predators on flowers and their predation pressures on nocturnal pollinators in the field.

Nocturnal moths on flowers are reportedly eaten by spiders (Morse 1983), mantises (Delf and Harris 1964), and bats (Martins and Johnson 2013). This suggests that ambush predators such as praying mantises prey on nocturnal pollinators, as they do on diurnal pollinators. On 19 September 2018, we found a praying mantis, Tenodera sinensis (Mantodea: Mantidae), eating a moth, Sarcopolia illoba (Lepidoptera: Noctuidae), on flowers of Eupatorium lindleyanum (Asteraceae) at night in Hyogo, Japan (Fig. Although nocturnal insects such as moths are important pollinators of many flowering plants (Hahn and Brühl 2016), the impact of ambush predators on nocturnal pollinators remains unclear. Thus, ambush predators can diminish the reproductive success of flowering plants (Gonçalves-Souza et al. Ambush predators such as spiders affect the flower-visiting behavior of diurnal pollinators such as bees (Dukas 2001, Dukas and Morse 2003), potentially causing diurnal pollinators to avoid flowers where ambush predators wait (Dukas 2001).

Nocturnal spiders