Night and day: Contributions of diurnal and nocturnal visitors to pollen dispersal, paternity diversity, and fruit set in an early‐blooming shrub, Daphne jezoensis

Abstract

PremiseUnder uncertain pollinator visit conditions, plants often exhibit long flowering periods and generalized pollination systems. Flowering of the gynodioecious shrub Daphne jezoensis occurs early in spring in cool temperate forests. Pollination by nocturnal moths is expected due to tubular‐shaped flowers with sweet fragrance and nectar. However, the effectiveness of nocturnal moths under cool conditions remains unknown. In this study, we evaluated the relative importance of diurnal and nocturnal visitors as pollinators in early spring.MethodsFlowering duration, flower visitors, and floral scents were investigated in a natural population. We experimentally exposed flowers to visitors only during daytime or nighttime by bagging treatments and evaluated the contributions of diurnal and nocturnal insects to fruit set, pollen dispersal distance, and paternity diversity using 16 microsatellite markers.Key resultsFemale flowers lasted approximately 3 weeks, which was approximately 8 days longer than that of hermaphrodites. Various insects, including Coleoptera, Diptera, Hymenoptera, and Lepidoptera, visited the flowers during both daytime and nighttime. Flowers emitted volatiles, such as lilac aldehyde isomers and β‐ocimene, which are known to attract moths. Fruit‐set in the night‐open treatment was similar to or higher than in the day‐open treatment. However, the pollen dispersal distance in the night‐open treatment was shorter than in the day‐open treatment. Paternity diversity was similar in day‐open and night‐open treatments.ConclusionsEarly‐blooming plants ensure pollen receipt and dispersal by having a long flowering period and using both diurnal and nocturnal flower visitors, suggesting the importance of a generalized pollination system under uncertain pollinator visit conditions.This article is protected by copyright. All rights reserved.

Lonesome plants: How isolation affects seed set of a threatened dioecious shrub

“…A plausible explanation is that the foraging range of V. chilensis pollinators, which are likely moths based on findings from research on its sister species, V. quercifolia (Cerino et al., 2015 ), may extend beyond the scale of within‐population female aggregation (up to 23 m in PLV, see Figure 2 ). Moths from the Noctuidae (Cornet et al., 2022 ; Shibata & Kudo, 2023 ) and Sphyngidae (Lewis et al., 2023 ; Skogen et al., 2019 ) families exhibit foraging ranges from several meters to several kilometers. Thus, if V. chilensis is moth‐pollinated, these insects could effectively connect all plants within a population through pollen transfer, maintaining genetic diversity.…”

Pollination across the diel cycle: a global meta-analysis

“…For example, plants conforming to the moth-pollination syndrome (i.e., white, fragrant, tubular flowers) are, in fact, pollinated by a diversity of nocturnal and diurnal insects (Slauson 2000, Funamoto andOhashi 2017). Moreover, having temporally generalized pollination can increase visitation across a diel cycle and provide resilience against local pollinator extinctions (Walton et al 2020, Shibata andKudo 2023). Nonetheless, it remains widely assumed that specific floral traits are associated with nocturnal or diurnal pollination (Valdivia and Niemeyer 2006).…”