Floral traits and environmental factors regulate insects visits to
flowering plants at night
Abstract
Flower-visiting insects have co-evolved with flowering-plants. While it
has been shown that floral traits and environmental factors influence
insects visitations during the day, it is yet unclear how these factors
influence insects visitations at night. We sampled a montane meadow
located near Jilin in northeastern China in July and August in 2019, 4
nights each month, and two time periods each night. We sampled 94
flower-visiting insect species in total and documented the floral traits
and ambient factors. First, focusing on the insects functions, we
allocated all insects into three functional groups (pollination,
predation, and feeding). We found that most nocturnal insects exhibited
predation behavior, and they had the highest species turnover rate.
Second, focusing on the environmental factors, we found that ambient
temperature and relative humidity strongly influence the diversity of
flower-visiting insects. Variation partitioning analysis further
suggested that ambient temperature has a stronger effect on the
flowering-visiting insects at early night, while the relative humidity
has a stronger effect on the flowering-visiting insects at late night.
Third, focusing on floral traits, we found that most insects have a
preference for flowers with moderately-sized corolla diameters (20 to 30
mm). Furthermore, display size had a strong linear correlation with
flowering-visiting insect species richness and frequency of presence. In
sum, our findings suggest that ambient temperature, relative humidity,
and floral display size strongly regulate nocturnal flower-visiting
insects.