Nocturnal hunting of a brightly coloured sit-and-wait predator

Abstract

Many studies have shown that colour signals are important in spidereinsect interactions. The bright body coloration of certain orb-weaving spiders seems to serve as a visual lure to diurnal prey. However, no studies have examined whether this coloration affects spiders’ nocturnal hunting. Some nocturnal lepidopteran pollinators use colour vision to locate their food resources, so orb-weaving spiders’ bright coloration may also be attractive to visually oriented nocturnal insects. To assess the role of body coloration of the orchid spider, Leucauge magnifica, in luring nocturnal prey, we investigated whether: (1) these spiders actively hunt during the night; (2) nocturnal prey comprise a significant proportion of total prey intake; and (3) altering body colour signals significantly affect the nocturnal prey capture rate. Round-the-clock monitoring of L. magnifica activity patterns showed that they hunt more actively at night. Owing to the presence of relatively large moths in their diet at night, L. magnifica consumed higher prey biomass during nocturnal hunting, although this was not statistically significant owing to large variability. Painting over the spiders’ yellow ventrum stripes significantly reduced their moth capture rate. These results show that certain orb-weaving spiders with bright body coloration attract nocturnal prey, and they obtain larger prey from nocturnal hunting.