Biology subjects

Lunau, K.

Publications and source records attributed to Lunau, K..

3 recordsLinked to original sources

bioRxiv2025

Nuances of floral mimicry in Queen of Sheba orchids

O_LIBackground and Aims Floral deception can range from finely tuned mimicry of specific rewarding plants (Batesian mimicry) to a general resemblance of the rewarding community (generalised food deception). We focused on two species in the deceptive Thelymitra variegata complex (Queen of Sheba orchids) to examine whether pollination is consistent with generalised food deception or with specific mimicry of co-flowering buzz-pollinated tinsel lilies (Calectasia spp.). C_LIO_LIMethods We assessed i) overlap in flower colour and scent between orchids, tinsel lilies, and other flowers in the rewarding community, ii) pollinator sharing between orchids, tinsel lilies and other species, and ii) quantified orchid reproductive success in relation to abundance of tinsel lilies and other rewarding species. C_LIO_LIKey Results We found that T. speciosa matches flower colour and scent of its co-flowering tinsel lily, C. gracilis, while T. porphyrosticta partly overlaps with co-flowering C. demarzii in both traits. The orchids and tinsel lilies shared flower visitors, and the only visitor observed to transfer orchid pollen was Anthoglossa plumata bee (Colletidae) that displayed a behaviour associated with buzz pollination. This species was also observed to buzz-pollinate tinsel lilies. In T. speciosa, fruit production increased with abundance of both tinsel lilies and other rewarding species with similar flower colour, suggesting a combination of mimicry and magnet effects. However, relationships were driven by a single population. There was no association between rewarding community and reproductive success in T. porphyrosticta. C_LIO_LIConclusions The results are partly consistent with mimicry towards the co-flowering tinsel lily for both orchids. Specific mimicry is strongly supported by a close resemblance involving multiple floral traits, and by bee behaviour associated with the buzz-pollinated model. However, this contrasts with the lack of consistent effects of tinsel lily abundance on orchid reproductive success. The findings further suggest that shared floral scent may reinforce visual similarity and highlight that scent may be important in food mimicry systems. More generally, the T. variegata complex offers an interesting system for studying nuances between specific mimicry and generalised deception. C_LI

ecology↗

bioRxiv2022

Mimicking orchids lure bees from afar with exaggerated ultraviolet signals

O_LIFlowers have many sensory traits to appeal to pollinators, including ultraviolet (UV) absorbing markings, which are well known for attracting bees at close proximity (e.g. < 1 m). While striking UV signals have been thought to attract pollinators also at greater distances of meters, how the signals impact the plant pollination success over distance remains unknown. Here we report the case of the Australian orchid Diuris brumalis, a non-rewarding species, pollinated by bees via mimicry of rewarding pea plant Daviesia decurrens. When distant from the pea plant, Diuris brumalis was hypothesized to enhance pollinator attraction by exaggerately mimicking the floral ultraviolet (UV) reflecting patterns of its model. C_LIO_LIBy experimentally modulating floral UV reflectance with a UV screening solution, we quantified the orchid pollination success at variable distance from the model plants. C_LIO_LIWe demonstrate that the deceptive orchid Diuris brumalis attracts bee pollinators by emphasizing the visual stimuli, which mimic the floral UV signalling of the rewarding model D. decurrens. Moreover, the exaggerated UV reflectance of D. brumalis flowers impacted pollinators visitation at an optimal distance from D. decurrens, and the effect decreased when orchids were too close or too far away from the model. C_LIO_LIOur findings show that salient UV flower signalling plays a functional role in visual floral mimicry, likely exploiting perceptual gaps in bee neural coding, and mediates the plant pollination success at much greater spatial scales than previously expected. C_LI

ecology↗

bioRxiv2019

High innate preference for black substrate in the chive gnat, Bradysia odoriphaga (Diptera: Sciaridae)

The chive gnat, Bradysia odoriphaga, is a notorious pest of Allium species in China. Colour trapping is an established method for monitoring and controlling of Bradysia species. In order to clarify the effect of colour preference of B. odoriphaga for the egg-laying substrate, multiple-choice tests were employed to assess the spontaneous response of the chive gnat to different colour hues and brightness levels under different intensities of white illumination and two spectrally different illuminations. Given the choice among four colours differing in hue under different intensities of white illumination and two spectrally different illuminations, chive gnat adults visited preferably the black substrate, a lesser extent to brown and green substrates, and the least extent to orange substrate irrespective of illumination. Given the choice among four levels of brightness under the same illumination conditions as those in the previous experiment (different intensities of white illumination and two spectrally different illuminations), chive gnats preferred black substrate over dark grey, and these over light grey and white substrates. Meanwhile, both virgin and copulated adults significantly preferred black over other colour hues and brightness. Based on our results, we conclude that the chive gnat adults significantly prefer black substrates irrespective of colour hues and brightness. This behaviour does not alter due to ambient light condition changes. No difference observed between choices of female and male adults. Our results provide new insight for understanding the colour choice behaviour in chive gnat and pave a way to improve monitoring and control of chive gnats and management.\n\nSummary statementChive gnat (Bradysia odoriphaga) innately prefer to move to black substrate irrespective of colour hues and brightness. This behaviour maintained the ambient lights change.

animal behavior and cognition↗