Visual and olfactory responses of foraging Papilio memnon
Author of the article:LIU Jie LI Ming-Tao CHEN Shun-An SHI Lei CHEN Xiao-Ming
Author's Workplace:Key Laboratory of Cultivating and Utilization of Resources Insects of State Forestry Administration, Research Institute of Resources Insects, Chinese Academy of Forestry, Kunming 650224, China; Nanjing Forestry University, Nanjing 210037, China
Key Words:Papilio memnon; visual; olfactory; colors; floral volatiles; electroantennogram; behavioral responses
Abstract:
[Objectives] To investigate the use of visual and olfactory information during
foraging by the butterfly Papilio memnon. [Methods] The cues used by P. memnon to
locate food plants were investigated using different colored artificial flowers
and artificial flowers sprayed with honey water. In addition, the antennal
responses of P. memnon to floral volatiles were measured with an
Electroantennogram (EAG), and significant responses to specific volatiles were
later verified in behavioral trials. [Results] When given a choice between 7 colours of
odorless, artificial flowers butterflies displayed an obvious preference for blue
(440-475 nm), purple (380-420 nm) and red (615-630 nm), flowers. The
application of 10% honey solution to these flowers resulted in a 1.85-fold
increase in the mating frequency of female and male butterflies. Butterflies
did not respond to a single odor (honey, benzyl, alcohol or benzaldehyde).
However, the application of honey to artificial blue flowers was followed by a
27.4 fold increase in the chasing frequency of adults, and the application of
benzyl alcohol and benzaldehyde increased the number of visits to these flowers
by 52.59 and 75.80 fold, respectively. Compared to color, color plus honey
solution increased the number of visits by 1.41 times, whereas the use of
benzyl alcohol and benzaldehyde increased the visitation rate by 2.67 and 2.16
times, respectively. Females were more responsive than males to both color and
volatile compounds (P<0.05). [Conclusion] Color is the main
factor influencing the foraging activity of P. memnon. Single odors have
a limited effect, olfaction playing a secondary, but complementary, role to
vision. Females have better color and odor recognition than males, which may be
related to their reproductive role.