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Title: Cone humidity is a strong attractant in an obligate cycad pollination system
Studies of pollination biology often focus on visual and olfactory aspects of attraction, with few studies ad- dressing behavioral responses and morphological adaptation to primary metabolic attributes. As part of an in-depth study of obligate nursery pollination of cycads, we find that Rhopalotria furfuracea weevils show a strong physiological response and behavioral orientation to the cone humidity of the host plant Zamia furfur- acea in an equally sensitive manner to their responses to Z. furfuracea-produced cone volatiles. Our results demonstrate that weevils can perceive fine-scale differences in relative humidity (RH) and that individuals exhibit a strong behavioral preference for higher RH in binary choice assays. Host plant Z. furfuracea pro- duces a localized cloud of higher than ambient humidity around both pollen and ovulate cones, and R. furfuracea weevils preferentially land at the zone of maximum humidity on ovulate cones, i.e., the cracks between rows of megasporophylls that provide access to the ovules. Moreover, R. furfuracea weevils exhibit striking antennal morphological traits associated with RH perception, suggesting the importance of humidity sensing in the evolution of this insect lineage. Results from this study suggest that humidity functions in a signal-like fashion in this highly specialized pollination system and help to characterize a key pollination- mediating trait in an ancient plant lineage.  more » « less
Award ID(s):
1906333
PAR ID:
10472736
Author(s) / Creator(s):
; ; ; ; ; ;
Publisher / Repository:
CellPress
Date Published:
Journal Name:
Current Biology
Volume:
33
Issue:
9
ISSN:
0960-9822
Page Range / eLocation ID:
1654 to 1664.e4
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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