Abstract Detail

Recent Topics Posters

Doubleday, Laura [1], Adler, Lynn [2].

Hermaphrodite-biased oviposition on a gynodioecious host plant in a novel nursery pollination interaction.

In flowering plants, the evolution of separate sexes (dioecy) from hermaphroditism often progresses through gynodioecy, where individuals are either female or hermaphrodite. Pollinators and herbivores frequently prefer the pollen-bearing sex in dioecious and gynodioecious plant species, making male function both lucrative and dangerous. Nursery pollination, where adult insects pollinate flowers but also lay eggs in them, is an interaction where one species is both pollinator and herbivore. Many Silene plant species have nursery pollination interactions with Hadena sp. moths.  
We assessed moth oviposition preferences and fitness consequences for females and hermaphrodites in a novel interaction between gynodioecious S. vulgaris and H. ectypa in New England. Hadena ectypa recently shifted onto S. vulgaris from its native host plant, hermaphrodite S. stellata, on which it is largely parasitic. The novelty of the S. vulgaris–H. ectypa interaction allows investigation of how nursery pollination arises.  
Oviposition was hermaphrodite-biased, and affected by among- and within-plant traits. Plants with more flowers and flowers with wider calyces were more likely to receive eggs, and larger plants received more eggs. Hermaphrodites had more flowers than females, but plant size and calyx width were not sexually dimorphic. Plant sex also predicted oviposition after accounting for these traits, suggesting that other unmeasured sex-related traits also contributed to the moth’s preference for hermaphrodites. Oviposition usually resulted in no seed production by egg-receiving flowers and early-season oviposition had no effect on subsequent fruit production. Regardless of receiving eggs, females produced more fruits than hermaphrodites, but there was no difference between the sexes in the number of seeds per fruit. 
Our results suggest that H. ectypa is neutral for females and hermaphrodites. Combined with work in other Silene–Hadena systems, our results suggest that nursery pollination may begin as a neutral interaction and evolve towards parasitism.  

1 - University of Massachusetts Amherst, Graduate Programs in Organismic & Evolutionary Biology and Entomology, 204C French Hall, 230 Stockbridge Rd., Amherst, MA, 01003-9316, United States
2 - University of Massachusetts Amherst, Biology

Keywords:
gynodioecy
nursery pollination
pollination
Herbivory
floral traits
evolutionary ecology
plant-pollinator interactions
plant-insect interactions.

Presentation Type: Recent Topics Poster
Session: P, Recent Topics Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM
Number: PRT001
Abstract ID:1168
Candidate for Awards:None