PS 27-82 - Intelligent egg laying: analysis of plant traits and chemistry underlying both oviposition choice and larval growth of seed predator Schinia florida on the common evening-primrose (Oenothera biennis)

Tuesday, August 16, 2022

5:00 PM – 6:30 PM EDT

Located in: ESA Exhibit Hall

Presenting Author(s)

KS

Kelley Slimon

Ph.D. Student
Cornell University, New York, United States

Coauthor(s)

AA

Anurag Agrawal

Cornell University, United States
JS

Juha-Pekka Salminen

University of Turku, Finland
SM

Scott McArt

Professor
Cornell University, New York, United States

Background/Question/Methods

Oviposition choice and larval performance are essential metrics that determine the outcome of plant-herbivore interactions. If herbivores can identify plant traits that optimize offspring survival, traits that are predictive of larval performance should also be predictive of oviposition choice. To test this theory, this experiment measured an oviposition choice and larval performance of the seed predator Schinia florida on the common evening primrose (Oenothera biennis) as well as an extensive set of plant traits and chemistry. Specifically, we measured 14 plant traits, and quantified concentration of 66 phenolic metabolites within buds and fruits (both tissues used for oviposition). Phenolics measured included ellagitannins, flavonoids, and caffeic acid derivatives known to affect insect herbivory in O. biennis. Additionally, previous work suggests that chemical traits differ significantly between distinct O. biennis genotypes. This study was conducted across 28 O. biennis genotypes (164 total plants) to test the existence of a genotypic determinant of S. florida oviposition preference and larval performance.

Results/Conclusions

Of the 14 morphological traits measured, 7 were predictive of oviposition and 2 were predictive of RGR. Two traits, plant height, and density of glandular trichomes were predictive of both oviposition and RGR. Contrary to the hypothesis that herbivores should choose to oviposit on plants likely to benefit larval growth, S. florida prefers to oviposit on plants with more glandular trichomes, a trait associated with reduced growth rate of S. florida larvae. Additionally, oviposition choice and RGR did not vary with genotype as hypothesized. Preliminary analysis of phenolic data suggests that there are 8 compounds that best predict oviposition choice, 5 that best predict RGR, and two overlapping compounds (both kaempferol glycosides). Similar to the morphological traits, these overlapping compounds appear to have inverse effects on RGR and oviposition rate. These unanticipated results there seem to indicate a preference-performance trade-off. One hypothesis is that this tradeoff is a result of S.florida adults trying to oviposit on plants that maximize enemy-free space.