Are day-flying moths more specialised in larval dietary breadth?

Although diurnality is widespread across Lepidoptera and has evolved many times independently, its causes and ecological implications are yet poorly understood. The ‘Salient Aroma Hypothesis’ (SAH) postulates that diurnal insect herbivores are overall more specialised in dietary breadth than species active at night. It is furthermore assumed that diurnality evolved more frequently in species that live in cooler environments. Using European geometrid moths as a model group, we tested whether diurnal activity in adults is associated with an increased larval dietary breadth as predicted by the ‘Salient Aroma Hypothesis.’ We further investigated whether species that exclusively occur in colder regions or whose flight period is restricted to cool seasons are more likely to exhibit a diurnal flight activity. Contrary to expectation, we found no consistent differences in larval dietary breadth between diurnal and nocturnal species, and thus no support for the ‘Salient Aroma Hypothesis.’ Diurna...,
The following were the methods used to obtain data for this study:

Literature search
Online database search
Personal field observations

, , # Are day-flying moths more specialised in larval dietary breadth?

[https://doi.org/10.5061/dryad.n5tb2rc3j](https://doi.org/10.5061/dryad.n5tb2rc3j)

Trait data was used to investigate relationships between diel activity and larval dietary breadth in European geometrid moths. The data set provides data compiled based on available sources (literature, databases, pers. field observations).

## Description of the data and file structure

1: Trait dataset in \"csv\"-file format that contains the following information for European geometrid species:

+**Taxonomy**: *Subfamily* & *Species*

+**Diel activity_I** (four categories): *diurnal*, *primarily* *diurnal*, *primarily* *nocturnal*, *nocturnal*

+**Diel activity_II** (binary coded): *diurnal* vs. *nocturnal*

+**Phenology** (binary coded): *cold-season species* (1) vs. *others* (0); cold-season species are defined as species that fly exclusively early (spring) or late (late autumn/ winter) in the year

+**Occurence** (binary coded): ...