Species differences in reproductive timing and egg load in two fly species adapted to different host plants

Selection acts on reproductive timing and egg number to maximize reproductive success based on available resources. Species often vary in these life history traits due to differences in trait variation and local selection pressures, especially when species are adapted to different environments. Yet, species may share similar life history traits given common correlations, such as a positive relationship between body size and fecundity. In this study, we tested whether species adapted to different environments differ in their reproductive timing and egg load using two species of Tephritid fruit flies: Rhagoletis pomonella adapted to downy hawthorn and Rhagoletis suavis adapted to black walnut. In both species, older females were more likely to produce eggs and have more eggs. However, reproductive timing differed between species; hawthorn flies produced eggs earlier than walnut flies. In contrast to the common association of larger body size with earlier reproduction and higher egg counts..., , , # Species differences in reproductive timing and fecundity in two fly species adapted to different host plants

[https://doi.org/10.5061/dryad.rr4xgxdhb](https://doi.org/10.5061/dryad.rr4xgxdhb)

## Description of the data and file structure

We collected wild flies as larvae in their host fruits (hawthorn and walnut) and reared them in environmental chambers in the lab until eclosion as adults. We housed adults until a series of sampled ages ranging from 10-58 days. Females were frozen and then measured for body length under a high magnification dissecting microscope. We then dissected the ovaries and counted eggs.

### Files and variables

#### File: Rhagoletis\_haw\_walnut\_fecundity\_to-publish.xlsx

**Description:** Body size and fecundity for hawthorn and walnut flies

##### Variables

* population (different 2-3 letter code for each population; WS and EL are in Michigan, LBL is in Kentucky, and CHE is in Colorado)
* expt (expt 1 or 2, methods described in the manuscript)
* fruit ...