Species-specific, age-varying plant traits affect herbivore growth and survival.

Seasonal windows of opportunity represent intervals of time within a year during which organisms have improved prospects of achieving life history aims such as growth or reproduction, and may be commonly structured by temporal variation in abiotic factors, bottom-up factors, and top-down factors. Although seasonal windows of opportunity are likely to be common, few studies have examined the factors that structure seasonal windows of opportunity in time. Here, we experimentally manipulated host-plant age in two milkweed species (Asclepias fascicularis and Asclepias speciosa) in order to investigate the role of plant-species-specific and plant-age-varying traits on the survival and growth of monarch caterpillars (Danaus plexippus). We show that the two plant species showed diverging trajectories of defense traits with increasing age. These species-specific and age-varying host-plant traits significantly affected the growth and survival of monarch caterpillars through both resource quality- and quantity-based constraints. The effects of plant age on monarch developmental success were comparable to and sometimes larger than those of plant-species identity. We conclude that species-specific and age-varying plant traits are likely to be important factors with the potential to structure seasonal windows of opportunity for monarch development, and examine the implications of these findings for both broader patterns in the ontogeny of plant defense traits and the specific ecology of milkweed-monarch interactions in a changing world

Data from: Adaptation to an invasive host is driving the loss of a native ecotype

Locally adapted populations are often used as model systems for the early stages of ecological speciation, but most of these young divergent populations will never become complete species. The maintenance of local adaptation relies on the strength of natural selection overwhelming the homogenizing effects of gene flow; however, this balance may be readily upset in changing environments. Here I show that soapberry bugs (Jadera haematoloma) have lost adaptations to their native host plant (Cardiospermum corindum) and are regionally specializing on an invasive host (Koelreuteria elegans), collapsing a classic and well-documented example of local adaptation. All populations that were adapted to the native host-including those still found on that host today-are now better adapted to the invasive host in multiple phenotypes. Weak differentiation remains in two traits, suggesting that homogenization across the region is incomplete. This study highlights the potential for adaptation to invasive species to disrupt native communities by swamping adaptation to native conditions through maladaptive gene flow

Experiment 3: Measuring the plastic effect of rearing host on adult morphology

Data collected from lab trials for J. haematoloma reared on the hosts K. elegans and C. corindum. This file includes data on morphology (beak length, thorax width, wing length), development time, sex, family, and ancestral location (population, latitude, host plant). Data is also included in this file for individuals from a third ancestral host, C. microcarpum, that is not reported on in the manuscript

J.haematoloma development times (F1 2014, F2 2014, F1 2013)

Development time from hatching to adulthood for J.haematoloma combined from 3 experiments. Column heading interpretation: Number=individual identifier (unique between experiments); Family=maternal identifier: NOT unique across experiments (explained in more detail below); bug.pop=location, city or island name, from which the individuals parents or grandparents were collected; host.pop=location, city or island name, from which natal host seeds were collected (not available for K.elegans in 2013); pophost=host species from which parents or grandparents were collected in the field; nathost=host species on which the individual was reared; hatch date=date an individual hatched (not available for 2013 data); eclosion date=date an individual reached adulthood (not available for 2013 data); sex=M is male, F is female; Dvpt.time=number of days after hatching before an individual reached adulthood; Experiment=which experiment the individual is from (F1 2014, F2 2014, or F1 2013); mate=identifier (Number) of the individual with whom each F1 2014 individual was mated (some individuals did not have suitable mates available or died before they became available; not applicable for F2 2014 or F1 2013 experiments). FAMILY elaboration: The family number for individuals in the F2 2014 experiment indicates the Number of the mother, all of whom were members of the F1 2014 experiment. Paternal identifiers can be determined from the mate of the mother. Family identifiers were reused between experiments

Data from Experiment 1: Testing natural selection in the lab

Data collected from lab feeding trials of Jadera haematoloma on opened and closed seedpods of C. corindum and K. elegans. This file includes data on adult morphology (beak length, thorax width, wing length, wing morph), family, population, host, feeding trial data (weight change, latency time, feeding time), and reproduction (egg number and mass). Seedpod treatments are abbreviated C and O (closed and open). Columns F1-F16 indicate whether or not an individual was feeding at each time point during the feeding trial; these are ordered chronologically. Some individuals do not have data for all 16 time points, depending on the length of the individual feeding trial. Latency time for individuals that never began feeding are labelled NA. There are some individuals included in this data file from a third host plant (C. microcarpum) that are not included in the manuscript

Data from: Maladaptive plasticity masks the effects of natural selection in the red-shouldered soapberry bug

Natural selection can produce local adaptation, but local adaptation can be masked by maladaptive plasticity. Maladaptive plasticity may arise as a result of gene flow producing novel gene combinations that have not been exposed to selection. In the 1980s, populations of the red-shouldered soapberry bug (Jadera haematoloma) were locally adapted to feed on the seeds of a native host plant and an introduced host plant; by 2014, local differentiation in beak length had been lost, likely as a consequence of increased gene flow. In this study, I assess the relative contributions of natural selection and plasticity to beak length on these two hosts. I confirm the earlier hypothesis that the host plant seedpod drives divergent natural selection on beak length. I then demonstrate that the proximate cause of the loss of observable differentiation in beak length is maladaptive plasticity, which masks persistent genetic differences between host-associated populations. Maladaptive plasticity is highest in areas where the two plants co-occur; in combination with historical measures of plasticity in hybrids, this indicates that maladaptive plasticity may be a consequence of ongoing gene flow. Although natural selection produced locally adapted genotypes in soapberry bugs, maladaptive plasticity is masking phenotypic differences between populations in nature

Experiment 2: Testing natural selection in the field

Data collected during field feeding trials for J. haematoloma on open and closed seedpods of C. corindum in Key Largo, FL in April 2014. This file includes data on morphology (beak length, thorax width, wing morph), feeding activity (latency time, feeding time), and flight ability. Seedpod treatments are abbreviated C and O (for closed and open pods). The flight.test column indicates whether or not flight behavior was observed when individuals were gently tossed into the air three times. Columns F1-F16 indicate whether or not an individual was observed feeding at each time point during the feeding trial; these are ordered chronologically

Simulated development time code

This file includes: 1) Code for data extraction of development times from Figure 3 of Carroll et al 1997; note that the exact pixel values will differ depending on how you size and crop the image. 2) Code for simulating 1000 (or however many you want) datasets using the means and standard deviations of 1988 and 2013-2014 data. 3) Code for statistical comparison of all 1000 datasets for the complete dataset and within each host plant. Code for model selection is not included (but could be added if requested)

J.haematoloma survival in 2014 (F1, cross-rearing experiment)

Survival data for J.haematoloma in cross-rearing experiment conducted on F1 laboratory generation in 2014. Column heading interpretation: Number=individual identifier (because the datasheet was generated before hatching, some numbers were not used for individuals that never hatched); Family=maternal identifier (field-collected, paternity uncertain); bug.pop=location, either city or island name, from which the parents of that individual were collected; host.pop=location, either city or island name, from which the natal host seeds for that individual were collected; pophost=host species from which parents were collected; nathost=host species on which that individual was reared; hatch date=date the individual hatched; eclosion date=date the individual reached adulthood; death date=date an individual died if they did not reach adulthood (mortality post-adulthood was generally not recorded); sex=M for male, F for female if individuals reached adulthood. Blanks and NAs indicate data types that were not collected