Data from: Evolution of male courtship behavior among species of parasitoids in the genus Aphelinus (Hymenoptera: Aphelinidae)

We compared male courtship behavior among parasitoid species in the genus Aphelinus. Male Aphelinus antennate in alternating bouts of waving and simultaneous dipping. Among species, durations of courtship rounds varied, and within these rounds, durations of dipping and waving bouts varied. Furthermore, number of dipping bouts, dips per bout, and positions of male antennae during courtship varied among species. Logistic regression of species on these components of male behavior correctly classified males to species with 95 percent accuracy. Mapping these courtship components onto a molecular phylogeny showed that antennal positions tended to be phylogenetically conserved, whereas antennation durations and numbers of bouts diverged when clades diverged. The overall phylogenetic signal was weak. Comparison of behavioral components between allopatric and sympatric species, controlling for phylogenetic distance, showed little evidence for reinforcement in sympatry.

Data are presented on parasitoid and host aphid species sampling locations, courtship behavior, and geographical patristic distance.

• Resource Title: collection_data.

  File Name: collection_data.csv

  Resource Description: Parasitoids in nine species of Aphelinus were collected from four aphid species on six plant species in six countries. The parasitoids were shipped or hand-carried as mummified aphids to the containment facility at the USDA-ARS, Beneficial Insect Introductions Research Unit, Newark, Delaware, and maintained under the permits indicated in the dataset. Vouchers for these populations are maintained at -20°C in 100% molecular-grade ethanol at the Beneficial Insect Introduction Research Unit, Newark, Delaware.




• Resource Title: courtship_behavior_data.

  File Name: courtship_behavior_data.csv

  Resource Description: We observed couples for 5 minutes or until courtship started and ended. This meant that observations could extend beyond 5 minutes, if courtship started before 5 minutes but ended later than 5 minutes. Observation arenas were made using two microscope slides with vinyl-foam weather-stripping (5 mm thick) glued to them; on one slide, the weather-stripping had a 10 mm diameter hole bored in it, exposing the slide surface through which observations were made. After observations in which copulation was observed, females were dissected to see whether sperm was transferred. In all dissections, females that copulated carried sperm, thus courtship rounds that led to copulation were considered successful. We recorded behavior using a binocular stereomicroscope (model SMZ 1500, Nikon Instruments, Melville, NY, USA) with a digital camera (model DEI 750D, Optronics, Goleta, CA, USA) connected to a digital video-tape recorder (model HVR-M15AU, SONY, New York, NY, USA) that provided date/time stamps and a DVD recorder (model DMR-EZ28K, Panasonic, Newark, NJ, USA). Video-editing software (Handbrake, version 0.9.9.5530) was used to convert DVD files from VOB to MP4 format. Video-analysis software (Kinovea, version 0.8.15) was used for playback of the observations to determine antennal positions and durations of courtship components. Durations of courtship rounds were measured from the start of male antennation until the end of copulation. The durations of the two types of male antennation (simultaneous dipping and alternate waving) were measured to the nearest tenth of a second. We counted the number of dipping bouts and waving bouts per courtship round, and for dips, we counted the number of dips per dipping bout. Antennal spread at the top and bottom of dips was classified as intraocular, mideye, head or greater than head relative to the width of the female head. Position of male to female antennae at the bottom of dips was classified as above, equal to or below the female antennae. Often the male antennae were close together at the top of the dip and the separation widened as male antennae approached female antennae. The shape of the dip was classified by the change in spread between the top and bottom of the dip as inward (closer at bottom than top), straight (no change), slight (change in one category, e.g. mideye to head width), or large (change in more than one category, e.g. intraocular to greater than head width). Therefore, we measured multiple components of courtship, five of which were categorical and eight of which quantitative, either continuous or discrete.




• Resource Title: data_dictionary_Aphelinus_courtship_behavior.

  File Name: data_dictionary_Aphelinus_courtship_behavior.csv

  Resource Description: Data dictionary for experiments on courtship behavior of nine Aphelinus species.




• Resource Title: geographical_patristic_distance_data.

  File Name: geographical_patristic_distance_data.csv

  Resource Description: Geographical distributions of these species are difficult to determine because of limited sampling and confusion in identification of closely related species. However, we used our collection data and reports from the literature to make our best determination of allopatry versus sympatry for all pairs of species.