Sexual size dimorphism (SSD) and sexual shape dimorphism (SShD) are of interest to evolutionary ecology, but the two phenomena can very easily be conflated by not taking a multivariate approach to measuring size. In our study we draw attention to this problem by measuring four body size dimensions (maxillae span, head width, pronotum length and mean hind femur length) in lab-reared individuals of the badlands cricket (Orthoptera, Gryllinae, Gryllus personatus) and conducting a variety of multivariate analyses to test whether there is SSD and/or SShD.

We found that males had wider heads and maxillae than females, and females had longer pronota and hind femora than males. This difference in the direction of sexual dimorphism indicates SShD. However, multivariate methods failed to detect SSD, instead confirming that the sexes primarily differ in body shape. We suggest that orthopterists studying sexual dimorphism minimally measure head width, pronotum length and hind femur length as a standard that will allow a more repeatable and generalizable assessment of the prevalence and direction of both SSD and SShD.

The attached dataset consists of: 1) all of the photographs (*.jpg) from which the measurements were taken, 2) a reference photograph (ReferenceScale2mm_WildM56X.jpg) of a 2-mm-long stage micrometer taken with the same microscope (Wild M5) and at the same magnification (6X), and 3) a spreadsheet (*.csv) containing our measurements, which form the basis for analyses in our published article.

Photographs were prepared by dissecting individual crickets that had been euthanized by freezing, and placing them in standardized positions under a Wild M5 stereomicroscope as in Judge and Bonnano 2008 (https://doi.org/10.1371/journal.pone.0003980). Images were taken with a digital camera (Infinity Lumenera) as in Dupuis et al. 2020 (https://doi.org/10.1093/biolinnean/blaa094). Landmarks (see Figure 1 in Judge and Bonanno 2008, https://doi.org/10.1371/journal.pone.0003980) were placed on the photos using SB Morphometrics (http://life.bio.sunysb.edu/morph/index.html) and converted to linear measurements as described in Dupuis et al. 2020.  Photograph files have a consistent naming system of five letters, three numbers, and then one or two letters. For example, GPEFA001FL.jpg, where GPE is consistent for all and refers to the species, F means the individual is female (M for male), A means the individual is an adult (J for juvenile), 001 is individual 1 (ranges from 001 to 168), and FL means femur left indicating the photo subject (other subjects: FR for femur right, HP for head posterior, and P for pronotum).

Image files can be opened and landmarks placed with the freely available SB Morphometrics (http://life.bio.sunysb.edu/morph/index.html). The data csv file is accessible by most spreadsheet programs.