Data from: Ontogeny of color development in two green-brown polymorphic grasshopper species
Data files
Oct 31, 2023 version files 6.96 MB
-
README.md
-
ReflectanceAnalysis_ReadMe.txt
-
ReflectanceDataExcluded.csv
-
ReflectanceDataIncluded.csv
-
TernaryPlot_ReadMe.txt
-
TernaryPlotData.xlsx
Abstract
Many insects, including several orthopterans, undergo dramatic changes in body coloration during ontogeny. This variation is particularly intriguing in gomphocerine grasshoppers, where the green and brown morphs appear to be genetically determined (Schielzeth & Dieker, 2020; Winter, Varma, & Schielzeth, 2021). A better understanding of how these color morphs develop during ontogeny can provide valuable insights into the evolution and ecology of such a widespread color polymorphism. Here, we focus on the color development of two green-brown polymorphic species, the club-legged grasshopper Gomphocerus sibiricus and the steppe grasshopper Chorthippus dorsatus. By following the color development of individuals from hatching to adulthood, we found that color morph differences begin to develop during the second nymphal stage, are clearly defined by the third nymphal stage, and remain stable throughout the life of an individual. Interestingly, we also observed that shed skins of late nymphal stages are identifiable by color morphs based on their yellowish coloration, rather than the green that marks green body parts. Furthermore, by assessing how these colors are perceived by different visual systems, we found that certain potential predators can chromatically discriminate between morphs, while others may not. These results suggest that the putative genes controlling color morph are active during the early stages of ontogeny, and that green color is likely composed of two components, one present in the cuticle and one not. In addition, the effectiveness of camouflage appears to vary depending on the specific predator involved.
README
There are readme files for all datasets.
Methods
There are two sets of data:
1) Data from spectrometric reflectance measurements of grasshoppers (recorded with a handheld spectrophotometer, AvaSpec-2048, Avantes). The data from the recording device have been compiled into 2 tables (1. included in the analysis and 2. excluded from the analysis). The data are ready for analysis using the pavo package in R. Each row refers to a wavelength (given in the first column) and all other columns refer to individual data sets (reflectance of a particular body part at a particular wavelength). The attributes of the data sets are encoded in the column headers (see the ReflectanceAnalysis_ReadMe file for details).
2) Data from color measurement analysis of standardized images of the lateral side of the head for grasshopper individuals. We used ImageJ software to measure the red, green, and blue (RGB) values of the images. Using the polygon selection tool in ImageJ, two random areas were selected: one on the lateral lobes of the pronotum and another on the lateral side of the head. The average RGB value of these selected areas was measured. This data set is ready to plot the ternary plot in R. See the TernaryPlot_ReadMe file for details.