Hatching intervals of two eggs kept in contact with one another (top panel), separated by 3–5 mm (middle panel), or separated by a screen (bottom panel) in the six indicated grasshopper species. Eggs were maintained under continuous illumination and 30°C temperature (A–F.). Different letters indicate significant differences in mean values at the 5% level using the Steel-Dwass test. Diagram on the right shows how the eggs were arranged in wells.