Final answer:
There is less genetic variation for larval group defense than for elytra length.
Step-by-step explanation:
The given data shows the narrow-sense heritability (H₂) for larval group defense is 0.1, while the H₂ for elytra length is 0.5.
From these data, we can conclude that there is less genetic variation for larval group defense than for elytra length. This means that the genetic factors play a smaller role in determining the variation in larval group defense compared to the variation in elytra length.