[14] As immatures (larvae), C. aeneicollis individuals use chemicals extracted from host plant foliage to produce a defensive secretion that they expose when attacked by potential predators.

[16] The evolutionary significance of the host-plant derived defensive secretions of C. aeneicollis was investigated, with the expectation that larval survival would be greater on salicylate-rich plants than salicylate-poor ones.

[15] Field studies on C. aeneicollis revealed that specialist predators cause significant mortality, which reduces or eliminates the benefits of the host-plant derived larval defensive secretion.

[20][21] These two predators act as complementary mortality factors on C. aeneicollis larvae and constitute important components of a food web including the beetle and its natural enemies in the Sierra Nevada mountains of California.

[20] Furthermore, populations at high elevations must complete their life cycle under conditions of low oxygen supply, which compounds the challenges of rapid development during the brief montane summer.

Populations in the eastern Sierra Nevada mountains show genetic differences along a latitudinal gradient that may reflect adaptation to variable temperatures and oxygen levels.