Obscure weevil is mainly gray with a wavy brown line across the back near the rear. Larvae of all species of root weevils are superficially similar in appearance except for size. They are legless grubs with white bodies and brown heads. It is very soft and has the outlines of the parts of the adult weevil. The life history is similar for all species.
Winter is spent as a larva in the soil feeding on plant roots.
In April or May it changes to the pupa, which does not feed. Further transformation to the adult stage occurs in late May and early June. Adults feed on plant foliage and begin to lay eggs 4-6 weeks after emergence. Otiorhynchus weevils lay their eggs on the soil, but the obscure root weevil lays its eggs on the leaves. Larvae which emerge from the eggs burrow into the soil to feed on the roots.