Phyllobius oblongus

European Snout Beetle

Phyllobius oblongus, European Snout Beetle photo

Family: Curculionidae

Subfamily: Brachycerinae

Length: 5-6 mm


An accidentally introduced species, Phyllobius oblongus was first noticed in upstate New York in 1923, collected from American Elm.

Adults feed on leaves and the tender shoots of orchard trees as well as Maple, Elm, Birch, Willow, and other hardwoods.

These beetles begin mating immediately after emerging from the soil, and the females oviposit about twelve days later. The eggs are laid 2-5 cm below the surface of the soil, and take take about thirty days to hatch. The larvae feed on fine roots and pass through five instars. They overwinter in the soil and pupate in the spring.

A study of forest weevils in portions of northern Wisconsin and Michigan found that of the weevil larvae collected, all were introduced species, with Phyllobius oblongus as one of the two or three most common. In this area numbers of adult Phyllobius oblongus peaked in the second half of June (Pinski et al., 2005).

Pinski and colleagues commented, "Exotic curculionids dominated the insect fauna in both the soil and on the understory foliage, and there was a surprising lack of native weevils in these habitats."

American Insects site