Sciopithes obscurus

Horn, 1876

obscure root weevil

Sciopithes obscurus, commonly known as the obscure root weevil, is a broad-nosed weevil in the Curculionidae. are foliage feeders that sometimes remain in vegetation during daylight hours, an atypical among weevils. The is considered an agricultural pest in the Pacific Northwest, particularly affecting rhododendrons and strawberries. Larvae feed on roots after hatching, with one produced annually.

Pronunciation

How to pronounce Sciopithes obscurus: //ˌsaɪ.oʊˈpɪθ.iːz ɒbˈskjʊər.əs//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from similar broad-nosed weevils by the combination of small size (6–8 mm), gray-brown coloration with a wavy line, and short snout with elbowed positioned to the . The tendency of to remain in foliage during daytime, rather than descending to soil, separates it behaviorally from many congeneric and confamilial . Accurate identification may require examination of genitalia or comparison with reference specimens.

Habitat

Associated with agricultural and ornamental plantings, particularly strawberry fields and rhododendron plantings in the Pacific Northwest. occupy foliage of plants; larvae occur in soil around root systems.

Distribution

North America; documented from British Columbia, Washington, Oregon, and California. Core range centered in the Pacific Northwest.

Seasonality

One per year; activity occurs during growing season when plants are available. Specific seasonal timing of adult not documented in available sources.

Diet

feed nocturnally on foliage of plants. Documented hosts include strawberry (Fragaria) and rhododendron (Rhododendron). Larvae feed on roots immediately after hatching and descending into soil.

Host Associations

strawberry - food plantPrimary agricultural ; feed on foliage, larvae on roots
rhododendron - food plantImportant ornamental in Pacific Northwest

Life Cycle

Females deposit up to 100 either in leaf folds or in soil. Larvae hatch and immediately burrow into soil to feed on roots. One per year; stage not specified in available sources.

Behavior

feeding on foliage. Unlike most weevil , frequently remain in vegetation during daylight hours rather than climbing down to seek shelter in soil or leaf litter. This behavioral trait increases visibility to observers and may affect control strategies.

Human Relevance

Agricultural and horticultural pest in the Pacific Northwest. Damage to strawberry and rhododendron crops necessitates management. Susceptibility to cyclodiene has been documented, with potential variation based on plant nitrogen nutrition.

Similar Taxa

Brachyrhinus sulcatusBlack vine weevil; similar root-feeding and strawberry association, but distinguished by greater sensitivity to nitrogen nutrition effects on and differential susceptibility to cyclodiene

More Details

Pest Management Note

appears less sensitive to plant nitrogen nutrition compared to Brachyrhinus sulcatus, suggesting -specific responses to fertilizer regimes may affect