Pachnaeus opalus

(Olivier, 1807)

Northern Citrus Root Weevil

Pachnaeus opalus is a broad-nosed weevil in the Curculionidae, commonly known as the northern citrus root weevil. It is native to the southeastern United States and has been documented in Alabama, Florida, Georgia, Mississippi, and New Jersey. The is associated with citrus and related plants, where feed on foliage and larvae develop in roots. It was first described by Olivier in 1807 as Curculio opalus.

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Pronunciation

How to pronounce Pachnaeus opalus: //pækˈniːəs ˈɒpələs//

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Identification

Distinguished from other Pachnaeus by geographic distribution and subtle morphological characters. Pachnaeus litus (southern citrus root weevil) occurs in overlapping regions; precise identification requires examination of genitalia or other detailed morphological features not specified in available sources.

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Habitat

Associated with citrus groves and areas where citrus and related Rutaceae plants grow. are found on plants; larvae occur in soil around root systems.

Distribution

Southeastern United States: documented from Alabama, Florida, Georgia, Mississippi, and New Jersey. The northernmost records in New Jersey suggest range extension or isolated .

Diet

feed on citrus foliage; larvae feed on citrus roots. The specific feeding habits are inferred from the and association, though direct documentation for this is limited.

Host Associations

Citrus - primary feeding on foliage, larval development in roots

Life Cycle

Complete with , larva, pupa, and stages. Larvae are root-feeders in soil; adults emerge to feed on foliage. Specific timing of life stages is not documented in available sources.

Behavior

are likely or feeders, typical of many Entiminae weevils. When disturbed, adults may drop from foliage to the ground. capability is reduced or absent, as is common in broad-nosed weevils.

Ecological Role

As a root-feeding herbivore, larvae may influence plant vigor and nutrient uptake in citrus. impacts are most significant in agricultural contexts rather than natural .

Human Relevance

Recognized as a pest of citrus in the southeastern United States. Root feeding by larvae and foliar feeding by can reduce tree health and productivity. Management may be required in commercial citrus operations.

Similar Taxa

Pachnaeus litusSouthern citrus root weevil with overlapping range; distinguished by distribution and subtle morphological differences requiring expert examination
Pachnaeus citusAnother citrus-associated ; identification requires detailed morphological comparison

More Details

Taxonomic history

Originally described as Curculio opalus by Olivier in 1807, later transferred to Pachnaeus. The genus Pachnaeus contains multiple citrus-feeding that are economically significant in the southeastern United States.