Tychius picirostris

(Fabricius, 1787)

Clover Seed Weevil

Tychius picirostris is a small weevil in the Curculionidae, native to Europe and introduced to North America where it has become widespread. The is commonly known as the Clover Seed Weevil due to its association with clover plants (Trifolium spp.). It was first described by Fabricius in 1787 and has since been recorded across the Palaearctic region, including more recent documentation in China. As a seed-feeding , it represents one of several Tychius species that have established outside their native range through human-mediated .

Tychius picirostris by (c) Barry Walter, some rights reserved (CC BY), uploaded by Barry Walter. Used under a CC-BY license.

Tychius-picirostris-03-fws by Francisco Welter-Schultes. Used under a CC0 license.

Pronunciation

How to pronounce Tychius picirostris: /ˈtɪkius pɪkɪˈrɒstrɪs/

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Identification

Tychius picirostris can be distinguished from other introduced North American Tychius by plant association and morphological characters detailed in taxonomic keys. It differs from T. cuprifer, which is restricted to Maryland and associated with Teline monspessulana in addition to Trifolium; from T. meliloti, which feeds on Melilotus spp.; and from T. stephensi, which also uses Trifolium but has distinct morphological features. Specific diagnostic characters include details of the rostrum, , tibia, and genitalia as illustrated in taxonomic revisions.

Images

Habitat

Agricultural and natural supporting plants in the Trifolium, including clover fields, meadows, and grasslands.

Distribution

Native to Europe; introduced and widespread in North America. Recorded in China as a new Palaearctic country record. Also present on Atlantic islands including the Azores (Pico, Santa Maria, Terceira).

Diet

Seed-feeding ; larvae and develop in association with Trifolium spp. (clovers).

Host Associations

Trifolium spp. - plantPrimary ; larvae develop in seeds

Ecological Role

Seed of clovers (Trifolium), potentially affecting plant and seed production in agricultural and natural settings.

Human Relevance

Agricultural pest of clover seed crops; introduced to North America, likely through accidental transport with agricultural materials.

Similar Taxa

Tychius stephensiAlso introduced to North America and associated with Trifolium spp.; distinguished by morphological characters in taxonomic keys
Tychius cupriferIntroduced to North America but restricted to Maryland; differs in range including Teline monspessulana
Tychius melilotiIntroduced to North America; distinguished by association with Melilotus spp. rather than Trifolium

More Details

Taxonomic history

First described by J.C. Fabricius in 1787. The has been subject to multiple taxonomic revisions, most recently in comprehensive treatments of the Tychius in China and North America.

Introduction pathway

Introduced to North America from Europe, likely through transport of clover seed or hay; now established across the continent.