Bagous

Semi-aquatic and aquatic environments, particularly those supporting submerged aquatic vegetation such as Hydrilla verticillata. Species occupy habitats ranging from freshwater lakes and ponds to slow-moving waterways where host plants occur.

Widespread distribution with records from Europe (Denmark, Norway, Sweden), North America (United States including Vermont), and Australia. Specific species have been introduced to new regions as biological control agents; for example, Bagous hydrillae was introduced from Australia to Florida, USA in 1991.

Multiple species feed on Hydrilla verticillata, including stems, tubers, and submerged leaves. Bagous hydrillae larvae mine hydrilla stems while adults feed on stems and submerged leaves. Host specificity varies among species; some complete development on hydrilla while others do not.

• Hydrilla verticillata - primary hostStems, tubers, and submerged leaves; supports complete development of B. hydrillae and B. affinis

Larvae develop within plant stems; for Bagous hydrillae, single eggs are laid in hydrilla stems and three larval instars develop within. Development from egg to adult takes 12–14 days at 25°C. Pupation occurs on floating plant fragments or those stranded on shorelines.

Larvae and adults feed beneath the water surface, fragmenting stems. Feeding continues on floating fragments and stranded material. Some species exhibit higher survival and fecundity on tubers compared to stems. Extensive host-specificity testing has been conducted for species considered as biological control agents.

Several species serve as biological control agents for invasive aquatic weeds, particularly Hydrilla verticillata. Native species such as B. restrictus may occupy similar habitats without contributing to control of target weeds.

Used as biological control agents for management of invasive hydrilla in the United States. Bagous hydrillae was introduced to Florida in 1991 after extensive host-specificity testing. B. affinis has also been introduced for hydrilla control.

• Bagous australasiaeSimilar morphology; distinguished by figures and descriptions in taxonomic literature for species identification

• weevil
• aquatic
• biological control
• Hydrilla
• invasive species management
• Curculionidae
• semi-aquatic
• stem miner

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Hydrilla Stem Weevil: Bagous hydrillae O’Brien
• Hydrilla Stems and Tubers as Hosts for Three Bagous Species: Two Introduced Biological Control Agents (Bagous hydrillae and B. affinis) and One Native Species (B. restrictus)
• Hydrilla Stems and Tubers as Hosts for Three <I>Bagous</I> Species: Two Introduced Biological Control Agents (<I>Bagous hydrillae</I> and <I>B. affinis</I>) and One Native Species (<I>B. restrictus</I>)
• Host Range Studies with Bagous affinis (Coleoptera: Curculionidae), an Indian Weevil that Feeds on Hydrilla Tubers
• First Descriptions of Larva and Pupa of Bagous claudicans Boheman, 1845 (Curculionidae, Bagoinae) and Systematic Position of the Species Based on Molecular and Morphological Data
• DISTRIBUTION AND BIOLOGY OF A NEW BAGOUS WEEVIL (COLEOPTERA: CURCULIONIDAE) WHICH FEEDS ON THE AQUATIC WEED, HYDRILLA VERTICILLATA