Bagous restrictus

Aquatic and semi-aquatic freshwater environments; specifically associated with waters infested by Hydrilla verticillata, a submerged aquatic plant. The species is tied to the presence of this host plant rather than specific water body types.

North America; specifically recorded from the southeastern United States. Distribution records include Canada (British Columbia, Nova Scotia, Ontario, Québec) and the United States, though the core native range appears centered in the southeastern U.S. where Hydrilla infestations occur.

Hydrilla verticillata (hydrilla) is the only known host plant. Adults feed on Hydrilla stems and tubers. Larvae feed internally within Hydrilla stems and develop within tubers.

• Hydrilla verticillata - obligateOnly known host; larvae develop in stems and tubers, adults feed on both structures

Egg to adult development completed within Hydrilla tissues. Larvae feed and develop inside Hydrilla stems and tubers. The species can complete development on both stems and tubers, though survivorship differs between tissue types.

Adult feeding damage observed on both Hydrilla stems and tubers. Lower survivorship on stems compared to introduced congeneric biological control agents; higher survivorship on tubers than on stems. Potential for competitive or complementary interactions with introduced Bagous hydrillae and B. affinis where ranges overlap.

Native herbivore of the invasive aquatic weed Hydrilla verticillata. Possible natural control agent for Hydrilla infestations, though effectiveness appears lower than introduced biological control agents on stems. May compete with or complement introduced biocontrol weevils in managed aquatic ecosystems.

Subject of biological control research due to its native status and exclusive association with the invasive weed Hydrilla. Studied alongside introduced Bagous species to assess relative efficacy and potential interactions in Hydrilla management programs.

• Bagous hydrillaeIntroduced biological control agent for Hydrilla; also completes development on Hydrilla stems and tubers but achieves higher survivorship on stems than B. restrictus
• Bagous affinisIntroduced biological control agent for Hydrilla; completes development on stems and tubers but lower tuber survivorship than B. restrictus

• Curculionidae
• Bagous
• Hydrilla
• biological control
• native
• aquatic weevil
• host specificity
• invasive plant management
• southeastern United States
• North America

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life
• Sphecidae | Beetles In The Bush
• Let’s make a deal! | Beetles In The Bush
• 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>)