Pea and Bean Weevils

Bruchinae

Classification

Pronunciation

How to pronounce Bruchinae: //ˈbruːkɪneɪ//

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

Images

Bruchus loti Paykull, 1800 by URSchmidt. Used under a CC BY-SA 4.0 license.
Fig 12 Musée entomologique illustré (6008159669) (cropped) by Bisson-Cottard (Firm); Depuiset, A.; Fischbach, Gustave; Poteau, J.; Quartley, J.; Rothschild, J.; Specht, Friedrich; Vizetelly, Henry. Used under a Public domain license.
Bruchus affinis (50824684812) by Gilles San Martin from Namur, Belgium. Used under a CC BY-SA 2.0 license.
Bruchus loti, Dee by Holt, North Wales, May 2018 by janetgraham84new. Used under a CC BY 2.0 license.
Bruchus pisorum by Natasha Wright, Florida Department of Agriculture and Consumer Services, Bugwood.org. Used under a CC BY 3.0 license.
Bruchus affinis Froelich, 1799 by URSchmidt. Used under a CC BY-SA 4.0 license.

Summary

Bruchinae comprises the bean weevils or seed beetles, characterized by their granivorous larvae that feed and pupate within seeds. They are approximately 1,650 species globally, with compact oval shapes and a tendency to infest various seeds, especially legumes.

Physical Characteristics

Compact and oval-shaped; typically 1 to 22 mm in size; colors usually black or brown with mottled patterns; small heads bent under; elytra are short, not reaching the tip of the abdomen.

Identification Tips

Check pygidium for diagnostic characters; examine elytra length relative to abdomen.

Habitat

Larvae feed inside seeds, typically found in legumes but also in Convolvulaceae, Arecaceae, and Malvaceae.

Distribution

About 1,650 species found worldwide, with specific records in North America and Great Britain; some introduced species exist in warehouses.

Diet

Granivorous; infest seeds or beans.

Life Cycle

Larvae develop inside seeds, pupating in the same location; adults oviposit on seeds, flowers, or young fruits.

Reproduction

Adults lay eggs on fully developed seeds; larvae bore into seeds after hatching.

Ecosystem Role

They play a role in seed dispersal and are considered pests for various agricultural crops.

Economic Impact

Several species are considered pests, affecting agriculture, especially in legumes and stored products.

Collecting Methods

  • Hand collection from host plants
  • Trapping using baited traps

Preservation Methods

  • Drying
  • Freezing
  • Storing in alcohol

Evolution

Formerly classified in the family Bruchidae, now recognized as a subfamily of Chrysomelidae; includes 24 genera.

Similar Taxa

Misconceptions

Often mistaken for true weevils due to compact shape; however, they lack the long snouts characteristic of true weevils.

Tags

  • Bruchinae
  • bean weevils
  • seed beetles
  • Chrysomelidae
  • granivores