Weeds, Insects & Diseases

Bean leaf beetle [Cerotoma trifurcata], Coleoptera


Insect Biology

Adults overwinter in leaf litter or other vegetation, primarily in or near wooded areas. They become active in April and move to the earliest host plant available. They feed for several days, then mate. Each female lays 175 to 250 eggs in clusters of...


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Description

Larvae are whitish with dark brown markings at both ends. The larvae also have conspicuous segments and six tiny legs near the head. These larvae/worms grow to a length of about 10 mm. The pupae are soft-bodied, white, and only about 5 mm long.


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Management

Recommended management practices include:

  • In fields with a history of injury, delay planting to the end of May/beginning of June after the emergence of the overwintering beetles. Be cautious as later-planted fields may be susceptible to late...


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Recommended solution

  • Fortenza logo

  • Endigo logo

  • Matador logo

  • Cruiser Maxx Vibrance Beans logo

Insect Biology

Adults overwinter in leaf litter or other vegetation, primarily in or near wooded areas. They become active in April and move to the earliest host plant available. They feed for several days, then mate. Each female lays 175 to 250 eggs in clusters of 12 to 24 in the soil at the base of plants. Eggs hatch in one to three weeks, depending on the temperature. The larvae find their way to the base of the stem or roots and feed for 3 to 6 weeks. Mature larvae form earthen cells within which pupae form. Damage to soybeans is due primarily to the foliar-feeding adults. Bean leaf beetles prefer the youngest plant tissue available. When vegetative growth terminates, they will consume tender pod tissue. Pod damage is usually limited to the outer layers of the pod. Damage is usually greatest in July and August. In addition to this beetle's direct attack, these adults are also known vectors of the bean pod mottle, cowpea mosaic, and southern bean mosaic viruses. The larvae can also cause some damage, as they feed on the root and stem tissue.

Description

Eggs are lemon-shaped, orange in colour, and about 0.85 mm long.

Larvae Description

Larvae are whitish with dark brown markings at both ends. The larvae also have conspicuous segments and six tiny legs near the head. These larvae/worms grow to a length of about 10 mm. The pupae are soft-bodied, white, and only about 5 mm long.

Adult Description

The adult bean leaf beetle varies greatly in colour and markings. It is typically reddish-brown with black margins and about 5 to 6 mm long. Each wing cover usually, but not always, is marked with three or four black spots. All bean leaf beetles, however, have a black triangular-shaped spot on the forward margin of the wings.

  • Red bean leaf beetle
  • Red bean leaf beetle
  • Bean leaf beetle
  • Pod & leaf damage

Management

Recommended management practices include:

  • In fields with a history of injury, delay planting to the end of May/beginning of June after the emergence of the overwintering beetles. Be cautious as later-planted fields may be susceptible to late-season pod feeding from first generation adults.
  • Use insecticide seed treatments in those fields with a history of early-season seedling infestations or to reduce vector abundance when planting food-grade soybeans to reduce bean pod mottle virus incidence.
  • Well-timed foliar insecticides are warranted when defoliation or pod feeding thresholds are reached.
Source
http://www.omafra.gov.on.ca/english/crops/pub811/pub811.pdf

Recommended solution

  • Fortenza logo

    Fortenza® insecticide is a non-neonicotinoid seed treatment for control of European chafer, June beetle, wireworm, and seedcorn maggot.                                                          

  • Endigo logo

    With a superior forumlation and two proven active ingredients, Endigo gives fast knockdown and residual control of soybean aphids and bean leaf beetles in your soybean field.                                                          

  • Matador logo

    Matador® 120EC insecticide protects a wide range of crops from insect damage that can rob you of yield and quality.                                                          

  • Cruiser Maxx Vibrance Beans logo

    Give your soybeans the Seedcare™ they deserve