Pollen beetle

Meligethes aeneus

Overview:

Meligethes aeneus, commonly known as the Pollen Beetle or Rape Pollen Beetle, is a small beetle that can be a pest in oilseed rape (canola) crops. These beetles belong to the family Nitidulidae and can cause damage during the flowering stage of the host plant.

Detailed Appearance:

  • Adult beetles are small, usually around 2 to 4 millimeters in length.
  • They have an elongated and somewhat flattened body.
  • The coloration can vary but often includes metallic shades of green, blue, or bronze.
  • The antennae have eleven segments.

Life Cycle:

  • The life cycle includes egg, larva, pupa, and adult stages.
  • Adult beetles lay eggs in flowers.
  • Larvae feed on pollen and developing seeds.
  • Pupation occurs in the soil, and adults emerge.

Identification of Crop Infestation:

  • Presence of adult beetles on oilseed rape flowers during the flowering period.
  • Damage caused by feeding on pollen and developing seeds.
  • High population levels may result in economic losses.

Management Strategies:

  • Threshold Monitoring:

    • Regularly monitor fields for the presence of Pollen Beetles.
    • Economic thresholds help determine the need for control measures.

  • Cultural Controls:

    • Adjust sowing dates to minimize overlap with peak beetle activity.
    • Use trap crops to attract beetles away from main crops.

  • Biological Controls:

    • Encourage natural enemies such as parasitoid wasps and predatory beetles.
    • Conservation of natural predators helps regulate Pollen Beetle populations.

  • Chemical Controls:

    • Apply insecticides labeled for Pollen Beetle control when populations exceed economic thresholds.
    • Timing is crucial, focusing on the flowering stage.

  • Resistant Varieties:

    • Consider planting oilseed rape varieties with some level of resistance to Pollen Beetles.
    • Resistant plants can help reduce the impact of infestations.

  • Early Harvest:

    • Early harvest can help reduce the impact of Pollen Beetles on seed quality.
    • This may be particularly relevant if populations are high.

It's essential to integrate multiple management strategies and adapt them to local conditions. Regular monitoring, early intervention, and a well-balanced approach contribute to successful pest management in oilseed rape crops. For specific recommendations and the latest information, consult with local agricultural extension services or entomologists.