Major Radish Pests and Damage Symptoms: Worldwide Overview

Overview

This report summarizes the principal insect pests and diseases affecting radish (Raphanus sativus) worldwide, with emphasis on damage symptoms recognized in field production. Radish is grown for its swollen taproot and is vulnerable to both foliar and root-feeding pests from emergence through harvest.

Insect Pests

1. Flea Beetle (Phyllotreta spp.)

• Damage: Adults chew small round holes ("shot holes") in cotyledons and true leaves. Severe early infestation can stunt seedlings and reduce stand establishment.
• Distribution & Characteristics: One of the most common early-season pests of brassica-family roots and leafy crops, including radish.

2. Root Maggot / Cabbage Root Fly (Delia spp.)

• Damage: Larvae tunnel into radish roots, causing brown feeding channels, rot, and unmarketable produce. Wilting and poor root development are common aboveground symptoms.
• Distribution & Characteristics: A major root pest of radish and other brassicas in temperate regions; damage is often worse in cool, moist seasons.

3. Aphids (Myzus persicae and others)

• Damage: Colonies on leaves reduce photosynthesis and may transmit viruses. Honeydew promotes sooty mold and lowers market quality.

4. Cutworms and Armyworms

• Damage: Larvae cut seedlings at the soil line or feed on foliage, causing irregular stand loss shortly after emergence.

Major Diseases

Clubroot (Plasmodiophora brassicae)

• Damage: Swollen, distorted roots with poor taproot development and severe yield loss in infested fields.

Downy Mildew (Hyaloperonospora parasitica)

• Damage: Yellow leaf spots with grayish fungal growth on the underside; defoliation reduces root sizing.

Sources

Compiled from international extension guides on brassica root crops, radish pest management references, and peer-reviewed summaries of Raphanus sativus production pests.