What is the name of the flea that attacks cabbage? - briefly
The pest is the crucifer flea beetle (Phyllotreta cruciferae). It feeds on cabbage leaves, creating characteristic shot‑hole damage.
What is the name of the flea that attacks cabbage? - in detail
The insect commonly referred to as the cabbage flea is actually a flea beetle, scientifically named Phyllotreta cruciferae. It belongs to the family Chrysomelidae, subfamily Alticinae. Adults are small, 1.5–3 mm long, with a black or dark brown body and a shiny, metallic sheen. Their hind legs are enlarged for jumping, resembling true fleas, which gives rise to the common name.
Identification features
- Size: 1.5–3 mm, easily overlooked on foliage.
- Color: dark, often with a metallic gloss; some specimens show faint yellowish markings.
- Legs: markedly enlarged hind femora for rapid jumps.
- Antennae: short, filiform.
Life cycle
- Adults emerge in early spring, feed on young cabbage leaves, and lay eggs in the soil.
- Eggs hatch in 5–10 days, releasing larvae that remain underground and feed on rootlets.
- Larvae pupate in the soil, completing development within 2–3 weeks.
- Multiple generations may occur in a single growing season, depending on temperature.
Damage to cabbage crops
- Adults create small, round pits (shot‑hole damage) on leaf surfaces, reducing photosynthetic area.
- Heavy infestations lead to leaf bronzing, premature wilting, and increased susceptibility to pathogens.
- Larval feeding on roots can stunt plant growth and lower yield.
Management strategies
- Cultural: rotate crops with non‑cruciferous plants, avoid planting cabbage after previous infestations, and maintain weed-free borders to eliminate alternate hosts.
- Mechanical: apply floating row covers early in the season to exclude adults; remove and destroy infested plant debris.
- Chemical: use seed treatments containing neonicotinoids or pyrethroids where permitted; apply foliar insecticides targeting adult beetles when thresholds are exceeded.
- Biological: introduce natural predators such as ladybird beetles (Coccinellidae) and parasitic wasps (Braconidae); employ entomopathogenic fungi (e.g., Beauveria bassiana) for larval control.
Monitoring involves weekly visual inspections and sticky traps to assess adult populations. Economic injury levels are typically reached when more than 10 % of leaf area shows shot‑hole damage, prompting intervention. Timely application of integrated measures reduces the flea beetle’s impact and safeguards cabbage production.