Southern chinch bug

Blissus insularis

1. Identification

• Common name: Southern chinch bug
• Scientific name: Blissus insularis Barber
• Order: Hemiptera
• Family: Blissidae

2. Pest description

• Small adults (4–5 mm), narrow body and light to dark brown coloration.
• Nymphs of lighter coloration, changing from orange-yellow to brown.
• Piercing-sucking mouthpart, feeding on the sap of the grasses.
• Generally found at the base of the plants, close to the soil.
• Rapid movement and gregarious behaviour.

3. Main hosts

• Lawns and ornamental grasses, especially: Stenotaphrum secundatum (St. Augustine grass) (main host); Other warm-climate grasses.
• May occur in gardens, sports fields and urban areas with lawns.

4. Symptoms and damage

• Irregular yellowish patches on the lawn, which evolve into brown tones.
• Drying and death of tufts of grass.
• Damage begins at the base of the plants, hindering early detection.
• In severe attacks, large areas of the lawn are destroyed.
• Increased susceptibility to water and thermal stress.

5. Biological cycle

• Multiple generations per year in hot climate.
• Eggs laid at the base of the plants or in the soil.
• Nymphs develop through 4–5 instars before reaching the adult stage.
• Cycle favoured by high temperatures and low soil moisture.
• Populations reach peaks in summer and early autumn.

6. Monitoring

• Observation of initial yellowish patches on the lawn.
• Inspection of the base of the plants to detect nymphs and adults.
• Shaking the grass over a white tray to facilitate viewing.
• Intensive monitoring during the summer.
• Assessment of population density to determine the need for intervention.

7. Management measures

• Cultural: increasing the cutting height, improving irrigation, removing accumulated thatch and promoting vigorous lawns.
• Biological: conservation of natural predators and use of entomopathogens when authorised.
• Integrated protection: regular monitoring, targeted interventions only when necessary, judicious use of authorised insecticides and integration with cultural practices to reduce population pressure.

Bibliographic references

• EPPO Global Database – Blissus spp..
• CABI Invasive Species Compendium – B. insularis.
• Reinert, J. A. et al. (2011). Biology and management of southern chinch bug..
• Kerr, S. H. et al. (1966). Damage and ecology of Blissus insularis in turfgrass
• DGAV – Phytosanitary Alert: Presence of Blissus insularis in Portugal (2023).
• DGAV – Exceptional Emergency Authorisation 2023/18 for the control of Blissus insularis in lawns [Art.º 53 of Reg. (EC) 1107/2009].