Banana Rust Thrips (Chaetanaphothrips signipennis) – Damage and Life Cycle

Introduction
Banana rust thrips (Chaetanaphothrips signipennis) are a serious pest of bananas, causing significant economic losses by damaging the fruit. They also affect ornamental plants like Anthurium and Strelitzia. The primary damage occurs on the fruit, making it unmarketable, though still edible.

Key Points About Damage

1. Feeding Damage

• Thrips feed on the pseudostem and fruit of bananas.
• Feeding in leaf sheaths causes dark V-shaped marks on leaf petioles.
• Damaged tissue turns bronze or rust-colored with time.
• On fruits:
  • Young fruits show dark, smoky squiggles or curly feeding tracks.
  • Mature fruits develop oval-shaped reddish stains where fingers touch.
  • Extensive damage leads to reddish-brown or black discoloration and superficial cracks.

2. Life Cycle of Banana Rust Thrips

• Egg Stage:

  • Kidney-shaped eggs are laid inside plant tissue and hatch in 6-9 days.

• Nymph Stage:

  • First-stage nymphs are yellow, second-stage nymphs are yellow or orange.
  • They feed for about 8-10 days before migrating into the soil.

• Prepupa & Pupa Stage:

  • Prepupae develop wing pads and transition into pupae in 2-5 days.
  • Both stages remain in the soil or plant debris and do not feed.

• Adult Stage:

  • Adults emerge in 6-10 days and reinfest the plant.
  • Adult females are slender, creamy yellow to golden brown with dark eye-like spots on wings.

3. Environmental Preferences

• Temperature:

  • Thrips thrive in temperatures between 25–35°C.
  • Development slows below 20°C or above 40°C.

• Humidity:

  • Prefer humidity levels above 70%.
  • Dry conditions increase thrips’ susceptibility to stress and mortality.

Understanding the damage and life cycle of banana rust thrips is essential for effective management and reducing crop losses.

Image Source: TNAU,CABI