Several causes were mentioned as possibilities, the damage was obviously caused when the fruit were small:

• Lepidoptera (larvae of bagworms or Noctuidae (are there bagworms on the plant?)
• Coleoptera (some beetle adults)
• Orthoptera (grasshoppers)
• Tropical armyworm,
• Spodoptera litura – damage caused by very young caterpillars (has there been an armyworm/cutworm outbreak recently?)

Other questions are were:

• Is there any telltale frass in the bunches
• Was there any foliage damage on affected plants?
• Were the bracts also eaten? (This could give a clue to whether it was caused by a caterpillar, beetle or grasshopper as they have distinctly different frass.
• Are there slugs/snails that could be implicated, as these are known to cause similar damage.

Similar damage was reported on Cavendish bananas caused by Spodotera litura in Australia. Palau did not think it was mollusc damage.

Palau sent more photos of the same disorder in August 2003. Again, members were not sure of the cause, although scab moth (Nacoleia octasema) was mentioned, but the symptoms appeared to differ: they tend to be darker. It appears to be worse in poorly maintained plantings. The Banana flower thrip (Thrip hawaiiensis) was another suggestion.