| October 2008. Tomatoes on a commercial farm in Pohnpie, Federated States of Micronesia, have a very high fruit damage, something like 50% of the fruits are showing round soft areas with a small pin hole in the centre. It was thfought to be fruit piercing moth damage. The frmer was told to cover the plot with an insect screen and check at night time to see if he can find the moths. Any comments?
Fruit piercing moth is one possibility, but sap-sucking bugs, for instance Nezara, is another. If it were fruit fly damage, it woudl be expected that larvae would be found inside the fruit. It appears as if the skin is firm around the ‘pinhole’. Green vegetable bugs produce this type of damage to tomatoes in north Queensland. The area adjacent to the feeding puncture tends not to colour up (as in the photo) and not break down (rot), compared to the collapse associated with fruit fly damage. These bugs feed on the smaller fruit while they are still green and can be difficult to spot as they move to the opposite side of the fruit when monitoring or to the spaces between a fruit cluster. Shake the bushes with a tray underneath and these bugs will drop off and can be collected before they take flight, or spray the plants with a knockdown insecticide (one of the synthetic pyrethroids) to reveal the culprit.
The total collapse of fruit attacked by fruit pierccing moths is a result of the introduction of rot-causing organisms, such as bacteria and fungi . In other fruit, such as lychee, carambola and citrus fruit, collapse/deterioration occurs rapidly and a fruit as soft as a tomato would break down very quickly too.
It was also pointed out that the fruit damaged by Nizara typically shows “multiple punctures” on the skin (see lower photo). |
