Tomato fruit rot

On one of our commercial vegetable farms I observed a very high fruit damage something like 50% of the fruits were showing the round soft areas with a small pin hole in the center. My best guess is fruit piercing moth damage. I told the farmer to cover the plot with an insect screen and check at night time if he can find fruit piercing moths. Do we have any comments or disagreement to my ID… Mark

RESPONSE:

From Peter: One of the likely culprits. Other possibilities are a sap-sucking bug like Nezara – sucking the fruits when slightly smaller – and, hopefully not, fruit fly – in which case there would be larvae inside.

From Richard: Is there any evidence of eggs and or larvae in the pulp? If not, then it is more likely to be an insect feeding than an insect ovipositing.

It appears as if the skin is firm around the ‘pinhole’. Green vegetable bugs, (as mentioned by Peter Maddison in his reply), and another smaller green bug produce this type of damage to tomatoes in my home garden in north Queensland. The area adjacent to the feeding puncture tends not to colour up (as in your 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.  If you shake the bushes with a tray underneath these bugs will drop off and can be collected before they take flight. If you can spray the plants with a knockdown insecticide (one of the synthetic pyrethroids) this might also reveal the culprit.

I am unfamiliar with FPM damage to tomato but would have thought if this was caused by FPM that there would have been collapse of the adjacent area. This collapse probably occurs as a result of the introduction of rot 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.

Anyway hope these comments help but good observation by he grower as you suggest should identify the culprit. I will be very interested to hear what you find out in due course is causing this problem.

From Konrad: Thank you for your reply and the information. I don’t think the damage is caused by fruit flies because there were no eggs or larvae in the fruits. However I did see Green Vegetable bugs and Leaf Footed Plant Bugs. It is possible that the damage is caused by Nezara. I should go back to the field at night (it’s a 25 km drive) and see if their are FPM’s. Later the fruit does break down and rots.

From Tolo Iosefa: It is fruit piercing moth damage, best way to be sure of this is visit your garden early hours of the evening (night) with a net and a light and see if any FPM fly around your tomatoes.

From Dick: Agree with FPM. Go at dusk with a torch and a plastic bag and catch them. Three nights will probably be enough.