What causes bell peppers to rot while still hanging on the plant?
There are a number of fungal diseases that will cause fruit rot. In many cases, however, the rot is secondary to an insect that may either feed on the fruit or lay eggs. The tiny wounds made in this manner create an opening for the fungus or bacteria to enter.
Photo by Paul Choate, Univ. Florida
In the case of peppers, the pest is probably the pepper weevil. They make holes in the young pepper fruit and in the flower buds by the feeding of adult weevils, or egg laying of females. Then the weevils develop inside the fruit and as adults, burrow their way out.
Infested fruit that does not rot will have a blackened core and seeds as a result of larval feeding. Mature peppers are not susceptible to weevil attack, because the skin is usually too hard. In order to lay her eggs, a female first punctures the fruit or the bud with her mandibles (mouth parts), then inserts an egg into this hole and seals it with a clear yellow fluid which hardens.
Sanitation is very important in controlling this pest. Remove all peppers that have dropped to the ground. If weevil numbers build up and are causing major damage to the crop, there are registered pesticides available.
