A very common and beautiful flowering bush here in Central Florida is the hibiscus.
This can include the tropical hibiscus Hibiscus rosa-senensis, or a species of hardy hibiscus. Whichever type or variety you choose, the reason why we have them is for their beautiful blooms. Hibiscus can be a fussy plant, dropping its buds because of too much or too little irrigation, or because it is unhappy with the temperatures. But now we have two very tiny insects that can cause those flower buds to drop and causing confusion.
One insect pest that causes bud drop on hibiscus is the larval stage of the hibiscus bud midge.
This fly lays its eggs into the open tips of young flower buds, the larvae feed on the inside of the bud and cause it to drop off prematurely. They become very tiny adult flies, about the size of a gnat, and only live for four days. This pest has been here in Florida for many years and is occasionally a pest of vegetables and other flowering landscape ornamentals.
A new pest of Florida hibiscus plants is the hibiscus bud weevil.
This beetle was discovered in Hernando County this past May and has already become a problem for nurseries and homeowners alike. The adults lay their eggs on the buds and the developing larvae feed on the pollen inside of the flowers. This feeding results in flower bud drop.
There are no reliable homeowner available chemical controls for these pests, but good sanitation can help. Pick up and dispose of all fallen blooms and if you suspect your hibiscus blooms are falling off because of an insect problem, feel free to bring them by our office for a definite diagnosis.
For more information about insect pests in your landscape or home, stop by or call UF/IFAS Extension Hernando County weekdays from 8 to 5. Our office is in the airport industrial park at 16110 Aviation Loop Drive, Brooksville, 34604; (352) 754-4433. In addition, Master Gardeners are available to assist you at the Master Gardener nursery from 9AM to noon every Wednesday and Saturday (weather permitting). Our nursery is located behind the Hernando County fairgrounds at 19490 Oliver Street, Brooksville.