My Florida Tropical Garden

Are your hibiscus buds dropping off prematurely? Hibiscus bud drop is a sign that something is wrong. In some cases, it's the hibiscus gall midge. The gall midge is a small fly thats lays its eggs inside flower buds. As the larvae hatches from the egg, it feeds inside the flower bud until it drops to the ground. Once on the ground, the larvae exit the flower bud and enter the soil to pupate. After a couple weeks, an adult gall midge emerges from the soil and the whole cycle starts again.

If you suspect gall midges, it's relatively easy to identify. Look for yellowing flower buds and pick one off the plant for inspection. Carefully open the flower bud and look for tiny worm-like larvae inside. Another trick is to pickup any dropped flower buds and put them in a sealed ziplock bag. After a couple hours, check the sealed bag for small larvae that have exited the buds.

Most spray pesticides are ineffective as they don't come in contact with the larvae. The key to controlling this pest is to treat the plant with a systemic pesticide to kill larvae inside the flower buds and treating the soil around the plant to kill off any larvae that have entered the soil. For a systemic pesticide, I sprayed Bayer 3-in-1 (active ingredient: imidacloprid) on the plant. For soil treatment, I sprinkled Bayer Complete Insect Killer granules. On top of this, I made sure to pick up any dropped flower buds and put them in a sealed ziplock bag so the larvae could not escape into the soil. Be persistant to catch dropped buds to ensure your capturing the larvae. After a week or two, the flower buds will stop falling off and your plant will be midge free.