Tips For Controlling Whiteflies On Hibiscus Plants

Hibiscus plants make up a large genus of the Malvaceae family, consisting of hundreds of species of exotic-looking flowering plants. 

These plants are native to temperate and tropical climates and are best known for their big, showy blooms.

Colony of whiteflies that like to feed Hibiscus

Hibiscus plants are usually categorized as:

These plants grow in a variety of sizes with dark green foliage and long-lasting, trumpet-shaped flowers in shades of white, pink, yellow, peach, lavender and red. 

The petals sometimes have multiple colors.

Some common varieties of hibiscus plants include Flower of an hour, China Rose, Rock Hibiscus, Abelmosk, rosemallows, and Hawaiian hibiscus.

Hibiscus plants prefer a lot of sun exposure, but winter hardiness depends upon the variety. 

For instance, tropical hibiscus withstands winter season in USDA hardiness zones 10 through 12, whereas hardy perennials survive zones 4 to 9. 

In colder regions, they are often grown in containers as ornamental plants placed in patios during summer.

When grown with full sun, well-drained soil, and adequate water, these plants grow up to 15′ feet tall and the vibrant flowers can grow as big as 6” inches in diameter. 

These plants add exotic allure to a garden when grown singly in containers or as a part of the hedge.

The colorful appearance is particularly attractive to hummingbirds, butterflies, and numerous insects. 

Whiteflies, Aphids, and mealybugs are among the most common pests infesting these plants.

More on Other Hibiscus Pests:

Here’s a guide on how to get rid of the whiteflies on hibiscus plants.

What Are Whiteflies?

A notorious pest associated with the hibiscus plant is the “giant” whitefly. 

Known by its scientific name Trialeurodes vaporariorum, whiteflies are tiny, flying insects that are often found on the underside of leaves. 

As the name suggests, they are white or light-colored and survive by sucking the sap out of the leaves leaving behind sooty mold.

Simply giving a good shake to the infested plant would help you identify the presence of these pests. 

When disturbed, whiteflies take flight forming a thick cloud of flying insects and come back later to settle on the leaves again.

Whiteflies commonly infest outdoor hibiscus plants in southern and coastal areas, where they are present all year. 

However, in northern regions, these flies target the indoor plants grown in containers. 

They prefer to feed off a variety of ornamental and vegetable plants including hibiscus, potato, cucumber, grape, tomato, eggplant, okra, cabbage, citrus, and poinsettia.

Adult whiteflies are 1/16” inch long with powdery white wings and little antenna. 

They resemble moths and are found over the leaves and stem ends.

The life cycle of whiteflies begins with adult females lay eggs clusters of 200-400 eggs on the undersides of leaves of the plant. 

The eggs hatch within a week. 

Young nymphs are oval-shaped and have a scaly appearance. 

Once they pass the stage of the mealybugs, called crawlers, they become flattened and stick to the underside of the leaves and feed off the host plants.

They remain stationary during the rest of the nymphal stages. 

After the pupal stage, the nymphs transform into mature adults responsible to repeat the cycle. 

The lifespan of each adult is up to 2 months.

Whitefly Damage

Whiteflies, both nymphs, and adults damage the hibiscus plants by sucking the sap from the new plants, resulting in problems like stunted growth, inability to produce flowers, and yellow foliage.

These insects thrive on the plant’s nutrients and water, making it weak and prone to diseases. 

Whiteflies are the real culprits behind the transmission of various viral diseases as well.

An additional hazard is a secretion by white flies. 

These stubborn garden pests secrete honeydew, like aphids, which is a sugary, sticky, black residue. 

This sooty mold covers the leaves and interferes with the process of photosynthesis.

Whiteflies tarnish the appearance of an otherwise lovely hibiscus plant. 

The foliage becomes discolored or starts to fall.  

Extensive whitefly infestation can cause severe damage and become fatal for the hibiscus plant.

Whitefly Control

Once you have identified the houseplant pest infestation…

  • Inspect the leaf surfaces of the hibiscus plant and identify flattened whitefly eggs and stationary nymphs. 
  • Use a pair of clippers to prune the infected leaves. 
  • Dispose of them carefully in a bag.
  • To kill whiteflies, always start with a strong water blast with a spray hose. 
  • Do it once every week to scatter the pests. 
  • Once the population scatters, spray soapy water, insecticidal soap (recipe), neem oil, or horticultural oil over the plant, especially coat underside of the leaves. 
  • This will suffocate the nymphs and inhibit their growth. 
  • Chemical insecticides might not be as beneficial or as effective as whiteflies are resistant to most of them.
  • Trap whiteflies with yellow sticky traps made out of ¼” inch long plywood divided into 3” by 10” –inch pieces. 
  • Apply petroleum jelly and liquid dish detergent on the pieces after painting them bright yellow. 
  • Place the traps facing the infested hibiscus plant and disturb the foliage. 
  • The insects will fly and stick into the trap.

As a preventive measure to control whitefly population, provide the habitat for their natural predators like hummingbirds and some beneficial insects such as ladybugs, dragonflies, and damselflies.