Sally Scalera

Brevard County Horticulture Extension Agent
3695 Lake Drive -- Cocoa FL 32926 -- 321-633-1702

Pink Hibiscus mealybug problems spreading

I originally wrote about the Pink Hibiscus mealybug (PHM) in June of 2003 because it had entered Florida. Now, though, we know it is in Brevard County. This fall it was found in a few neighborhoods in the Viera and Suntree area. Since it’s initial discovery it has also been found in Rockledge. The concern is that some of the yards that have the PHM are cared for by landscapers who could have accidentally spread it to other yards of some of their other customers. In an effort to try and discover all of the places the PHM may be and to keep it from becoming established in Brevard County and the state of Florida it is time to talk about the Pink Hibiscus Mealybug again.

The pink hibiscus mealybug, Maconellicoccus hirsutus, is a serious pest of many plants in tropical and subtropical regions. It was first discovered in Broward County in June 2002. There are areas of Broward County that are quarantined to try and stop the spread and establishment of this pest in Florida. If this mealybug does become established in Florida, the pink hibiscus mealybug is expected to attack many Florida crops including citrus, avocado, carmabola, fig, guava, mango, soursop and sugarcane; vegetable crops including asparagus, beans, beets, cabbage, peanuts, pigeon pea, cucumber, lettuce, pepper, pumpkin and tomato; forest trees and many species of ornamental plants including hibiscus, Allamanda, Angelica, Anthurium, Bouganvillea, Croton, ginger lily, Heliconia, Ixora, palms and oleanders.

The pink hibiscus mealybug is not just an agricultural problem. This pest will attack ornamental plants in yards and parks. It feeds on the soft tissue of many plant species and injects a toxic saliva that causes curling and contortion of the leaves. The entire plant may be stunted and the shoot tips develop a bushy appearance. Buds may not flower and the stems may twist. Fruit may also be deformed. The mealybug excretes honeydew which encourages the development of black sooty mold. Very high mealybug populations can kill plants!

The level of feeding damage depends on the vigor of the infested plant. Seedling trees and weakened trees are more susceptible. Shoots become twisted with shortened internodes, forming bunchy heads of small bushy leaves at the tips (“bunchy top”.) The curled leaves can resemble viral damage, but this pest is not known to vector any diseases (I guess we can be happy about that point!) Heavy infestations on young plants by the pink hibiscus mealybug may stunt their growth. The mealybug is found on stems, leaves, buds, fruit and roots of many plants. On hibiscus, the mealybug usually infests young twigs, causing deformed terminal growth due to the shortening of the internodes, deformed leaves and thickened twigs.

Adult mealybugs are small (about 3 mm long) and pink in body color but covered with a waxy secretion. The waxy filaments are short and females are usually obscured by this white mealy wax. When adults are crushed their body fluids are also pink. Females die shortly after depositing eggs. Freshly-laid eggs are orange, becoming pink before they hatch. Eggs are found in egg sacs. The first instar nymphs (crawlers) of the pink hibiscus mealybug disperse by walking or by wind. Nymphs also can walk considerable distances to find suitable host plants. The life cycle takes about 23-30 days.

This mealybug has a high reproductive rate (females can deposit up to 600 eggs) and produces up to 15 generations per year, so pest populations can become very large. Pink hibiscus mealybug eggs over winter in bark crevices, leaf scars, under bark, in the soil, tree boles, inside fruit clusters and inside crumpled leaf clusters.

As a review, here is what to look for:

• Crinkled or twisted leaves and shoots.
• Bunched and unopened leaves.
• Distorted or bushy shoots.
• White fluffy mass on buds, stems, fruits and roots.
• Unopened flowers which often shrivel and die.
• Small deformed fruits.

If you suspect that you have the Pink Hibiscus Mealybug then call the Division of Plant Industries hotline at (888) 397-1517 and please do not do any of the following:

• Trim the infested portions and place it out at the curb for yard trash pickup.
• Throw out an infested plant that may have the PHM and put it at the curb for yard trash pickup.
• For landscapers – do not carry suspected plant material in the back of your vehicles as you move about the county.

For all homeowners who employ a landscaper, please show them this article just in case they didn’t see it!

For more information on this pest you can You can go to the following website and then click on MEALYBUGS. From that page just click on the link to the Pink Hibiscus Mealybug page. The main website also has links to other agencies such as the Division of Plant Industries so you can find out all about the PHM and other newly arrived pests to the sunny state of Florida.