Pink Hibiscus Mealybug
PHM

Information and photos: FDACS, Division of Plant Industry (DPI)

PHM Hosts (pdf)

PHM Fact Sheet (pdf)

Manatee County Detected in northwest Manatee County in September 2005 on hybrid hibiscus plants. By mid-December 2005, DPI inspector had released two species of beneficial, parasitic wasps (size of gnats): - 1,200 beneficial wasps released at three sites (approximately 3,600 thus far). - The wasps are having a visible, positive effect as seen in locally reduced infestations. PHM also observed on other ornamentals: impatiens, viburnums, wedelia and others. Control Insecticidal applications on infested plants: it is very important to use low residual products (e.g., horticultural oils and insecticidal soaps) that will not kill these parasitic wasps. They ARE working! Prune off heavily infested stems. Double bag for disposal in landfill. This sounds counterproductive, but…leave a small section of the plant unsprayed to provide a food source for these beneficial wasps. Be responsible— tarp vehicles to prevent dispersal along maintenance routes.

Florida Summary: FDACS Press Release

October 19, 2006

TINY WASPS PROVING HELPFUL TO AREA GARDENS IN CONTROLLING DESTRUCTIVE PINK HIBISCUS MEALYBUG

TALLAHASSEE -- Florida Agriculture Commissioner Charles H. Bronson today announced that biological control program efforts under way in more than 30 Florida counties are proving successful in controlling the destructive pink hibiscus mealybug (PHM). PHM was first discovered in the country in Broward County four years ago.

"Florida was ready for the discovery of PHM, recognizing that because of its prevalence in the Caribbean, it was only a matter of time before it arrived in the United States," Bronson said. "Florida is besieged with invasive plant pests and diseases because of our climate and location, and finding natural solutions to these problems is a key component of the Department's mission."

Fortunately, PHM has some natural enemies -- two are parasitic, gnat-sized wasps (Anagyrus kamali and Gyranusoidea indica) that attack PHM but cause no harm to other insects, plants or animals. Another enemy that is helping to control PHM numbers is a lady beetle (Cryptolaemus) that is a predator of PHM and already well established in Florida.

PHM has spread to 34 Florida counties, including Manatee, Sarasota, Pinellas and Hillsborough. Most of the infestations have been found on hibiscus plants. Biological control parasites are being released in all counties with current infestations. In the last four years, more than 2 million have been released.

In addition to PHM parasite-rearing facilities in California and Puerto Rico, the parasites are now being reared at the Department's Division of Plant Industry in Gainesville at a rate of 16,000 per week. Currently, two-thirds of these are being released in the Sarasota/Manatee county area where some of the state's newest infestations have been identified.

Even though the biological control program is helping to suppress the population of PHM, eradication is not feasible, and pest management is a more realistic approach. After the biological control parasites are released in an area, in time, usually two or three months, they will reproduce and spread out miles from the initial release site.

Biological control programs conducted in the Caribbean have reported 60-80 percent reduction of PHM within six months of parasite releases at test sites, and 95-98 percent after one year. The southeast Florida PHM biological control program has been ongoing since the initial outbreak in June 2002, and results have been promising. In Broward and Miami-Dade counties, plant recovery is excellent. Average decline in the PHM adult female population at study sites was 97.2 percent.

PHM occurs in most tropical areas of the world and attacks more than 200 plant species, including many found in Florida, such as hibiscus, citrus, mango, avocado, tomato, cucumbers and others. It is a tiny (3mm) sap-sucking insect that forms colonies on host plants, which, if left undisturbed, can grow into large cotton-like masses of white waxy deposits on branches and leaves. PHM feeds on the sap of the plant and releases toxic substances causing injury and sometimes death to the plant. PHM infestations are spread by wind, on infected plant material, also by ants or other small insects.

Although PHM is potentially a very serious threat, homeowners should not become overly concerned because Florida is home to more than 200 species of relatively harmless mealybugs, all of which share a similar appearance once they infest a host plant. Only an entomologist can determine if a plant has PHM. PHM can be distinguished from other mealybug species by its reddish-brown, smooth body and pink-to-red body fluid.

If homeowners think their plants may have PHM, they can call the state helpline at 1-888-397-1517. State plant inspectors will check properties in new areas suspected of having PHM. If PHM has already been detected in an area, and the beneficial parasites have been released, it may not be necessary to check individual yards. The Department is asking that homeowners and lawn maintenance companies control PHM damage to plants by cutting away damaged areas, double- bagging plant debris and disposing of it with their household garbage, not their yard trash. Yard trash is often composted and spread back into the environment. The state is also asking homeowners in areas where the PHM parasites are being released to avoid using pesticides on their landscape plants because the insecticides will kill the beneficial parasites that are being released to control PHM.

More information about the pink hibiscus mealybug is available on the Department's web site at http://www.doacs.state.fl.us/pi or call 1-888-397-1517.

                                                    Updated November 16, 2006