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Are your Hibiscus Plants making you see red?

–>The pink hibiscus mealybug (PHM), Maconellicoccus hirsutus, is a soft scale that indiscriminately attacks numerous exotic and native ornamental plants, trees and vegetables Keyswide and on the mainland.The major food source is hibiscus plants of all colors not just pink hibiscus.

Pink Hibiscus Mealybug damage
http://monroe.ifas.ufl.edu/pdf/Hort/2007_News_Articles/Pink_Hibiscus_Mealybug_01.07.pdf

PHMs feed on the soft tissues of many plants sucking out the sap and injecting a toxin which causes the following damage symptoms:
 
·Crinkled/twisted leaves and shoots
·Bunched and unopened leaves
·Distorted/bushy shoots
·White fluffy masses on stems, buds, fruits and roots
·Honeydew which attracts ants and results in sooty mold
·Flowers which do not open but shrivel and die
·Small deformed fruit

Uncontrolled PHMs can stunt plant growth making hibiscus leaves look like waded up paper and if their population is very high they can kill plants.

Control Measures
If the population on a plant is small, the PHM
–>can be controlled by pruning the affected branches, placing them in a plastic bag and discarding the bag with household garbage.

Chemicals such as horticultural soaps and oils have yielded limited success in controlling PHMs due to the coverings on the females and eggs.
Biological controls are considered the safest and have the most success in combating the PHM. The Mealybug Destroyer, Cryptolaemus montrouzieri, feeds on all stages of the PHM. The destroyer larvae looks similar to the female adult PHM but is much larger, moves quickly and should not be destroyed.
Two parasitoid wasps, Anagyrus kamali and Gyranusoidea indicaare being released in Monroe County by the Horticultural Extension Agent and Master Gardeners, in yards where PHM are identified. The tiny wasps DO NOT ATTACK plants, your pets or children; only PHMs. The wasps lay their eggs inside individual mealybugs. When the egg hatches it feeds on the mealybug and in 2-3 weeks it emerges as an adult leaving an empty shell “mummy” of a PHM behind. The adult wasps find mates and repeat the cycle.
If you think you have PHMs bring or send samples to your County Extension Agent and if PHMs are verified you may become the proud owner of your own parasitoid wasp family.
 
For more information:

http://mrec.ifas.ufl.edu/LSO/PinkMealybug.htm

http://www.freshfromflorida.com/pi/pest-alerts/maconellicoccus-hirsutus.html

http://trec.ifas.ufl.edu/mannion/pests.shtml

http://edis.ifas.ufl.edu/IN156

These links were current as of May, 2013.

Photo credits:
Dale Meyerdirk, APHIS
Kim Gabel, UF/IFAS
Lance Osborne, UF/IFAS

Article written by:
Monroe County Master Gardener Susan Matthews
Kim Gabel, UF/IFAS Monroe County Horticulture Extension Agent

One Comment on “Are your Hibiscus Plants making you see red?

  1. Regarding the Hibiscus Mealybug…I just recently moved back to SW Fl from out of state and purchased an older home with mature landscaping. There are several hibiscus and one was under severe attack from mealy bugs. I’m an organic gardener, so I wasnt interested in pesticides. I checked out the horticultural oils, but decided to try EMs (effective microorganisms). I didnt know if it would work, but I’m happy to report that one month later, I have lots of new growth and beautiful blooms. The mealybugs and the resulting damage (sooty, stumped branches,etc) are gone. I was pleasantly surprised, and continue to be amazed with EMs. I have no affiliation with the non profit company that makes EMs–EM America, but stumbled upon the product a couple years ago. It hasnt let me down yet. give it a try.