National
Pest Alert
National
Pest Alert
Pink Hibiscus Mealybug
Maconellicoccus hirsutus (Green)
Origin and Distribution of Pink Hibiscus
Mealybug
The pink hibiscus mealybug (PHM), thought to be native to south -
ern Asia, is a serious pest of numerous host plants in many tropical
and subtropical climates. The distribution of PHM has subsequently
spread to Africa, Australia as well as areas within North, Central,
and South America. In the United States, PHM was first detected in
Hawaii in 1984, California in 1999, and Florida in 2002. Biological
control efforts have been successfully implemented for all of these
populations, which have shown significant impact on reducing
this mealybug’s population density. The Florida PHM population
continues to spread since its initial introduction followed by parasit -
oid releases being made in these newly infested locations. By 2005,
established populations of PHM have been detected in at least
eight primarily south Florida counties. Increased concerns over
the spread of PHM arose in 2004 due to the accidental shipment of
900,000 hibiscus plants potentially infested with PHM to 36 U.S.
states from a south Florida nursery. States that are considered cli -
matically suitable for pink hibiscus mealybug are Alabama, Arizona,
Arkansas, California, Florida, Georgia, Hawaii, Louisiana, Mis -
sissippi, Oklahoma, Nevada, New Mexico, North Carolina, South
Carolina, Tennessee, Texas, Utah, and Virginia based on comparing
climates of infested regions around the world.
Host Range
The broad host range of PHM allows for rapid spread of the insect
once introduced into an area, but the most commonly encountered
host plant material in Florida includes hibiscus, Florida trema, and
senna. PHM is know to infest more than 300 plant species. To view
an expanded list of hosts, please visit http://ncipmc.org/phmb/
index.cfm .
Description of PHM
Female adult PHM are approximately 3 mm in length (1/10 inches),
wingless, and have piercing–sucking mouthparts. A white cot -
ton-like wax covers the female’s reddish body. When punctured,
the female’s body fluids are also reddish, but it is important to note
that some other mealybug species may have a similar coloration.
PHM egg masses
are pinkish. Newly
emerged first instars
or crawlers are
pink. Nymphs of
both sexes resemble
smaller versions
of mature adult
females. The male
pupal stage is a
sessile cocoon made
of mealy wax. The
reddish brown adult
male PHM are
slightly smaller than
the female; has one
pair of wings; and
two long, waxy tails
(caudal filaments). Because the adult males have nonfunctioning
mouthparts and only live for a couple of days, the adult male is not
as commonly observed in the field around plant material.
Life Cycle
Adult female PHM has five life stages: egg, first instar (crawler),
second instar (nymph), third instar (nymph), and fourth instar
(adult). Adult male PHM has six life stages: egg, first instar (crawl -
er), second instar (nymph), third instar (prepupal), fourth instar
(pupal), and fifth instar (adult). Dispersal primarily occurs in the
crawler and nymphal stages through walking, wind, or hitchhiking
on animal or plant material. Unmated females produce a sex pher -
omone to attract males. After mating, females secrete an irregu -
lar-shaped white cotton-like egg mass that contains 300 to 600
eggs that turn pink as they mature. First instars (crawlers)
are pink and emerge from the eggs. In tropical climates,
PHM remains active year-round and may produce
up to 15 generations per year. In cooler climates,
PHM overwinters in the egg or adult female
stage in bark crevices, soil, tree holes,
fruit, and crumpled leaf clusters.
Pink hibiscus mealybug eggs.
Plant Symptoms and Monitoring
Heavy white, cotton-like, waxy buildup on branches and stems of
host plants may indicate PHM infestations. Female PHM injects
toxic saliva while feeding on fluids from many plant species, re -
sulting in leaf curling similar to damage caused by viruses. Heavily
infested plants are stunted, fruits may be deformed, and shoot tips
may develop a bushy appearance commonly referred to as “bunchy
top.” Black sooty mold may develop on infested plant leaves as a
result of PMH honeydew excretions. Extremely high populations of
PMH can kill plants.
If you suspect trees or plants are infested with PHM, contact your
state’s university diagnostic laboratory or Department of Agri -
culture diagnostic laboratory immediately (contact university
extension personnel for the address of the diagnostic laboratory).
Field identification is not definitive. Several other mealybugs may
resemble PHM in the field. PHM samples for all new state or county
records should be submitted for species-level confirmation. The
National Plant Diagnostic Network’s (NPDN) Standard Operating
Procedure (SOP) for PHM species-level confirmation is currently
available on the Southern Plant Diagnostic Network’s pest alert page
at http://spdn.ifas.ufl.edu/Pest_alert.html . The NPDN PHM SOP
will be updated periodically as needed.
Biological Control
The use of natural enemies has been shown to reduce PHM
populations. In California, Florida, and Hawaii the release of two
parasitic wasps, Anagyrus kamali Moursi and Gyranusoidea indica
Shafee, Alam & Agarwal (Hymenoptera: Entricidae) reduced and
maintained PHM populations below economically damaging levels.
The predaceous lady beetle Cryptolaemus montrouzieri Mulsant is
a voracious feeder on PHM and has been effectively used to control
limited PHM infestations alone, but adults are known to disperse
when PHM populations drop to low levels. This behavior allows
PHM to increase its population densities above levels that are
normally self-sustained by parasites alone. The larval stage of the
beetle may be mistaken for large mealybugs due to their heavy wax
coating, similar to PHM.
Management
Because PHM is a regulated organism, management, destruction,
and disposal protocols are coordinated by state regulatory officials.
If diagnosticians confirm PHM infestation of plants at nurseries or
other commercial landscape facilities, quarantine measures will be
implemented per state protocols. Due to a zero tolerance standard
for PHM in nursery stock, the destruction of infested plant material
and the application of prescribed chemicals may be recommended.
Homeowners should contact their local cooperative extension ser -
vice for questions about suspect PHM-infested plants. Each state’s
local cooperative extension service, state department of agriculture,
and APHIS-associated personnel will determine if a biological con -
trol release is appropriate.
For more information on PHM, please visit
ncipmc.org/action/alerts/phmb.php
March 2019
Editor: Julie Todd, Technically Correct Scientific Communications, State
College, PA.
Graphic designer: Gretchen Wieshuber, Studio 2D
Photos: courtesy of Lance Osborne, University of Florida
Reviewers: Amanda Hodges, University of Florida
Karolynne Griffiths, USDA–APHIS–PPQ
Dale Meyerdirk, USDA–APHIS–PPQ
Lance Osborne, University of Florida
1862 Land-Grant Universities
Auburn University University of Alaska University of Arizona University of
Arkansas University of California Colorado State University University of
Connecticut University of Delaware University of the District of Columbia
University of Florida University of Georgia University of Guam University
of Hawaii University of Idaho University of Illinois Purdue University Iowa
State University Kansas State University University of Kentucky Louisanna
State University University of Maine University of Maryland University of
Massachusetts Michigan State University University of Minnesota Mississip -
pi State University University of Missouri Montana State University Uni -
versity of Nebraska University of Nevada University of New Hampshire Rut -
gers New Mexico State University Cornell University North Carolina State
University North Dakota State University Ohio State University Oklahoma
State University Oregon State University Pennsylvania State University Uni -
versity of Puerto Rico University of Rhode Island Clemson University South
Dakota State University University of Tennessee Texas A&M University
Utah State University University of Vermont University of the Virgin Islands
Virginia Polytechnic Institute & State University Washington State Univer -
sity West Virginia University West Virginia State University University of
Wisconsin University of Wyoming
For information about the Pest Alert program, please contact Laura Iles, co-director of the North Central IPM Center, at ljesse@iastate.edu .
This work is supported by the Crop Protection and Pest Management Program (2014-70006-22486) from the USDA National Institute of Food and Agriculture.
(top left) Adult
female pink hibiscus
mealybugs. (top
right) Pink hibiscus
mealybug egg mass.
(left) Infestation of
pink hibiscus mealy -
bug on hibiscus
resulting in “bunchy
top” injury.
