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common name: lobate lac scale
scientific name: Paratachardina pseudolobata (=lobata) Kondo & Gullan (Hemiptera: Sternorrhyncha: Coccoidea: Kerriidae)

Introduction - Description and Biology - The Lac Scale Family - Effects on Host Plants - Host Range - Potential Expansion in Distribution - Pest Management Prospects - Selected References - Versión en Español

Introduction (Back to Top)

The lobate lac scale, Paratachardina pseudolobata Kondo & Gullan (Hemiptera: Sternorrhyncha: Coccoidea: Kerriidae), was found for the first time in Florida on a hibiscus (Hibiscus rosa-sinensis) in the town of Davie (Broward County) in August 1999 by personnel of the Florida Department of Agriculture and Consumer Services, Division of Plant Industry (DPI) (Hamon 2001). The identification of the species as P. lobata by Avas Hamon of DPI was confirmed by D. R. Miller of the Systematic Entomology Laboratory, U. S. Department of Agriculture, Beltsville, MD. Previously, in 1992, Dr. Hamon (personal communication) had identified this species from specimens sent to him from the Bahamas.

Mature females of lobate lac scale, Paratachardina pseudolobata Kondo & Gullan.

Figure 1. Mature females of lobate lac scale, Paratachardina pseudolobata Kondo & Gullan. Photograph by F. W. Howard, University of Florida.

Paratachardina lobata is considered native to Southern Asia and was previously known as an adventive on Christmas Island (Australia). However, in 2007 Kondo and PJ Gullan published a review of the genus Paratachardina in which they determined on the basis of minute morphological features and molecular analysis that the lobate lac scale occurring in Florida, Bahamas, and Christmas Island is a new species, which they named P. pseudolobata.

Although DPI personnel made considerable effort, locating and destroying infested host plants, by 2002 lobate lac scale was distributed from southern Miami-Dade to Palm Beach County. At present (2008) it is distributed in virtually all counties of southern Florida.

Description and Biology (Back to Top)

The mature females of P. pseudolabata are about 1.5-2 mm long, and about the same width. The body has two pairs of prominent lobes. To the practiced eye, this scale insect's x-shaped appearance is discernable, even without magnification. The testa is extremely hard and brittle, glossy and of a dark reddish brown color, but often appears dull and black due to a coating of sooty-mold. The first instars (crawlers) are elongate-oval, deep red, and about 0.4 mm long. The characteristic lobate pattern develops in the second instar. The second instar female presumably molts to the adult female as in otherscale insects. Males of this species have not been observed in Florida.

 

First instar (crawler) of lobate lac scale, Paratachardina pseudolobata Kondo & Gullan.

Figure 2. First instar (crawler) of lobate lac scale, Paratachardina pseudolobata Kondo & Gullan. Photograph by F. W. Howard, University of Florida.

Since the mature females of scale insects are wingless, they play no role in dispersal of populations to occupy new host plants. Scale insects rely mostly on passive dispersal of the crawler stage via air currents. Phoresis (being carried by birds and other animals) may be of some importance in some species. Undoubtedly, movement of infested host plants from one locality to the next is a key factor in spreading scale insect pests in urban areas.

The Lac Scale Family (Back to Top)

The species belongs to the lac scale family, Kerriidae, the best-known species of which is the true lac scale insect, Kerria lacca lacca (Kerr). The testa of the true lac scale insect has been utilized for centuries for making shellac and similar products. However, most species of the family, including P. pseudolabata, do not produce any material of known commercial value. The specific scientific name, pseudolabata, refers to the four prominent projections, or lobes, of this scale, and the vernacular name 'lobate lac scale' may be used for this species.

Of the 28 families of Coccoidea recognized by Miller and Ben-Dov (2002), 11 are represented by species native to Florida (Aclerdidae, Asterolecaniidae, Diaspididae, Cerococcidae, Coccidae, Conchaspidae, Eriococcidae, Kermesidae, Margarodidae, Ortheziidae, and Pseucococcidae). No species of Kerriidae is native to Florida and adjacent land areas. The Kerriidae is confined mostly to the tropics, with a minority of species found in low latitude desert areas. Of the 87 described species, 64 are distributed in the eastern hemisphere. Of the species native to the western hemisphere, 13 are reported from South America, six from Mexico (two of which are also reported in the southwestern U.S.), three reported only in the southwestern U.S., and one from Jamaica (Ben-Dove 2002).

Effects on Host Plants (Back to Top)

Paratachardina pseudolobata has been found mostly on woody dicotyledonous plants. It infests the woody portions of twigs and small branches and less frequently main stems of usually < 2 cm in diameter, but usually not branches or main stems of > 2 cm in diameter. It has not been observed on foliage.

Wax-myrtle branch infested with lobate lac scale, Paratachardina pseudolobata Kondo & Gullan.

Figure 3. Wax-myrtle branch infested with lobate lac scale, Paratachardina pseudolobata Kondo & Gullan. Photograph by F. W. Howard, University of Florida.

On highly susceptible hosts, the scale insects are crowded, forming a contiguous mass that appears as a dark, lumpy crust. On wax-myrtle (Myrica cerifera), a highly susceptible host, up to 42 mature females have been counted per 1 cm segment of twig. Sooty mold covers the branches, the insects themselves, and occurs in patches on the foliage. Dense infestations are associated with branch dieback of some plant species, and in severe cases, highly infested shrubs and small trees have died. Wax-myrtle is especially prone to become heavily infested and die from the effects of lobate lac scale. Some plant species appear to tolerate dense infestations, but this may be illusory, as the long-term effects of such infestations are not yet known.

Sooty mold on mango leaves, an indirect result of infestation by lobate lac scale, Paratachardina pseudolobata Kondo & Gullan.

Figure 4. Sooty mold on mango leaves, an indirect result of infestation by lobate lac scale, Paratachardina pseudolobata Kondo & Gullan. Photograph by F. W. Howard, University of Florida.

Wax-myrtles in the wild (left) and as a hedge (right) killed by infestations of lobate lac scale, Paratachardina pseudolobata Kondo & Gullan.

Figure 5. Wax-myrtles in the wild (left) and as a hedge (right) killed by infestations of lobate lac scale, Paratachardina pseudolobata Kondo & Gullan. Photograph by F. W. Howard, University of Florida.

Host Range (Back to Top)

This scale insect is primarily a pest of woody dicotyledonous plants. There are rare records of lobate lac scale on other kinds of plants, including one on a coniferous species, viz. southern red cedar, Juniperus silicicola, and on a palm, Phoenix roebelenii. As of June 2006, 307 species of woody plants had been determined to be hosts of P. pseudolobata in Florida (Howard et al. 2006), including 83 plant species native to Florida. Most of the exotic host plants are grown as ornamental shrubs or trees, or as fruit trees. Some of these are extremely important in the urban landscape as shade trees, specimen trees, or hedges. Some plant families, notably Fabaceae, Myrtacea, and Moraceae are especially well represented by species that serve as hosts, but this may be related to their abundance in the landscape or other sources of bias

Plants at different sites have been exposed to infestations for different periods and infestation levels are highly variable. Differences in susceptibility have not been determined experimentally. However, certain species appear to be highly susceptible, including certain natives, e.g., wax-myrtle, cocoplum (Chrysobalanus icaco), buttonwood (Conocarpus erectus), strangler-fig (Ficus aurea), myrsine (Myrsine guianensis), red bay (Persea borbonia), and wild-coffee (Psychotria nervosa); popular exotic ornamental plants, e.g., black-olive (Bucida buceras), Indian laurel (Ficus microcarpa), Benjamin fig (F. benjamina); and fruit trees, e.g., lychee (Litchi chinensis), mango (Mangifera indica), and star-fruit (Averrhoa carambola).

Twig of mango infested with lobate lac scale, Paratachardina pseudolobata Kondo & Gullan.

Figure 6. Twig of mango infested with lobate lac scale, Paratachardina pseudolobata Kondo & Gullan. Photograph by F. W. Howard, University of Florida.

Table 1. Host list of lobate lac scale in southern Florida

(from Howard et al. 2006).
(* indicates species native to Florida)

Angiosperms: dicotyledons

Acanthaceae
Graptophyllum pictum (L.)
Justicia brandegeana Wasshausen & L. B. Smith
Pachystachys lutea Nees
Ruellia brittoniana E. Leonard

Aceraceae
*Acer rubrum L.

Anacardiaceae
Mangifera indica L.
Metopium toxiferum (L.) Krug & Urban
Pseudospondias microcarpa (A. Richard) Engler
Rhus copallinum L.
Schinus molle L.
Schinus terebinthifolius Raddi
Spondias mombin L.
Toxicodendron radicans (L.) Kuntze

Annonaceae
Annona cherimola Miller X A. squamosa L.
*Annona glabra L.
Annona muricata L.
Annona reticulata L.
Annona squamosa L.
Cananga odorata (Lamarck ) J. D. Hooker & T. Thomson

Aquifoliaceae
Ilex cassine L.
*Ilex vomitoria Aiton

Araliaceae
Schefflera actinophylla (Endlicher) Harms
Schefflera elegantissima (Veitch ex Masters) Lowry & Frodin

Asteraceae
Ambrosia artemisiifolia L.
*Baccharis halimifolia L.
Bidens alba (L.) de Candolle
Flaveria linearis Lagasca
Montanoa grandiflora Alaman ex de Candolle
Pluchea carolinensis (Jacquin) G. Don
Tridax procumbens L.
Verbesina virginica L.

Begoniaceae
Begonia sp.

Bignoniaceae
Amphitecna latifolia (Miller) A. Gentry
Dolichandrone spathacea (L. f.) Schumann
Tecoma stans (L.) Humboldt, Bolpland and Kunth
Tecoma capensis (Thunberg) Spach

Burseraceae
*Bursera simaruba (L.) Sargent

Capparaceae
*Capparis cynophallophora L.

Caprifoliaceae
Viburnum sp.

Casuarinaceae
Casuarina cunninghamiana Miguel
Casuarina equisetifolia L.

Celtidaceae
*Celtis laevigata Willdenow
*Trema micranthum (L.) Blume

Chrysobalanaceae
*Chrysobalanus icaco L.
Licania tomentosa (Bentham) Fritsch

Clusiaceae
Calophylum brasiliense Cambessédes
Calophyllum calaba L.
Calophyllum inophyllum L.
Clusia lanceolata Cambessèdes
*Clusia rosea Jacquin
Garcinia mestonii F.M.Bailey
Garcinia prainiana King
Mesua ferrea L.
Rheedia acuminata (Ruiz & Pavon) Planchon & Triana
Rheedia aristata Grisebach
Rheedia sp.
Rheedia edulis (Seemann) Triana et Planchon
Rheedia macrophylla Planchon & Triana

Combretaceae
Bucida (B.spinosa x buceras)
Bucida buceras L.
Combretum aubletii de Candolle
Combretum obovatum F. Hoffmann
*Conocarpus erectus L.
Laguncularia racemosa (L.) Gaertner f.
Terminalia muelleri Bentham
Terminalia catappa L.

Ebenaceae
Diospyros digyna Jacquin
Diospyros mespiliformis Hochstetter

Elaeocarpaceae
Elaeocarpus decipiens Hemsley

Erythoxylaceae
Erythoxylum reticulatum

Euphorbiaceae
Acalypha godseffiana Sander ex Mast
Acalypha hispida Burman f.
Acalypha wilkesiana J. Mueller
Antidesma bunius (L.) K. Sprengel
Antidesma dallachyanum Baillon
Antidesma platyphyllum Hame
Bridelia monoica (L.) Merrill
Chamaesyce hirta L.
Euphorbia leucocephala Lotsy
Flueggea acidoton (L.) G. L. Webster
Jatropha integerrima Jacquin
Mallotus philippinensis (Lamarck) Mueller Argoviensis

Fabaceae
Acacia auriculiformis Bentham
Acacia choriophylla Bentham
Acacia farnesiana (L.) Willdenow
Albizia lebbek (L.) Bentham
Amorpha herbacea (Walt.) var crenulata (Rydb.)Isely
Archidendron lucyi F. v. Mueller
Bauhinia sp.
Brya ebenus (L.) de Candolle
Butea monosperma (Lamarck) Taubert
Caesalpinia pulcherrima (L.) Swartz
Caesalpinia violacea (Miller) Standley
Cajanus cajan (L.) Huth
Calliandra emarginata (Humboldt & Bonpland) Bentham
Calliandra haematocephala Hasskarl
Calliandra surinamensis Bentham
Dalbergia ecastaphylum (L.) Taubert
Dalbergia sissoo de Candolle
Dalea carthagenensis (Jacq.) J.F. Macbride
Gigasiphon macrosiphon (Harms) Brenan
Inga affinis de Candolle
Inga edulis (Martius)
Leucaena leucocephala (Lamarck) de Wit
Lonchocarpus sp.
*Lysiloma latisiliqua (L.) Bentham
Lysiloma sabicu Bentham
Parmentiera aculeata (Kunth) Seemann
Peltophorum pterocarpum (de Candolle) K. Heyne
Pithecellobium flexicaule (Bentham) J.M. Coulter
Pithecellobium keyense ex Britton & Rose
Pongamia pinnata (L.) Pierre
Pseudosamanea cubana Britton & Rose (Barneby & Grimes)
Samanea saman (Jacquin) Merrill
Wallaceodendron celebicum Koorders

Fagaceae
*Quercus geminata Small
Quercus hemiphaerica Bartram Ex Willdenow
Quercus incana W. Bartram
*Quercus laurifolia Michaux
*Quercus virginiana Miller

Flacourtiaceae
Banara vanderbiltii Urban
Casearia arguta Humboldt, Bonpland & Kunth
Dovyalis hebecarpa (G. Gardner) Warburg

Lamiaceae
Leonotis leonurus (L.) R. Brown
Leonotis nepetifolia (L.) R. Brown
Ocimum sp.
Rosmarinus officinalis L.
Salvia coccinea P.J. Buchoz ex Etlinger
Solenostemon scutellarioides (L.) Codd

Lauraceae
Cinnamomum zeylanicum Blume
Laurus nobilis L.
*Licaria triandra (Swartz) Kostermans
Ocotea coriacea (Swartz) Britton (Lauraceae)
Persea americana Miller
*Persea borbonia (L.) Sprengel
Persea palustris (Rafinesque-Schmaltz) Sargent

Lecythidaceae
Lecythis minor Jacquin

Lythraceae
Ginoria glabra Grisebach
Ginoria nudiflora (Hemsley) Koehne
Lagerstroemia indica L.
Lagerstroemia speciosa (L.) Persoon (Lythraceae)
Lawsonia inermis L.

Magnoliaceae
Magnolia virginiana L.
Michelia champaca L.

Malvaceae
Abutilon sp.
Durio testudinarium
Heritiera littoralis Dryander
Hibiscus rosa-sinensis L.
Hibiscus schizopetalus (Masters) Hooker f.
Hibicus tiliaceus L.
Malvaviscus penduliflorus de Candolle
Pavonia bahamensis Hitchcock
Pavonia paludicola D. H. Nicolson
Ruizia cordata Cavanilles
Trichospermum mexicanum (de Candolle) Baillon
Urena lobata L.

Melastomataceae
Tetrazygia bicolor (Miller) Cogniaux

Meliaceae
Lansium domesticum Corrêa da Serra

Moraceae
Brosimum alicastrum Swartz
Ficus aspera G. Forster
*Ficus aurea Nuttall
Ficus benjamina L.
Ficus capensis Thunberg
Ficus citrifolia Miller
Ficus deltoidea Jack
Ficus elastica L.
Ficus microcarpa L. f.
Ficus natalensis Hochstetter
Ficus nota (Blanco) Merrill
Ficus pertusa L.
Ficus pumila L.
Ficus racemosa L.
Ficus rubiginosa Desfontaines ex Ventenat
Ficus rumphii Blume
Ficus salicifolia (Vahl) Berg
Ficus subcordata Blume
Ficus virens Aiton

Myricaceae
*Myrica cerifera L.

Myrsinaceae
*Ardisia escallonioides Chamisso & Schlechtendal
Ardisia hirtella
Ardisia revoluta Humbolt, Bonfland & Kunth
Ardisia sieboldii Miquel
Rapanea punctata (Lamarck) Lundell

Myrtaceae
Callistemon viminalis (Gaertner) Cheel
*Calyptranthes pallens Grisebach
Calyptranthes thomasiana O. Berg
*Calyptranthes zuzygium (L.) Swartz
Eucalyptus bella K. D. Hill & L. A. S. Johnson
*Eugenia axillaris (Swartz) Willdenow
Eugenia brasiliensis Lamarck
*Eugenia confusa de Candolle
Eugenia foetida Persoon
Eugenia luschnathiana Klotzsch ex O. Berg
Eugenia uniflora L.
Marliera edulis Cambessedes
Melaleuca bracteata F. Mueller
Melaleuca decora (Salisbury) Britten
Melaleuca quinquenervia (Cavanilles) S.T. Blake
Mosiera longipes (O. Berg) Small
Myrcianthes fragrans
Myrciaria cauliflora (de Candolle) O. Berg in Martius
Myrciaria vexator McVaugh
Pimenta dioica (L.) Merrill
Pimenta racemosa (Miller) J. W. Moore
Psidium androsianum (Urban) Correll
Psidium guajava L.
Psidium littorale Raddi
Syzigium cuminii (L.) Skeels
Syzygium grande (Wight) Walpers
Syzygium jambos (L.) Alston
Syzygium malaccense (L.) Merrill & Perry
Syzygium paniculatum Gaertner
Syzygium samarangense (Blume) Merrill & Perry

Onagraceae
Ludwigia peruviana (L.) Hara

Orchidaceae
Dendrobium aphyllum (Roxb.) C.E.C. Fischer

Oxalidaceae
Averrhoa bilimbi L.
Averrhoa carambola L.

Piperaceae
Piper sp.

Polygalaceae
Polygala cowellii (Britton) Blake

Polygonaceae
Antipogon leptopus Hooker & Arnott
Triplaris cumingiana Fischer & C.A. Meyer ex C.A. Meyer

Proteaceae
Macadamia integrifolia Maiden & Betche
Macadamia tetraphylla L. A. S. Johnson

Rhamnaceae
*Krugiodendron ferreum (Vahl) Urban
Ziziphus mauritiana Lamarck

Rhizophoraceae
Rhizophora mangle (L.)

Roseaceae
Malus sylvestris Miller
Pyrus sp.
Rosa sp.

Rubiaceae
Erithalis fruticosa L.
Gardenia jasminoides Ellis
Gardenia thunbergia L.f.
Hamelia cuprea Grisebach
*Hamelia patens Jacquin
Ixora sp.
Mussaenda erythrophylla Schumacher & Thonning
Pentas lanceolata (Forsskal) Deflers
*Psychotria ligustrifolia (Northrup) Millspaugh
*Psychotria nervosa Swartz
Psychotria punctata Vatke
Psychotria sulzneri Small
Psychotria viridis
Randia aculeata L.
Rondeletia leucophylla Kunth
Spermacoce verticillata L.

Rutaceae
Amyris balsamifera L.
Amyris elemifera L.
Citrus X paradisi Macfadyen
Clausena lansium (Loureiro) Skeels
Evodia ridleyi Hochreutiner
Fortunella japonica (Thunberg) Swingle
Murraya paniculata (L.) Jack

Salicaceae
*Salix caroliniana Michaux

Sapindaceae
Alectryon coriaceus Radlkofer
Allophylus cominia (L.) Swartz
Blighia sapida Konig
Cupaniopsis anacardioides (A. Richard) Radlkofer
Dodonaea viscosa Jacquin
*Exothea paniculata (Jussieu) Radlkofer
Filicium decipiens (Wight & Arnott) Thwaites
Harpullia arborea (Blanco) Radlkofer
Hypelate trifoliata Swartz
Koelreuteria elegans (Seemann) A.C. Smith
Litchi chinensis Sonnerat
Melicocca bijuga L.
Talisia olivaeformis (Humbolt, Bopland & Kunth) Radlkofer

Sapotaceae
*Bumelia celastrina Humboldt, Bonpland & Kunth
Calvaria inermis
Chrysophyllum cainito L.
*Chrysophyllum oliviforme L.
*Dipholis salicifolia (L.) Alphonse de Candolle
*Manilkara jaimiqui (C. Wright) Dubard
Manilkara kauki (L.) Dubard
Manilkara pleeana (Pierre) Cronquist
Manilkara roxburghiana (Wight) Dubard
Manilkara zapota (L.) Van Royen
Mimusops balata (Aublet) Gaertner
Mimusops caffra A. de Candolle
Mimusops elengi L.
Pouteria caimito Radlkofer
Sideroxylon americanum (Miller) T. D. Penn
Sideroxylon foetidissimum Jacquin
Sideroxylon salicifolium (L.) Lam.
Synsepalum dulcificum Schumacher & Thonning

Solanaceae
Brunfelsia lactea Krug & Urban
Brunfelsia nitida Bentham
Cestrum diurnum L.
Cestrum nocturnum L.
Solanum diphyllum L.
Solanum tampicense Dunal
Solanum torvum Swartz

Sterculiaceae
Sterculia ceramica R. Brown
Pterospermum acerifolium (L.) Willdenow

Tiliaceae
Grewia occidentalis L.
Grewia occidentalis L.

Theophrastaceae
Jacquinia armillaris Jacquin
Jacquinia aurantiaca Aiton

Urticaceae
Pouzolzia zeylanica (L.) Bennett

Verbenaceae
Avicennia germinans (L.) L.
Callicarpa americana L.
Duranta erecta L.
Petrea volubilis Jacquin

Vitaceae
*Parthenocissus quinquefolia (L.) Planchon
Vitis rotundifolia Michaux

Zygophyllaceae
Guaiacum officinale L.
Guaiacum sanctum L.

Angiosperms: monocotyledons

Palmae
Phoenix roebelenii O'Brien

Gymnosperms: Coniferales

Cupressaceae
Juniperus virginiana L.

Taxodiaceae
Taxodium distichum (L.) L. Richter

Potential Expansion in Distribution (Back to Top)

The potential for further spread of this scale insect in the western hemisphere is especially high for warm areas into which there is significant movement of living plants e.g., from Florida to Puerto Rico and other localities of the Caribbean Region, California, and Hawaii.

Invasion of natural areas is of paramount concern. Heavy infestations have been observed on diverse native plant species in numerous natural areas of southern Florida. Most of the native woody plants that are hosts of lobate lac scale in Florida are also native to the Antilles, implying that natural areas in the Caribbean Region could be threatened.

Pest Management Prospects (Back to Top)

The practical long-term option for control of lobate lac scale is via biological control with natural enemies. This is especially important because of this scale insect's wide host range and distribution in natural areas and urban landscapes. Initially work was conducted to find natural enemies of this scale insect in India and Sri Lanka, the native home of P. lobata. However, the lobate lac scale has now been identified as a new species, P. pseudolobata, which is known only as an adventive in Florida, the Bahamas, and Christmas Island. The native home of this species is not known, although it most likely is somewhere in Tropical Asia. The uncertainty regarding the origin of lobate lac scale has complicated research efforts to find natural enemies of the pest.

Control with insecticides is the only known short-term option. Products containing imidacloprid, a systemic insecticide, have been tested for control of lobate lac scale on shrubs and trees and found to be effective.

Selected References (Back to Top)