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

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

mature females

crawler

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

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

twigs and small branches

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

wax-myrtle

Host Range

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).

mango

Potential Expansion in Distribution

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

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

• Chong J-H, Roda AL, Mannion CM. (2008). Mortality of the lobate lac scale Paratachardina pseudolobata (Hemiptera: Kerriidae) at near or below freezing temperatures. Florida Entomologist, 91 (4). http://www.fcla.edu/FlaEnt/fe91p674.pdf (February 2010).
• Hamon A. (2001). Lobate lac scale, Paratachardina lobata lobata (Chamberlin) (Hemiptera: Kerriidae). Pest Alert. http://www.doacs.state.fl.us/pi/enpp/ento/paratachardina.html (30 October 2002).
• Howard FW, Pemberton RW. 2003. The lobate lac scale, a new pest of trees and shrubs in Florida: implications for the Caribbean Region. Proceedings of the Caribbean Food Crops Society 39: 91-94.
• Howard FW, Steinberg B. 2005. Root drenches and topical insecticide treatments for control of the lobate lac scale, Paratachardina lobata (Chamberlin). Proceedings of the Florida State Horticultural Society 118: 314-31.
• Howard FW, Pemberton RW, Hodges GS, Steinberg B, McLean D, Liu H. 2006. Host plant range of lobate lac scale, Paratachardina lobate, in Florida. Proceedings of the Florida State Horticultural Society 119: 398-408.
• Kondo T, Gullan PJ. 2007. Taxonomic review of the lac insect genus Paratachardina Balachowsky (Hemiptera: Coccoidea: Kerriidae), with a revised key to genera of Kerriidae and description of two new species. Zootaxa 1617: 1-41.
• Miller DR, Ben-Dov Y. (2002) ScaleNet http://www.sel.barc.usda.gov/scalenet/scalenet.htm (30 October 2002).
• Pemberton RW, Nguyen R, Winotai A, Howard FW. 2006. Host acceptance trials of Kerria lacca (Kerriidae) parasitoids from northern Thailand on the pest lobate lac scale (Paratachardina lobata) (Kerriidae) in Florida. Florida Entomologist 89: 336-339.

Authors: F. W. Howard, University of Florida; Robert Pemberton, USDA; Avas Hamon, Division of Plant Industry; Greg S. Hodges, Division of Plant Industry; Bryan Steinberg, University of Florida; Catharine M. Mannion, University of Florida; David McLean, Broward Community College and Nova Southeastern University; Jeanette Wofford, Cooper City Arborist
Photographs: F. W. Howard, University of Florida
Project Coordinator: Thomas R. Fasulo, University of Florida
Publication Number: EENY-276
Publication Date: November 2002. Latest revision: February 2010.
Copyright 2002-2010 University of Florida

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