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Title: THE LOBATE LAC SCALE, A NEW INSECT PEST OF TREES AND SHRUBS IN FLORIDA: IMPLICATIONS OF THE CARIBBEAN REGION

Author
item HOWARD, FOREST - UF, DAVIE, FL
item Pemberton, Robert

Submitted to: Caribbean Food Crops Society Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/20/2004
Publication Date: 12/20/2004
Citation: Howard, F.W., Pemberton, R.W. 2004 The lobate lac scale, a new insect pest of trees and shrubs in florida: implications of the caribbean region. Caribbean Food Crops Society Proceedings. 38:91-94

Interpretive Summary: The lobate lac scale, Paratachardina lobata, was first detected in the Western Hemisphere in southern Florida in 1999. Subsequent examination of specimens collected from New Providence Island in the Bahamas in 1992, determined these as the lobate lac scale. The lobate lac scale, which attacks woody trees and shrubs, is native to India and Sri Lanka. This sucking insect has reached alarming densities in southern Florida where it is damaging many native, tropical fruit, and landscape trees. The lobate lac scale also has large damaging populations on New Providence and Grand Bahama Islands in the Bahamas. The scale damages plants by the removal of sap and by the secretion of honeydew, which promotes the growth of sooty mould which covers infested plants and nearby uninfested plants. In Florida, high infestations of the scale cause branch dieback to many species and kill some species. Of the commercial fruits, carambola, sugar apple, and atemoya are particularly susceptible but mangos and other valued fruits are also attacked. Citrus appears to be immune with only occasional individual scales appearing on grapefruit. Figs, coco plums, and wax myrtles are among the most susceptible landscape and native plants; all can be killed by high infestations of this scale. There are not many collection records of the lobate lac scale in India and Sri Lanka but it is known to occur at and below 16 degrees N. latitude. This range and its occurrence in southern Florida at 26 N., suggest that much of the New World tropics and subtropics may be climatically suitable for this insect. The floristic and crop plant similarities between Florida, the Bahamas and Caribbean, indicate that large numbers of valued plants could be attacked if the scale reaches the Caribbean. The movement of infested plants from Florida or the Bahamas to the Caribbean could easily introduce the lobate lac scale, and for this reason the movement of woody plants from infested to uninfested areas needs to be carefully monitored. In addition, the Caribbean entomologists need to be alert to the potential spread of the scale into their areas. Imidochloprid, also known a Merit, used as a soil drench effectively controls the lobate lac scale, but the chemical is expensive and likely unsuitable for many natural areas where pesticide use is restricted. A biological control program has been established to seek and implement natural enemies from the native area to the infested regions.

Technical Abstract: The lobate lac scale, Paratachardina lobata, was first detected in the Western Hemisphere in southern Florida in 1999. Subsequent examination of specimens collected from New Providence Island in the Bahamas in 1992, determined these as the lobate lac scale. The lobate lac scale, which attacks woody trees and shrubs, is native to India and Sri Lanka. This sucking insect has reached alarming densities in southern Florida where it is damaging many native, tropical fruit, and landscape trees. The lobate lac scale also has large damaging populations on New Providence and Grand Bahama Islands in the Bahamas. The scale damages plants by the removal of sap and by the secretion of honeydew, which promotes the growth of sooty mould which covers infested plants and nearby uninfested plants. In Florida, high infestations of the scale cause branch dieback to many species and kill some species. Of the commercial fruits, carambola, sugar apple, and atemoya are particularly susceptible but mangos and other valued fruits are also attacked. Citrus appears to be immune with only occasional individual scales appearing on grapefruit. Figs, coco plums, and wax myrtles are among the most susceptible landscape and native plants; all can be killed by high infestations of this scale. There are not many collection records of the lobate lac scale in India and Sri Lanka but it is known to occur at and below 16 degrees N. latitude. This range and its occurrence in southern Florida at 26 N., suggest that much of the New World tropics and subtropics may be climatically suitable for this insect. The floristic and crop plant similarities between Florida, the Bahamas and Caribbean, indicate that large numbers of valued plants could be attacked if the scale reaches the Caribbean. The movement of infested plants from Florida or the Bahamas to the Caribbean could easily introduce the lobate lac scale, and for this reason the movement of woody plants from infested to uninfested areas needs to be carefully monitored. In addition, the Caribbean entomologists need to be alert to the potential spread of the scale into their areas. Imidochloprid, also known a Merit, used as a soil drench effectively controls the lobate lac scale, but the chemical is expensive and likely unsuitable for many natural areas where pesticide use is restricted. A biological control program has been established to seek and implement natural enemies from the native area to the infested regions.