The lobate lac scale insect, Paratachardina lobata lobata (Chamberlin) (Kerriidae: Coccoidea: Hemiptera), a recent invader of southern Florida from India and Sri Lanka, now infests more than 160 economic and native plants in at least 49 plant families. It is killing wax myrtle (Myrica cerifera L.) and coco plum (Chrysobalanus icaco L.), valued native and horticultural plants in many locations. Intensive insecticide use in infested natural and residential areas is an unsuitable control approach because of the large numbers of plants infested, the high cost, and probable damage to non-target organisms. Biological control is a much needed solution for lobate lac scale. No parasitism has been detected in Florida. The lobate lac scale is native to India and Sri Lanka, occurring in localities south of 16 degrees N. latitude. The known host range includes some of the same species and families of host plants as it does in Florida, plus other plant groups on which it has yet to be detected in Florida. The natural enemies of the lobate lac scale have not been previously sought nor studied, but those of the related true lac scale of commerce are relatively well known, and some of these appear to have potential for biological control of the lobate lac scale. The most important natural enemies are predaceous Lepidoptera and Chrysopa species, and parasitic encyrtid and euplophid chalcidoid wasps. The chalcidoid wasps, with narrower host ranges, appear to be more suitable as potential biological control agents. Among these, Tachardiaephagus tachardiae Howard (Encyrtidae), seems particularly promising. It attacks the lobate lac scale, is known only from lac scale hosts, is not hyperparasitic, is one of the most important parasitoids of lac scale, has 9-12 generations per year, and occurs in the same climatic conditions as occur in southern Florida. It is recommended that this wasp and two other important parasitoids of the true lac scale, T. somervilli Madhihassen (Encyrtidae) and Coccophagus tschirchii Madhihassen (Eulophidae), be acquired and evaluated as potential biological control agents of the lobate lac scale. Explorations for unknown natural enemies of lobate lac scale in India and Sri Lanka should also be undertaken in locations with climatic similarity to that of southern Florida. Host specificity testing of species belonging to Florida's 12 native scale families (Coccoidea) and allied Hemiptera is advisable to define the potential host ranges and thus the safety of candidate biological control agents. The prospects of effective and safe biological control appear to be good. No native lac scales (Kerriidae) occur in Florida, and parasitoids are known that appear to be both narrow specialists and damaging to their host lac scales.
