Microbial Control of Insect and Mite Pests of Citrus

Abstract Citrus is grown commercially in several different regions throughout the world, both for juicing and for fresh fruit consumption. All of these regions experience attack by a range of insect and mite pests. Although the exact species present in each pest complex differs, there are certain key pests that are common among most citrus-producing regions, such as armored scales, mealybugs, thrips, mites, and fruit flies. It is extremely rare to find an insect or mite pest that is not at least susceptible to attack by an entomopathogen; therefore, all citrus pests should be seen as potential targets and investigated as such. We review the entomopathogens (fungi, nematodes, viruses, and bacteria) recorded on citrus pests and focus on those microbes that have been tested and developed as biological control agents. Due to market requirements, future prospects for microbial control in citrus are bright. However, products will have to demonstrate similar efficacy to chemical alternatives. This may be achievable through integration with other modes of control, synergism and utilization of pathogen genes. Regulatory and market pressures on industries that supply discerning Western markets are likely to be the strongest driver in the growth of nonchemical pest control solutions, including microbial control.