Integrated Pest Management Strategies for Asian Citrus Psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) and Huanglongbing in Citrus for Sarawak, East Malaysia, Borneo

Abstract

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, transmits ‘Candidatus Liberibacter asiaticus’ (CLas), a phloem-limited bacterium associated with the severe Asian form of huanglongbing (HLB), and the most destructive disease of citrus. The pathogen and the psyllid, both of South Asian origin, are now widespread in citrus regions of Asia and the Americas. There is no cure for the disease. Application of synthetic pesticides, in some instances more frequently than fortnightly, to minimise incidence of ACP in citrus orchards, has not prevented inevitable impacts of the disease in regions of Asia where CLas is present. Despite the inevitable spread of the disease, significant progress has been made in Sarawak since the mid-1990s towards effectively implementing integrated pest management (IPM) programs for stemming the impact of the disease and detrimental consequences of over-reliance on synthetic pesticides. Growers are encouraged to plant pathogen-free trees, remove diseased trees, monitor incidence of the psyllid, and to use pesticides judiciously to reduce their detrimental impacts on natural enemies. Knowledge has been enhanced through research on seasonal incidence of the psyllid, use of mineral oils, development of protocols and iodine–starch test kits for detecting infected trees, PCR for confirming the presence of CLas in symptomatic leaves, methods for monitoring incidence the psyllid, and training extension staff and growers. However, major impediments to increasing the average longevity of trees beyond <5 years in poorly managed orchards, based on marcotting (air layering), and >12 years in well-managed orchards, based on pathogen-free trees, still need to be addressed. These include grower knowledge, marcotting, aggressive marketing of synthetic pesticides, high prices of mineral oils, spray application procedures, and better reliance on natural enemies of the psyllid.

Detection of Candidatus Liberibacter asiaticus and five viruses in individual Asian citrus psyllid in China

“…The prevention and control of its vector, ACP, is one of the most important measures to prevent HLB epidemics. ACP population control relies heavily on insecticides, but chemical strategies lead to the development of chemical resistance among ACP populations, pollute the environment, and may have negative effects on beneficial organisms ( Leong et al., 2022 ). To avoid the development of insecticide-resistant insect populations, biological control strategies are being considered.…”

Distribuição de Diaphorina citri (Hemiptera: Liviidae) e detecção de Candidatus Liberibacter asiaticus em regiões citrícolas do Paraná

“…As plantas cítricas estão nesta posição de destaque, decorrente de sua ampla plasticidade fenotípica, junto às características sensoriais e qualidade de seus frutos (SIQUEIRA; SALOMÃO, 2016). Entretanto, existem fatores limitantes para obter de alta produtividade, como a ocorrência de pragas e doenças (LEONG et al, 2022).…”

Thirty‐minute test to detect insecticide resistance under field conditions: the case of the Asian citrus psyllid

“…The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is found in all citrus‐growing areas of the world, 1 with devastating effects in Pakistan, 2 Malaysia, 3 China, 1 the United States of America, 4 Mexico 5 and Brazil 6 . This species feeds on important crops such as the Mexican lemon Citrus aurantifolia Swingle, 5 Valencia orange C. sinensis L Osbeck, 7 grapefruit C. paradisi MacFad 8 and mandarin C. reticulata Blanco 9 .…”