Economic value of conservation biological control for management of the Asian citrus psyllid, vector of citrus Huanglongbing disease

Abstract

BACKGROUND Huanglongbing (HLB) is the most devastating disease associated with citrus, transmitted by its principal vector Diaphorina citri, the Asian citrus psyllid (ACP). At present, the only effective action against this pathosystem is vector management. Owing to the severity of HLB, vector management mostly relies on highly frequent insecticide applications. While this strategy may be able to maintain the economic viability of citrus operations in the short term, it raises numerous concerns for the development of D. citri insecticide resistance as well as further impacts to human health and environmental sustainability. The present study estimates and allocates HLB management costs resulting from the loss of ACP conservation biological control (CBC) within vector‐intensive insecticide management regimes. Scenarios under different degrees of CBC were simulated and vector populations were estimated. CBC costs were calculated by subtracting the total HLB related costs of the scenarios with high ACP biological control to those of the scenarios with no or low biological control. RESULTS We have estimated that an agroecosystem without an effective CBC management program for the suppression of ACP would result in predicted economical loss ranging from $1150 to $2000 per hectare. The proposed model translates to a total economic loss of approximately $300 million to Florida's citrus industry per season (36.42% of total Florida processed oranges production value). CONCLUSION These results help to identify the long‐term viability of the HLB management strategies currently implemented and highlight the urgency of finding a definitive and sustainable solution to HLB. © 2019 Society of Chemical Industry

The Asian Citrus Greening Disease (Huanglongbing): Evidence Note on Invasiveness and Potential Economic Impacts for East Africa

“…Nonetheless, to implement IPM of D. citri, it is necessary to monitor adult and nymphal populations since information collected can be used to make decisions about spray applications. Effectiveness of ACP spray programmes can also be evaluated by monitoring population trends using visual inspections as well as methods such as tap-sampling (hitting a branch with a blunt object to dislodge adults), sticky traps and sweep-net sampling, which have all been found to have similar sensitivity per sampling effort (Monzo and Stansly, 2020). Stem taps have the advantage of rapid data processing time and less sampling effort required to attain similar precision levels at all but the lowest ACP densities and are thus recommended for large-scale ACP monitoring plans (Monzo and Stansly, 2020), whilst sticky traps are advisable for early ACP detection and to monitor young plantations where stem tapping is not efficient.…”

Response surface methodology reveals proportionality effects of plant species in conservation plantings on occurrence of generalist predatory arthropods

“…Conservation biological control can be an effective approach for suppressing pests in citrus [68][69]87]. In the absence of frequent insecticidal applications, many types of predaceous arthropods attack D. citri in citrus [55,56,60].…”

“…Studies will evaluate whether a single strip of conservation plants placed along the grove border is as effective in suppressing psyllids as other types of planting arrangement, such as multiple strips planted at intervals throughout the grove or a cover crop grown across the grove understory. Finally, analyses, such as that conducted by Monzo and Stansly [68] which examined costs and benefits of conservation biological control across different yield-loss scenarios, will be needed to demonstrate the economic feasibility of implementing conservation plantings as a means of suppressing D. citri.…”

“…The intensive dependence on chemical control has adversely affected populations of natural enemies residing in or near citrus groves [56,66,67]. As chemical suppression is reduced, natural enemies are expected to return to citrus groves [68], and growers are beginning to consider biological control as an option to cut costs. A recent analysis indicated that commercial citrus growers in Florida could make significant economic savings by applying insecticides only during a few periods when they are most effective [68].…”

“…As chemical suppression is reduced, natural enemies are expected to return to citrus groves [68], and growers are beginning to consider biological control as an option to cut costs. A recent analysis indicated that commercial citrus growers in Florida could make significant economic savings by applying insecticides only during a few periods when they are most effective [68]. This approach would make insecticide applications more effective; and, the reduction in spray frequency would permit natural enemies to enter the groves and provide a high level of D. citri suppression.…”