To Spray or Not to Spray: A Decision Analysis of Coffee Berry Borer in Hawaii

Establishing an Integrated Pest Management Program for Coffee Berry Borer (Hypothenemus hampei) in Hawaii and Puerto Rico Coffee Agroecosystems: Achievements and Challenges

Coffee berry borer (CBB) is the most serious insect pest of coffee worldwide, causing significant reductions in yield and quality. Following the introduction of CBB to Puerto Rico (2007) and Hawaii (2010), researchers, extension agents, industry representatives, and coffee growers have worked together to develop an integrated pest management (IPM) program that is both effective and economically feasible for each island. Since the introduction of the IPM program in Hawaii, research efforts have led to a better understanding of CBB population dynamics, as well as optimized monitoring, cultural practices, and commercial Beauveria bassiana applications. As a result of these efforts, a substantial reduction in average CBB infestation and an increase in coffee yields and quality have been documented in Hawaii over the last decade. However, significant challenges remain in addressing high production and labor costs, limited availability of labor, and a lack of training for field workers in both regions. Although considerable effort has gone into research to support CBB IPM in Hawaii and Puerto Rico, the adoption of these strategies by coffee farmers needs to be increased. More diversified methods of outreach and education are needed to reach growers in rural, isolated areas. Significant gaps exist in the ability and willingness of growers and workers to access and digest information online, emphasizing the importance of on-farm workshops and farmer-to-farmer teaching. Additional methods of training are needed to help coffee farmers and field workers learn how to properly conduct cultural controls and optimize the use of biological control agents such as B. bassiana.

Frequent and efficient harvesting as an economically viable strategy to regulate coffee berry borer on commercial farms in Hawaii

Coffee is the second most economically important agricultural crop in Hawaii, valued at around $175M for green and roasted coffee in the 2021-2022 season. With the introduction of coffee berry borer (CBB, Hypothenemus hampei Ferrari) to Hawaii in 2010, growers have faced a significant challenge in producing the specialty coffee that the region is known for. This tiny beetle infests the coffee seed and reduces the yield and quality of coffee products. While field sanitation, frequent harvesting and strip-picking are known to be essential for controlling CBB, the associated costs and benefits of these cultural control practices have not been estimated for Hawaii. In the present study, we examined two CBB management strategies across 10 commercial coffee farms on Hawaii Island: (i) conventional management including frequent sprays of pesticides and few rounds of sanitation and harvesting, and (ii) cultural control-focused management consisting of few sprays of pesticides and frequent sanitation and harvesting. Cultural management resulted in significantly lower mean CBB infestation (4.6% vs. 9.0%), total defects (5.5% vs. 9.1%), and CBB damage to processed coffee (1.6% vs. 5.7%) compared to conventional management. Additionally, yields were higher (mean increase of 3,024 lbs of cherry/acre) and harvested more efficiently (4.8 vs. 7.9 raisins/tree) on culturally managed vs. conventional farms. Lastly, the cost of chemical controls was 55% lower and the net benefit of frequent harvesting was 48% higher on cultural vs. conventional farms. Our findings demonstrate that frequent and efficient harvesting is an effective and economically viable alternative to frequent pesticide applications.

Economic Benefits from Managing Coffee Berry Borer (Hypothenemus hampei) in Hawaii

Coffee berry borer (CBB) is considered the most damaging insect pest of coffee worldwide. CBB was first detected on Hawai'i Island in 2010, and quickly spread throughout the state's coffee-growing regions. With the introduction of this pest, Hawaii's small yet economically important coffee industry was changed forever with growers facing significantly higher production and labor costs, as well as decreased yield and coffee quality. We assessed the economic benefits of managing CBB based on three strategies that emerged in Hawaii over the last decade: (1) the use of the entomopathogenic fungus Beauveria bassiana alone, (2) early integrated pest management (IPM), which combined monitoring and sanitation with spraying B. bassiana, and (3) research-based IPM, which focused on CBB biology in Hawaii, optimization of monitoring, B. bassiana applications, and cultural controls. From 2011 to 2021, the economic benefits from managing CBB were USD 52 million using B. bassiana alone, USD 69 million from early IPM, and USD 130 million from research-based IPM, for a total of USD 251 million from all management. Our findings suggest that all types of management provide economic benefits to Hawaii growers, but management strategies based on Hawaii-specific research have provided the greatest gains in coffee yield, price, and revenue.

Field Efficacy of Spinetoram for the Management of Coffee Berry Borer (Hypothenemus hampei)

Coffee berry borer (CBB), Hypothenemus hampei, is a damaging insect pest of coffee worldwide. CBB has recently been introduced to Hawaii, so management techniques are still being developed for sustainable and cost-efficient approaches for the effective control of this pest. Field trials were conducted to evaluate the use of spinetoram on CBB infestation and bean damage compared to Beauveria bassiana and an untreated control. Initial CBB infestations were similar, and the treatments resulted in no detectable differences in subsequent new infestations. Damage to the coffee beans was reduced by both spinetoram and B. bassiana compared to controls as the mortality of adult beetles resulting from the treatments prevented them from moving into the bean (C/D position) from the berry (A/B position). The mortality of adult beetles also prevented reproduction, subsequently reducing future CBB populations in the field. When applied to infested berries, spinetoram reduced live beetle populations in the A/B position by 73% and CBBs in the C/D position by 70% compared to the water control, whereas applications of B. bassiana reduced beetles in the C/D position by 37% but had no effect on the live A/B population. An integrated pest management program is recommended for the effective control of CBBs, and the use of spinetoram applications when adult beetles are in the A/B position appears to have potential as another management tool.

Coffee Berry Borer (Hypothenemus hampei), a Global Pest of Coffee: Perspectives from Historical and Recent Invasions, and Future Priorities

Coffee berry borer (Hypothenemus hampei (Ferrari), CBB) has invaded nearly every coffee-producing country in the world, and it is commonly recognized as the most damaging insect pest of coffee. While research has been conducted on this pest in individual coffee-growing regions, new insights may be gained by comparing and contrasting patterns of invasion and response across its global distribution. In this review, we explore the existing literature and focus on common themes in the invasion biology of CBB by examining (1) how it was introduced into each particular region and the response to its invasion, (2) flight activity and infestation patterns, (3) economic impacts, and (4) management strategies. We highlight research conducted over the last ten years in Hawaii as a case study for the development and implementation of an effective integrated pest management (IPM) program for CBB, and also discuss biosecurity issues contributing to incursion and establishment. Potential areas for future research in each of the five major components of CBB IPM (monitoring and sampling, cultural, biological, chemical, and physical controls) are also presented. Finally, we emphasize that outreach efforts are crucial to the successful implementation of CBB IPM programs. Future research programs should strive to include coffee growers as much as possible to ensure that management options are feasible and cost-effective.

The coffee agroecosystem: bio-economic analysis of coffee berry borer control (Hypothenemus hampei)

Coffee, after petroleum, is the most valuable commodity globally in terms of total value (harvest to coffee cup). Here, our bioeconomic analysis considers the multitude of factors that influence coffee production. The system model used in the analysis incorporates realistic field models based on considerable new field data and models for coffee plant growth and development, the coffee/coffee berry borer (CBB) dynamics in response to coffee berry production and the role of the CBB parasitoids and their interactions in control of CBB. Cultural control of CBB by harvesting, cleanup of abscised fruits, and chemical sprays previously considered are reexamined here to include biopesticides for control of CBB such as entomopathogenic fungi (Beauveria bassiana, Metarhizium anisopliae) and entomopathogenic nematodes (Steinernema sp., Heterorhabditis). The bioeconomic analysis estimates the potential of each control tactic singly and in combination for control of CBB. The analysis explains why frequent intensive harvesting of coffee is by far the most effective and economically viable control practice for reducing CBB infestations in Colombia and Brazil.

Coffee berry borer (Hypothenemus hampei) (Coleoptera: Curculionidae) development across an elevational gradient on Hawai'i Island: Applying laboratory degree-day predictions to natural field populations

Coffee berry borer (CBB, Hypothenemus hampei) (Coleoptera: Curculionidae: Scolytinae) is the most destructive pest of coffee worldwide. Information on CBB development times can be used to predict the initiation of new infestation cycles early in the coffee-growing season and thus inform the timing of insecticide applications. While laboratory estimates of CBB development under constant conditions exist, they have not been applied under the heterogeneous environmental conditions that characterize many coffee-growing regions. We measured CBB development times and abundance in commercial coffee farms across an elevational gradient on Hawai‘i Island and applied thermal accumulation models from previous laboratory studies to test their fit to field data. Artificial lures were used to infest coffee berries at five farms ranging in elevation from 279–792 m, and weather variables were monitored at macro (farm-level) and micro (branch-level) scales. CBB development was followed in the field from the time of initial berry infestation by the founding female through the development of F1 mature adults. Mean development time from egg to adult across all sites was 38.5 ± 3.46 days, while the mean time required for the completion of a full life cycle (from time of infestation to presence of mature F1 females) was 50.9 ± 3.35 days. Development time increased with increasing elevation and decreasing temperature. Using macro-scale temperature data and two different estimates for the lower temperature threshold (14.9°C and 13.9°C), we estimated a mean requirement of 332 ± 14 degree-days and 386 ± 16 degree-days, respectively, from the time of berry infestation to the initiation of a new reproductive cycle in mature coffee berries. Similar estimates were obtained using micro-scale temperature data, indicating that macro-scale temperature monitoring is sufficient for life-cycle prediction. We also present a model relating elevation to number of CBB generations per month. Our findings suggest that CBB development times from laboratory studies are generally applicable to field conditions on Hawai‘i Island and can be used as a decision support tool to improve IPM strategies for this worldwide pest of coffee.