The coffee berry borer (CBB), Hypothenemus hampei, is the most significant insect pest of coffee worldwide. Since CBB was detected in Puerto Rico in 2007 and Hawaii in 2010, coffee growers from these islands are facing increased costs, reduced coffee quality, and increased pest management challenges. Here, we outline the CBB situation, and summarize the findings of growers, researchers, and extension professionals working with CBB in Hawaii. Recommendations for the Integrated Pest Management (IPM) program for CBB in Hawaiian Islands and Puerto Rico include: (1) establish a CBB monitoring program, (2) synchronize applications of insecticides with peak flight activity of CBB especially during the early coffee season, (3) conduct efficient strip-picking as soon as possible after harvest and perform pre-harvest sanitation picks in CBB hotspots if needed, (4) establish protocols to prevent the escape of CBB from processing areas and when transporting berries during harvest, and (5) stump prune by blocks. Progress achieved includes the introduction of the mycoinsecticide Beauveria bassiana to coffee plantations, the coordination of area-wide CBB surveys, the establishment and augmentation of native beetle predators, and an observed reduction of CBB populations and increased coffee quality where IPM programs were established. However, CBB remains a challenge for coffee growers due to regional variability in CBB pressures, high costs, and labor issues, including a lack of training and awareness of CBB management practices among growers.

Since its recent establishment in Hawaii, the coffee berry borer (CBB), Hypothenemus hampei (Coleoptera: Curculionidae), threatens yields, quality, and price of coffee production. A limited number of insecticides (primarily Beauveria bassiana) are used to control CBB with minimal disruption in this agroecosystem. We evaluated two insecticide spray strategies across eight coffee farms in the Kona and Ka'u districts of Hawaii Island. Coffee growers sprayed insecticides approximately monthly (calendar basis) or else in response to CBB field monitoring data (threshold based). Overall, farms adopting spray thresholds performed more insecticide applications early in the season (May to July), but significantly fewer overall, when compared with calendar-based strategies (i.e., 4-5 vs. 7-11 seasonal sprays, respectively). Generalized linear models assessing the variability in CBB infestation rates, berry penetration, and infection by B. bassiana indicated that threshold-based sprays provided equivalent CBB control compared with calendar ones. When corrected for yield, there were economic savings for threshold-vs. calendar-based spray programs (i.e., cost 5.4 vs. 11.8% of gross yield). Total defects in processed coffee after harvest were statistically similar between the two spray regimes, i.e., 8.5 ± 1.0% and 10.4 ± 1.7%, respectively. We hypothesize that B. bassiana applied early in the season is more effective, since the fungus targets initial CBB infestations when the prolonged location of founder females in the outer berry endosperm favors its infection. Our study suggests that spray timing for CBB based on field monitoring data can reduce costs; however, additional measures, such as field and post-harvest sanitation, are necessary to achieve sustainable CBB control in the Islands.

The coffee berry borer (CBB), Hypothenemus hampei Ferrari (Coleoptera: Curculionidae: Scolytinae) is a recent invader to Hawaii. To date, limited information regarding the seasonal phenology of this pest on the islands limits the implementation of integrated control strategies. As part of a coffee farmer training program, we monitored CBB flight activity in 15 coffee plantations (Kona and Kau Districts) over 10 mo with methanol-ethanol (3:1 ratio) baited traps. Concurrently, we quantified CBB infestation and penetration rates inside developing coffee berries through the end of harvest. Approximately 1 million CBB were captured, with the highest activity (e.g., >500 CBB/trap/wk) in December through February, coinciding with end of main regional harvesting periods. Relatively high activity (>250 CBB/trap/wk) was also observed during berry development, in May and June (Kona) and June and July (Kau). Field infestation rates were higher overall in Kau (9.6 ± 1.1%) compared with coffee plantations in Kona (4.7 ± 0.4%). Linear regression investigated relationships between CBB trap data and berry infestation rates. Trap catch data generally correlated better with the proportion of shallow entries (AB position) compared with deeper penetrations (CD position) or total infestation. Pearson correlation coefficients based on different parameters (i.e., region, altitude, and berry phenology) revealed positive and mostly significant correlations between these variables (R values 0.410 to 0.837). Timing peak flight activity of CBB with insecticide applications will help coffee growers improve pest control. The ability of trap data to calculate reliable economic (action) thresholds for the CBB is discussed.

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.

The coffee berry borer (CBB), Hypothenemus hampei Ferrari, a recent invader to Hawaii, is impacting coffee growers by reducing yields and quality and increasing production costs. Monitoring strategies are needed to assess infestations and where control operations are warranted, and evaluate their effectiveness. To develop and validate a fixed-precision sequential sampling plan, an intensive CBB sampling programme was conducted in 17 small farms in Kona and Kau districts in the Big Island in 2016/17. At each location, 30 trees/ha were monitored at 2–4 week intervals. Results show that the CBB has an aggregated spatial distribution based on Taylor's power law parameters. According to Green's stop line formula, between 6 and 50 coffee branches per ha (sample unit) are required to estimate infestation rates of 1.5–2.5% infested green berries (suggested economic threshold) with a precision fixed at 10 to 25%. Concurrently, a modified strategy was tested on 14 farms, in which only infested green berries (not total) was counted. The standard and modified sampling methods were highly correlated (R2 ≥ 0.98), while the modified approach required on average only 35 min (27% less time) to complete, with an additional 24 min taken to observe the position of the CBB inside the berry. Our data also show that berry infestation rates of CBB prior to harvest were a good predictor of the total defects resulting in processed green coffee from these farms (Pearson's r coefficient of 0.82). Our findings support improved sampling for the CBB under Hawaiian conditions using a simpler and faster monitoring strategy based on counting green infested berries.