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Coffee berry borer (CBB, Hypothenemus hampei Ferrari) is the most serious insect pest of coffee worldwide, yet little is known about the effect that weather variables have on CBB flight activity. We sampled flying female CBB adults bi-weekly over a three-year period using red funnel traps baited with an alcohol lure at 14 commercial coffee farms on Hawaii Island to characterize seasonal phenology and the relationship between flight activity and five weather variables. We captured almost 5 million scolytid beetles during the sampling period, with 81–93% of the trap catch comprised of CBB. Of the captured non-target beetles, the majority were tropical nut borer, black twig borer and a species of Cryphalus . Two major flight events were consistent across all three years: an initial emergence from January-April that coincided with early fruit development and a second flight during the harvest season from September-December. A generalized additive mixed model (GAMM) revealed that mean daily air temperature had a highly significant positive correlation with CBB flight; most flight events occurred between 20–26°C. Mean daily solar radiation also had a significant positive relationship with flight. Flight was positively correlated with maximum daily relative humidity at values below ~94%, and cumulative rainfall up to 100 mm; flight was also positively correlated with maximum daily wind speeds up to ~2.5 m/s, after which activity declined. Our findings provide important insight into CBB flight patterns across a highly variable landscape and can serve as a starting point for the development of flight prediction models.

The Male Annihilation Technique (also termed the Male Attraction Technique; “MAT”) is often used to eradicate pestiferous tephritid fruit flies, such as Bactrocera dorsalis (Hendel). MAT involves the application of male-specific attractants combined with an insecticide in spots or stations across an area to reduce the male population to such a low level that suppression or eradication is achieved. Currently, implementations of MAT in California and Florida targeting B . dorsalis utilize the male attractant methyl eugenol (ME) accompanied with a toxicant, such as spinosad, mixed into a waxy, inert emulsion STATIC ME (termed here “SPLAT-MAT-ME”). While highly effective against ME-responding species, such applications are expensive owing largely to the high cost of the carrier matrix and labor for application. Until recently the accepted protocol called for the application of approximately 230 SPLAT-MAT-ME spots per km 2 ; however, findings from Hawaii suggest a lower density may be more effective. The present study adopted the methods of that earlier work and estimated kill rates of released B . dorsalis under varying spot densities in areas of California and Florida that have had recent incursions of this invasive species. Specifically, we directly compared trap captures of sterilized marked B . dorsalis males released in different plots under three experimental SPLAT-MAT-ME densities (50, 110, and 230 per km 2 ) in Huntington Beach, CA; Anaheim, CA; and Sarasota-Bradenton, FL. The plots with a density of 110 sites per km 2 had a significantly higher recapture proportion than plots with 50 or 230 sites per km 2 . This result suggests that large amounts of male attractant may reduce the ability of males to locate the source of the odor, thus lowering kill rates and the effectiveness of eradication efforts. Eradication programs would directly benefit from reduced costs and improved eradication effectiveness by reducing the application density of SPLAT-MAT-ME.

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.

Tephritid fruit flies, such as the melon fly, Zeugodacus cucurbitae , are major horticultural pests worldwide and pose invasion risks due primarily to international trade. Determining movement parameters for fruit flies is critical to effective surveillance and control strategies, from setting quarantine boundaries after incursions to development of agent-based models for management. While mark-release-recapture, flight mills, and visual observations have been used to study tephritid movement, none of these techniques give a full picture of fruit fly movement in nature. Tracking tagged flies offers an alternative method which has the potential to observe individual fly movements in the field, mirroring studies conducted by ecologists on larger animals. In this study, harmonic radar (HR) tags were fabricated using superelastic nitinol wire which is light (tags weighed less than 1 mg), flexible, and does not tangle. Flight tests with wild melon flies showed no obvious adverse effects of HR tag attachment. Subsequent experiments successfully tracked HR tagged flies in large field cages, a papaya field, and open parkland. Unexpectedly, a majority of tagged flies showed strong flight directional biases with these biases varying between flies, similar to what has been observed in the migratory butterfly Pieris brassicae . In field cage experiments, 30 of the 36 flies observed (83%) showed directionally biased flights while similar biases were observed in roughly half the flies tracked in a papaya field. Turning angles from both cage and field experiments were non-random and indicate a strong bias toward continued “forward” movement. At least some of the observed direction bias can be explained by wind direction with a correlation observed between collective melon fly flight directions in field cage, papaya field, and open field experiments. However, individual mean flight directions coincided with the observed wind direction for only 9 out of the 25 flies in the cage experiment and half of the flies in the papaya field, suggesting wind is unlikely to be the only factor affecting flight direction. Individual flight distances (meters per flight) differed between the field cage, papaya field, and open field experiments with longer mean step-distances observed in the open field. Data on flight directionality and step-distances determined in this study might assist in the development of more effective control and better parametrize models of pest tephritid fruit fly movement.

Male Annihilation Technique (MAT) is a key tool to suppress or eradicate pestiferous tephritid fruit flies for which there exist powerful male lures. In the case of Bactrocera dorsalis (Hendel), a highly invasive and destructive species, current implementations of MAT utilize a combination of the male attractant methyl eugenol (ME) and a toxicant such as spinosad (\"SPLAT-MAT-ME\") applied at a high density with the goal of attracting and killing an extremely high proportion of males. We conducted direct comparisons of trap captures of marked B. dorsalis males released under three experimental SPLAT-MAT-ME site densities (110, 220, and 440 per km2) near Hilo, Hawaii using both fresh and aged traps to evaluate the effectiveness of varying densities and how weathering of the SPLAT-MAT-ME formulation influenced any density effects observed. Counterintuitively, we observed decreasing effectiveness (percent kill) with increasing application density. We also estimated slightly higher average kill for any given density for weathered grids compared with fresh. Spatial analysis of the recapture patterns of the first trap service per replicate x treatment reveals similar positional effects for all grid densities despite differences in overall percent kill. This study suggests that benefits for control and eradication programs would result from reducing the application density of MAT against B. dorsalis through reduced material use, labor costs, and higher effectiveness. Additional research in areas where MAT programs are currently undertaken would be helpful to corroborate this study's findings.

The olive fruit fly Bactrocera oleae (Diptera: Tephritidae) was detected on Maui and Hawai’i Islands in 2019, affecting yields and quality of the state’s emerging olive oil industry. Given previous parasitoid releases to control other invasive frugivorous tephritids in Hawai’i, we were interested in determining whether these parasitoids were naturally targeting recent olive fly invaders in field, if local olive cultivar differences affected parasitization rates, and if there was a seasonal pattern of parasitization that could inform future management decisions. To address these questions, we collected data from olive growing in Hawai’i during 2021 and 2022. During the fruiting season we collected monthly samples and reared out B. oleae in the lab. We detected two previously introduced braconid wasps: first Diachasmimorpha tryoni during 2021 and 2022 and later Fopius arisanus during the 2022 collection. Cultivar effects were limited to a single site in our study, where more D. tryoni were reared from ‘Arbequina’ olives. Seasonality of olive fruit fly and parasitoid activity was earlier in lower elevation sites, as expected based on tree phenology and temperature-dependent insect development. This represents the first report of D. tryoni parasitism activity against B. oleae and may reflect elevational effects combined with the ecological complexity in interactions between multiple invasive arthropod pests, their invasive and cultivated plant hosts, and introduced braconid parasitoids.

In the United States of America, delimitation trapping surveys with square grids have been used for decades for exotic insects without rigorous evaluation. We used simulations to investigate the effectiveness of two representative designs: an 8-km grid for Acrolepiopsis assectella (leek moth) and a 14.5-km grid for Ceratitis capitata (Mediterranean fruit fly, “Medfly”). We investigated grid compositions and design factors, measuring performance as the mean probability of pest capture over all traps, p (capture), and designed improved grids for both species. For the standard designs, p (capture) was 0.86 for leek moth and 0.71 for Medfly, with the latter performing better due to greater lure and trap attractiveness. For both designs, 86 percent or more of mean p (capture) came from core area captures. Egress testing indicated that both grids were oversized. An improved grid for leek moths would use 177 traps in a 4.8-km diameter circle, which had mean p (capture) = 0.73 and reduced the cost by 80 percent. The best Medfly grid was a 4.8-km diameter circle with 232 traps, which gave mean p (capture) of 0.66 and reduced the cost by 86 percent. Simulation may be used to improve trapping survey plans, often saving significantly on costs while maintaining survey performance.

Attractant-based traps are a cornerstone of detection, delimitation and eradication programs for pests such as tephritid fruit flies. The ideal trap and lure combination has high attraction (it brings insects to the trap from a distance) and high capture efficiency (it has a high probability of capturing the insect once it arrives at the trap). We examined the effect of an insecticide (DDVP) in combination with a pheromone lure (trimedlure) on capture of Ceratitis capitata using 1) digital images of surfaces of a Jackson trap analyzed via computer vision, and 2) counts of the number of flies caught in the trap and in the area under the trap. Our results indicate no significant difference in trap capture without or with insecticide (means ± SD = 324 ±135 and 356 ±108, respectively). However, significantly more dead flies were found around the trap with insecticide (92 ±53 with insecticide compared with 35 ±22 without), suggesting a possible decrease in trap efficiency due to mortality before insects enter the trap. Indeed, the average number of flies detected on all surfaces of the traps with insecticide was lower than that for lure-only (4.15±0.39 vs 8.30±1.18), and both were higher than control (no lure: 0.76 ±0.08). We found that the majority of fly sightings, 71% of the total, occurred on the inside panels of the lure-only traps, suggesting that increased efficiency of the Jackson trap may be obtained by adding a contact insecticide to those surfaces.

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.

Determining movement parameters for pest insects such as tephritid fruit flies is critical to developing models which can be used to increase the effectiveness of surveillance and control strategies. In this study, harmonic radar was used to track wild-caught male Queensland fruit flies (Qflies), Bactrocera tryoni, in papaya fields. Experiment 1 continuously tracked single flies which were prodded to induce movement. Qfly movements from this experiment showed greater mean squared displacement than predicted by both a simple random walk (RW) or a correlated random walk (CRW) model, suggesting that movement parameters derived from the entire data set do not adequately describe the movement of individual Qfly at all spatial scales or for all behavioral states. This conclusion is supported by both fractal and hidden Markov model (HMM) analysis. Lower fractal dimensions (straighter movement paths) were observed at larger spatial scales (> 2.5 m) suggesting that Qflies have qualitatively distinct movement at different scales. Further, a two-state HMM fit the observed movement data better than the CRW or RW models. Experiment 2 identified individual landing locations, twice a day, for groups of released Qflies, demonstrating that flies could be tracked over longer periods of time.