Sublethal exposure to an emulsion based on Pogostemon cablin (Lamiaceae) essential oil impairs digestibility, feeding, fecundity, and mobility of the coffee berry borer, Hypothenemus hampei

The global search for eco-friendly and human-safe pesticides has intensified, and research on essential oils (EOs) has expanded due to their remarkable insecticidal activities and apparent human-safe. Despite this, most of the literature focuses on short-term and simplified efforts to understand lethal effects, with only a few comprehensive studies addressing sublethal exposures. To fill this shortcoming, we explore the lethal and sublethal effects of Pogostemon cablin (Lamiaceae) EO and an EO-based emulsion (18%) using the coffee berry borer Hypothenemus hampei Ferrari (Coleoptera: Curculionidae: Scolytinae) as a model. First, we determine the toxicity of EO and EO-based emulsion using dose-mortality curves and lethal times. Second, we subjected adult females of H. hampei to sublethal doses to assess whether they affected their behavior, reproductive output, and histological features. Our findings reveal that patchoulol (43.05%), α-Guaiene (16.06%), and α-Bulnesene (13.69%) were the main components of the EO. Furthermore, the EO and its emulsion had similar toxicity, with dose-mortality curves and lethal times overlapping 95% confidence intervals. We also observed that sublethal exposure of females of H. hampei reduces reproduction and feeding, increases walking activity, and causes histopathological changes in the midgut. This study advances the knowledge of sublethal effects of an eco-friendly substance on insects.

Influence of seasonal and climatic variables on coffee berry borer (Hypothenemus hampei Ferrari) flight activity in Hawaii

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.

Demography and perturbation analyses of the coffee berry borer Hypothenemus hampei (Coleoptera: Curculionidae): Implications for management

The coffee berry borer (CBB) Hypothenemus hampei Ferrari is the most serious pest of coffee worldwide. Management of the CBB is extremely difficult because its entire life cycle occurs inside the fruit, where it is well protected. Knowing which life stages contribute most to population growth, would shed light on the population dynamics of this pest and help to improve CBB management programs. Two staged-classified matrices were constructed for CBB populations reared in the lab on artificial diets and CBB populations from artificial infestations in the field. Matrices were used to determine demographic parameters, to conduct elasticity analyses, and to perform prospective perturbation analysis. Higher values of the intrinsic rate of natural increase (rm) and population growth rate (λ): were observed for CBB populations growing in the lab than in the field (rm: 0.058, λ: 1.74 lab; rm: 0.053, λ: 1.32 field). Sensitivity values for both CBB populations were highest for the transitions from larva to pupa (G2: 0.316 lab, 0.352 field), transition from pupa to juvenile (G3: 0.345 lab, 0.515 field) and survival of adult females (P5: 0.324 lab, 0.389 field); these three vital rates can be important targets for CBB management. Prospective perturbation analyses indicated that an effective management for the CBB should consider multiple developmental stages; perturbations of >90% for each transition are necessary to reduce λ to <1. However, when the three vital rates with highest sensitivity are impacted at the same time, the percentage of perturbation is reduced to 25% for each transition; with these reductions in survival of larvae, pupae and adult females the value of λ was reduced from 1.32 to 0.96. Management programs for CBB should be focused on the use of biological and cultural measures that are known to affect these three important targets.

Caracterización socioeconómica y fitosanitaria de 25 sistemas de producción de café (Coffea arábica L.) en tres municipios de Matagalpa, 2020

La producción de café en Nicaragua se encuentra en pequeños, medianos y grandes productores provenientes en su mayoría de la región norte central y noroeste del país. El objetivo de esta investigación fue caracterizar sistemas de café desde la perspectiva socioeconómica, agronómica (fitosanitario) y beneficiado húmedo (manejo de cosecha) mediante la ejecución de encuesta a caficultores. Basado en los resultados, se realizó análisis de datos. Los resultados obtenidos fueron los siguientes; el 84 % de los caficultores corresponden al sexo masculino, las edades están comprendidas en los 30 y 79 años, siendo los de 40 y 49 años los más representados (36 %). El 96 % de los productores, la tenencia de la tierra es propia. El Catimor (hibrido de timor x caturra) es la variedad más utilizada. Las principales plagas que inciden son nematodos fitoparásitos (Pratylenchus y Meloidogyne), gallina ciega (Phyllophaga spp.) y broca del café (Hypothenemus hampei), las enfermedades causadas por hongos, ojo de gallo (Mycena citricolor), roya (Hemileia vastatrix) y moho de hilachas (Pellicularia koleroga), las arvenses más reportadas por los productores, Ventanilla (Monstera adansoni) y Zacate estrella (Cynodon dactylon). El método de control más usado para, plagas insectiles, nematodos, enfermedades fungosas y arvenses, son los sintéticos. Gran parte de los productores no realizan análisis del café antes y después del beneficiado húmedo, ni limpieza de su medio de transporte al trasladar el café a centros de acopio.

Coffea arabica L. Resistant to Coffee Berry Borer (Hypothenemus hampei) Mediated by Expression of the Bacillus thuringiensis Cry10Aa Protein

Coffea spp. are tropical plants used for brewing beverages from roasted and grounded seeds, the favorite drink in the world. It is the most important commercial crop plant and the second most valuable international commodity after oil. Global coffee trade relies on two Coffea species: C. arabica L. (arabica coffee) comprising 60% and C. canephora (robusta) comprising the remaining 40%. Arabica coffee has lower productivity and better market price than robusta. Arabica coffee is threatened by disease (i.e., coffee leaf rust), pests [i.e., Hypothenemus hampei or coffee berry borer (CBB) and nematodes], and susceptibility to climate change (i.e., drought and aluminum toxicity). Plant biotechnology by means of tissue culture inducing somatic embryogenesis (SE) process, genetic transformation, and genome editing are tools that can help to solve, at least partially, these problems. This work is the continuation of a protocol developed for stable genetic transformation and successful plant regeneration of arabica coffee trees expressing the Bacillus thuringiensis (Bt) toxin Cry10Aa to induce CBB resistance. A highly SE line with a high rate of cell division and conversion to plants with 8-month plant regeneration period was produced. To validate this capability, gene expression analysis of master regulators of SE, such as BABY BOOM (BBM), FUS3, and LEC1, embryo development, such as EMB2757, and cell cycle progression, such as ETG1 and MCM4, were analyzed during induction and propagation of non-competent and highly competent embryogenic lines. The particle bombardment technique was used to generate stable transgenic lines after 3 months under selection using hygromycin as selectable marker, and 1 month in plant regeneration. Transgenic trees developed fruits after 2 years and demonstrated expression of the Bt toxin ranging from 3.25 to 13.88 μg/g fresh tissue. Bioassays with transgenic fruits on CBB first instar larvae and adults induced mortalities between 85 and 100% after 10 days. In addition, transgenic fruits showed a seed damage lower than 9% compared to 100% of control fruits and adult mortality. This is the first report on stable transformation and expression of the Cry10Aa protein in coffee plants with the potential to control CBB.

Coffee Berry Borer, Hypothenemus Hampei Ferr.: Cultural Control and In Vitro Effects of Kernel Extracts of Azadirachta indica A. Juss. and Thevetia peruviana (Pers.) Schum

The coffee berry borer, Hypothenemus hampei, is one of the most important coffee berry borer pests in the world, reaching attack rates of 10-100% in Cameroon. The objective of this study is to evaluate the efficacy of crop control and the effects of aqueous extracts of Thevetia peruviana kernel powder and aqueous extracts, and oil of Azadirachta indica kernel powder against this insect. Crop control was firstly achieved by sanitary harvesting of bark beetle-infested berries and, secondly, by the installation of a network of home-made pheromone traps. The bark beetles were breeding in the laboratory and tests were also carried out on substitute foodstuffs such as maize and groundnuts. The efficacy of pesticidal plant extracts at four concentrations each was evaluated by direct applications of these on bark beetles and berries. The results showed that the reproduction rate of the borer was 11 times higher with coffee berries than with maize and groundnuts. After the direct treatment of the bark beetles, the aqueous extracts of T. peruviana showed a significantly average efficiency on the mortality of the bark beetles ranging from 0% to 94.9% of bark beetles killed. Oil extracts of A. indica and chlorpyrifos-ethyl (Pyriforce) were more effective against bark beetles with average mortality rates ranging from 78.7 to 100%. After direct treatment of the berries, oil and aqueous extracts of A. indica and chlorpyrifos-ethyl were the most effective treatments causing more than 50% mortality of the bark beetles. Oil of A. indica and aqueous extracts of T. peruviana can therefore be used in the same way as pyriforce in the protection of coffee plants against H. hampei.

Seasonal phenology of Coffee Berry Borer (Hypothenemus hampei Ferrari) in Hawaii and the influence of weather on flight activity

Coffee berry borer (CBB, Hypothenemus hampei Ferrari) is the most serious insect pest of coffee worldwide, yet little is known about its seasonal flight behavior or the effect that weather variables have on its 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 influence of five weather variables on flight activity. 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 linear regression showed a moderate but significant negative relationship between elevation and total trap catch. A generalized additive mixed model (GAMM) revealed that mean daily air temperature has the most significant (positive) effect on CBB flight, with most flight events occurring between 20-26 °C. Mean daily solar radiation also had a significant positive effect, while maximum daily relative humidity negatively influenced flight at values above ˜94%. Flight was positively influenced by maximum daily wind speeds up to ˜2.5 m/s and cumulative rainfall up to 100 mm, after which activity declined. Our findings provide important insight into CBB flight patterns across a highly variable landscape and will serve as a starting point for the development of flight prediction models.

Bored Coffee Beans for Production of Hyaluronic Acid by Streptococcus zooepidemicus

Bored coffee beans (BCBs) are the residues left from the pest Hypothenemus hampei that attacks coffee crops, resulting in enormous economic losses. The bioconversion of monosaccharides from BCBs into hyaluronic acid (HA) is appealing both for using the residues and given the high commercial value of HA. This study dealt with the production of HA using Streptococcus zooepidemicus by employing either acid (AcH) or enzymatic (EnH) hydrolyzates from BCBs. The highest release of monosaccharides (evaluated using surface response methodology) was obtained with EnH (36.4 g/L); however, S. zooepidemicus produced more HA (1.5 g/L) using AcH compared to EnH. Hydrolyzates from acetone-extracted BCBs yielded 2.7 g/L of HA, which is similar to the amount obtained using a synthetic medium (2.8 g/L). This report demonstrates the potential of hydrolyzates from bored coffee beans to produce HA by S. zooepidemicus.

Structure and Dynamics of the Gut Bacterial Community Across the Developmental Stages of the Coffee Berry Borer, Hypothenemus hampei

The coffee berry borer (CBB); Hypothenemus hampei (Coleoptera: Curculionidae), is widely recognized as the major insect pest of coffee crops. Like many other arthropods, CBB harbors numerous bacteria species that may have important physiological roles in host nutrition, detoxification, immunity and protection. To date, the structure and dynamics of the gut-associated bacterial community across the CBB life cycle is not yet well understood. A better understanding of the complex relationship between CBB and its bacterial companions may provide new opportunities for insect control. In the current investigation, we analyzed the diversity and abundance of gut microbiota across the CBB developmental stages under field conditions by using high-throughput Illumina sequencing of the 16S ribosomal RNA gene. Overall, 15 bacterial phyla, 38 classes, 61 orders, 101 families and 177 genera were identified across all life stages, including egg, larva 1, larva 2, pupa, and adults (female and male). Proteobacteria and Firmicutes phyla dominated the microbiota along the entire insect life cycle. Among the 177 genera, the 10 most abundant were members of Ochrobactrum (15.1%), Pantoea (6.6%), Erwinia (5.7%), Lactobacillus (4.3%), Acinetobacter (3.4%), Stenotrophomonas (3.1%), Akkermansia (3.0%), Agrobacterium (2.9%), Curtobacterium (2.7%), and Clostridium (2.7%). We found that the overall bacterial composition is diverse, variable within each life stage and appears to vary across development. About 20% of the identified OTUs were shared across all life stages, from which 28 OTUs were consistently found in all life stage replicates. Among these OTUs there are members of genera Pantoea, Erwinia, Agrobacterium, Ochrobactrum, Pseudomonas, Acinetobacter, Brachybacterium, Sphingomonas and Methylobacterium, which can be considered as the gut-associated core microbiota of H. hampei. Our findings bring additional data to enrich the understanding of gut microbiota in CBB and its possible use for development of insect control strategies.