Sampling plan for the coffee leaf miner Leucoptera coffeella with sex pheromone traps

The population density of the coffee leaf miner Leucoptera coffeella (Guérin-Méneville & Perrottet) (Lep., Lyonetiidae) can be estimated using pheromone traps in coffee fields as male capture reflects this pest damage based on previous correlational study. However, the spatial distribution of pheromone traps and their density are necessary to optimize the sampling procedure with pheromone traps. Therefore, the objectives of the present study were to determine the pheromone trap density required per hectare to sample coffee leaf miner populations and to determine the spatial distribution of the males of this pest species. The males were sampled every 8 days in 12 consecutive evaluations. Taylor's power law and frequency distributions were used to recognize the distribution of the male capture data, which followed a negative binomial distribution. A common K was obtained, allowing the establishment of a single conventional sampling plan for the 12 fields investigated. The adjusted sampling plan requires eight traps in an area of 30 ha for a 25% precision error. Kriging-generated maps allowed the simulation of male captures for 8, 12 and 20 traps per 30 ha and the results were compared with those obtained with absolute sampling resulting in R ²-values of 0.30, 0.57 and 0.60 respectively. The traps were able to identify the more highly infested areas within the field and are a precise and efficient tool for sampling populations of L. coffeella.     

Effect of coffee alkaloids and phenolics on egg-laying by the coffee leaf miner Leucoptera coffeella

The recognized importance of coffee alkaloids and phenolics mediating insect-plant interactions led to the present investigation aiming to test the hypothesis that the phenolics chlorogenic and caffeic acids and the alkaloid caffeine and some of its derivatives present in coffee leaves affect egg-laying by the coffee leaf miner Leucoptera (=Perileucoptera) coffeella (Guérin-Méneville & Perrottet) (Lepidoptera: Lyonetiidae), one of the main coffee pests in the Neotropical region. These phytochemicals were, therefore, quantified in leaves from 12 coffee genotypes and their effect on the egg-laying preference by the coffee leaf miner was assessed. Canonical variate analysis and partial canonical correlation provided evidence that increased leaf levels of caffeine favour egg-laying by the coffee leaf miner. An egg-laying preference bioassay was, therefore, carried out to specifically test this hypothesis using increasing caffeine concentrations sprayed on leaves of one of the coffee genotypes with the lowest level of this compound (i.e. Hybrid UFV 557-04 generated from a cross between Coffea racemosa Lour. and C. arabica L.). The results obtained allowed the recognition of a significant concentration-response relationship, providing support for the hypothesis that caffeine stimulates egg-laying by the coffee leaf miner in coffee leaves.     

Optimum spacing of pheromone traps for monitoring the coffee leaf miner Leucoptera coffeella

Pest monitoring with pheromone traps is affected mainly by factors such as trap placement and pest biology. The intertrap distance can affect the capture due to competition among traps that are placed at short distances. We studied the interference among pheromone traps used to monitor males of the coffee leaf miner, Leucoptera coffeella (Guérin‐Méneville) (Lepidoptera: Lyonetiidae), with traps placed at various distances. Using geostatistical analysis, we determined at what distance captures were independent from other traps. Traps were placed in groups of 12 with distances among traps per group either 2, 5, 10, 15, or 30 m. Traps were checked for males every 4 days during 16 days. We found interference between traps when intertrap distances were shorter than 10 m. The range and magnitude of spatial dependence varied considerably among each sampling date and wind direction. For directions of 45° and 135°, the traps should be placed 110 and 177 m apart, respectively, to obtain spatially independent counts and therefore representative samplings for assessing the insect population in the area. These results have implications for developing sampling plans for managing L. coffeella with pheromone traps; the spatial analysis indicated that a trap density of one pheromone trap for every 3.5–4 ha would be adequate for the monitoring of the coffee leaf miner.     

Insecticide use and organophosphate resistance in the coffee leaf miner Leucoptera coffeella (Lepidoptera: Lyonetiidae)

Increasing rates of insecticide use against the coffee leaf minerLeucoptera coffeella(Guérin-Méneville) and field reports on insecticide resistance led to an investigation of the possible occurrence of resistance of this species to some of the oldest insecticides used against it in Brazil: chlorpyrifos, disulfoton, ethion and methyl parathion. Insect populations were collected from ten sites in the state of Minas Gerais, Brazil and these populations were subjected to discriminating concentrations established from insecticide LC99s estimated for a susceptible standard population. Eight of the field-collected populations showed resistance to disulfoton, five showed resistance to ethion, four showed resistance to methyl parathion, and one showed resistance to chlorpyrifos. The frequency of resistant individuals in each population ranged from 10 to 93% for disulfoton, 53 to 75% for ethion, 23 to 76% for methyl parathion, and the frequency of resistant individuals in the chlorpyrifos resistant population was 35%. A higher frequency of individuals resistant to chlorpyrifos, disulfoton and ethion was associated with greater use of insecticides, especially other organophosphates. This finding suggests that cross-selection, mainly between organophosphates, played a major role in the evolution of insecticide resistance in Brazilian populations of L. coffeella. Results from insecticide bioassays with synergists (diethyl maleate, piperonyl butoxide and triphenyl phosphate) suggested that cytochrome P450-dependent monooxygenases may play a major role in resistance with minor involvement of esterases and glutathione S-transferases.     

Effectiveness of acibenzolar-S-methyl, fungicides and antibiotics for the control of brown eye spot, bacterial blight, brown leaf spot and coffee rust in coffee

This study was carried out to evaluate the potential of acibenzolar‐S‐methyl (ASM), combined or not combined with fungicides and antibiotics for the control of brown eye spot (Cercospora coffeicola) and bacterial blight (Pseudomonas syringae pv. garcae) in coffee seedlings, and ASM combined with conventional fungicide application schedules for the control of coffee rust (Hemileia vastatrix) and brown leaf spot (Phoma costarricencis) under field conditions in two coffee crops in the State of São Paulo, Brazil. ASM protected coffee seedlings against C. coffeicola when applied at the rates of 2.5 and 5 g of active ingredient per hectolitre of water (g a.i. hL^?1), providing 34–55% of disease control, and against bacterial blight, when applied at the rates of 2.5, 10 and 20 g a.i. hL^?1, with 38–57% of disease control. Tebuconazole (100 g a.i. hL^?1) and azoxystrobin (10 g a.i. hL^?1) showed the best results for brown eye spot control. Oxytetracycline + streptomycin, kasugamycin hydrochloride, oxytetracycline + metallic copper, copper oxychloride and mancozeb + copper oxychloride also controlled bacterial blight in levels similar to those shown by ASM. In the field experiments, all fungicide application schedules tested, cyproconazole (December, February, April), epoxiconazole (December, March), tetraconazole (December, February, April), cyproconazole (December, February) and azoxystrobin (January, March) were effective for coffee rust control and provided partial control of brown leaf spot. The results also showed that for all experiments, there was no synergistic effect of the combination of ASM with azoxystrobin, cyproconazole or cupric fungicides.     

Polyphenoloxidase activity in coffee leaves and its role in resistance against the coffee leaf miner and coffee leaf rust

In plants, PPO has been related to defense mechanism against pathogens and insects and this role was investigated in coffee trees regarding resistance against a leaf miner and coffee leaf rust disease. PPO activity was evaluated in different genotypes and in relation to methyl-jasmonate (Meja) treatment and mechanical damage. Evaluations were also performed using compatible and incompatible interactions of coffee with the fungus Hemileia vastatrix (causal agent of the leaf orange rust disease) and the insect Leucoptera coffeella (coffee leaf miner). The constitutive level of PPO activity observed for the 15 genotypes ranged from 3.8 to 88 units of activity/mg protein. However, no direct relationship was found with resistance of coffee to the fungus or insect. Chlorogenic acid (5-caffeoylquinic acid), the best substrate for coffee leaf PPO, was not related to resistance, suggesting that oxidation of other phenolics by PPO might play a role, as indicated by HPLC profiles. Mechanical damage, Meja treatment, H. vastatrix fungus inoculation and L. coffeella infestation caused different responses in PPO activity. These results suggest that coffee resistance may be related to the oxidative potential of the tissue regarding the phenolic composition rather than simply to a higher PPO activity.     

三种酰胺类新农药对水稻孕穗期稻纵卷叶螟的防效试验

单季杂交晚稻孕穗期稻纵卷叶螟Cnaphalocrocis medinalis Guenée发生不整齐,为害重,在主治药剂氟虫腈即将禁用之际,急需防治高龄幼虫的长效药剂,酰胺类农药是满足这一条件的新一代农药。3种酰胺类农药试验结果,在单季稻孕穗期防治稻纵卷叶螟,20%氟虫双酰胺(WDG)150g/hm2处理速效性与持效性表现最好,药后3d防效达90.3%,药后15d防效高达96.2%;20%氯虫苯甲酰胺(SC)150mL/hm2处理速效性略低于氟虫双酰胺,持效接近,药后3d、15d防效分别达75.2%、91.2%;40%氯虫·噻虫嗪(WDG)120mL/hm2处理速效介于氟虫双酰胺和氯虫苯甲酰胺之间,持效略低于前二者,药后3d、15d防效分别为83.2%、88.3%。对照药剂5%氟虫腈(SC)750mL/hm2和90%杀虫单3000g/hm2处理药后3d、15d的防效均低于上述3种酰胺类新药剂。保叶效果以氯虫苯甲酰胺、氟虫双酰胺处理最高,药后15d保叶率分别为83.6%和85.0%,二者无显著差异,其次为氯虫·噻虫嗪处理为59.6%,3种酰胺类新药剂保叶效果均显著高于对照药剂氟虫腈和杀虫单。结果表明,3种酰胺类农药孕穗期防治稻纵卷叶螟的药效、持效性和保叶效果均高于当前主治药剂氟虫腈、杀虫单,可在生产上推广应用。     

Genetically modified coffee plants expressing the Bacillus thuringiensis cry1Ac gene for resistance to leaf miner

 A synthetic version of the cry1Ac gene of Bacillus thuringiensis has been used for the transformation of coffee species (Coffea canephora and C. arabica) to confer resistance to an important pest, the coffee leaf miner (Perileucoptera coffeella and other Leucoptera spp). Somatic embryos were co-cultivated with the LBA4404 strain of Agrobacterium tumefaciens containing the cry1Ac gene. More than 100 transformed plants from independent transformation events were obtained for each coffee genotype. The integration and expression of the cry1Ac gene was studied, and effective resistance of transgenic plants against leaf miner was verified in bioassays with the insects. These plants could represent a good opportunity to analyse the impact of genetic engineering of perennial crops for sustainable resistance to an obligate endocarpic pest using a B. thuringiensis insecticidal protein. Received: 7April 1999 / Revision received: 20 July 1999 / Accepted: 22 July 1999     

Synthesis of all four possible stereoisomers of 5,9-dimethylpentadecane, the major sex pheromone component of the coffee leaf miner moth, Perileucoptera coffeella

All of the four possible stereoisomers of 5,9-dimethylpentadecane, the major sex pheromone component of the coffee leaf miner moth (Perileucoptera coffeella), were synthesized by using the methyl esters of (S)- and (R)-3-hydroxy-2-methylpropanoic acid as chiral sources for the purpose of determining the stereochemistry of the pheromone.     

Twig-Nesting Ants: The Hidden Predators of the Coffee Berry Borer in Chiapas,Mexico

Coffee is a globally important crop that is subject to numerous pest problems, many of which are partially controlled by predatory ants. Yet several studies have proposed that these ecosystem services may be reduced where agricultural systems are more intensively managed. Here we investigate the predatory ability of twig-nesting ants on the main pest of coffee, the coffee berry borer (Hypothenemus hampei) under different management systems in southwest Chiapas, Mexico. We conducted both laboratory and field experiments to examine which twig-nesting ant species, if any, can prey on free-living borers or can remove borers embedded in coffee fruits and whether the effects of the twig-nesting ant community differ with habitat type. Results indicate that several species of twig-nesting ants are effective predators of both free-living borers and those embedded in coffee fruits. In the lab, Pseudomyrmex ejectus, Pseudomyrmex simplex, and Pseudomyrmex PSW-53 effectively removed free-living and embedded borers. In the field, abundance, but not diversity, of twig-nesting ant colonies was influenced by shade management techniques, with the highest colony abundance present in the sites where shade trees were recently pruned. However, borer removal rates in the field were significant only in the shadiest site, but not in more intensively managed sites. This study provides evidence that twig-nesting ants can act as predators of the coffee berry borer and that the presence of twig-nesting ants may not be strongly linked to shade management intensity, as has been suggested for other arthropod predators of the borer.     

Conflict between optimal clutch size for mothers and offspring in the leaf miner, Leucoptera sinuella

Abstract. 1. Clutch size in a leaf‐mining moth, Leucoptera sinuella (Reutti), was examined to determine whether the clutch size in natural populations meets the prediction of an optimal strategy, through comparisons between the optimal clutch sizes for offspring and for a mother. 2. A field experiment revealed that premature leaf abscission, egg dropping, and larval competition were important selective forces in determining the clutch size of this leaf miner on its host plant, Salix miyabeana. Then, optimal clutch size was predicted using the theoretical model of Weis et al. (1983 ), from the data obtained in the field experiment. 3. The model predicts that the clutch size that maximises offspring fitness is two, and that the clutch size that maximises reproductive success of the female varies from two to four, depending on the female's survival rate between oviposition events. The predicted clutch size (two) was identical to the clutch size observed most frequently in the field, assuming > 95% survival rate of females. Suitability of the model of Weis et al. (1983 ) was discussed based on these results.     

Wild coffee management and plant diversity in the montane rainforest of southwestern Ethiopia

Coffea arabica occurs naturally in the montane rainforests of Ethiopia, but large areas of these unique forests have been converted to other land-uses. In the remaining forest, wild coffee is managed and harvested with increasing intensity because of rising coffee prices in the world market. This study evaluated the impact of coffee management on wild coffee populations and the forest vegetation as a basis for conservation planning in southwestern Ethiopia. Vegetation surveys and yield assessments were carried out in unmanaged natural forest and in managed semi-forest coffee (SFC) systems. Analyses show that wild coffee density and coffee yields were low in natural forest (max. 15 kg ha⁻¹ year⁻¹). In SFC systems, 30% of the canopy trees and most undergrowth vegetation were removed. This stimulated wild coffee growth and strongly enhanced yields (max. 54 kg ha⁻¹ year⁻¹), but severely disturbed forest structure. Species richness increased by 26% because of an increase in species of ruderal and secondary vegetation; however, species richness and abundance of typical forest species declined. Conservation of the natural forest therefore requires the control of wild coffee management. Wild coffee certification is discussed as one tool to reconcile conservation measures and the interests of local farmers.     

氨基甲酸酯杀虫剂灭蚜威及其与阿维菌素的混配制剂对美洲斑潜蝇的防治效果

田间试验表明 ,氨基甲酸酯新杀虫剂灭蚜威单剂与生物农药阿维菌素混剂对美洲斑潜蝇Liro myzasativae防治效果优良。 5 0 %灭蚜威可湿粉使用剂量 2 5g(a .i.) 667m2 的 3～ 1 1d校正防效为85 2 8%～ 86 3 9% ,1 8 75g(a.i.) 667m2 相应药效为 83 0 1 %～ 84 0 4%。 3种不同配比的灭蚜威与阿维菌素混剂使用剂量 1 0g(a .i.) 667m2 ,药后 3～ 1 1d防效为 85 90 %～ 90 3 3 % ,7 5g(a .i.) 667m2 相应药效为 83 48%～ 88 5 2 %。     

Pollen types from colonies of Melipona scutellaris Latreille, 1811 (Hymenoptera: Apidae) established in a coffee plantation

Melipona scutellaris is a eusocial bee with potential to be used as a crop pollinator. This study aimed to identify pollen types used by Melipona scutellaris through the analysis of pollen loads and honey samples in colonies established in a coffee plantation. We analysed 117 pollen loads and pollen content of 15 honey samples. In the pollen loads, we identified 40 pollen types. Poincianella pyramidalis, Coffea arabica, Commelina villosa, Mimosa tenuiflora, Myrcia, Senna macranthera, Solanum and Syagrus coronata stood out as predominant pollen. We found a negative correlation between the abundances of the pollen types Coffea arabica and Mimosa tenuiflora during coffee flowering. In the honey samples, we recorded 33 pollen types. Eucalyptus and Machaerium occurred in frequencies of between 16 and 45%. Although Melipona scutellaris gathers resources from several plant species, its diet is based on a relatively narrow subset of plants.     

Abundance of Coffee berry borer in feral,abandoned and managed coffee on Hawaii Island

Coffee berry borer (Hypothenemus hampei Ferrari), the most damaging insect pest of coffee worldwide, was first detected on Hawaii Island in 2010. Poorly managed, abandoned and feral coffee sites on the island have since been thought to harbour coffee berry borer (CBB) populations, which then negatively impact neighbouring coffee farms. In the present study, we sought to quantify CBB abundance in these sites, which vary in management intensity and vegetation structure and diversity. We collected data on trap catch as a measure of CBB flight activity, fruit production and fruit infestation by CBB in eight well-managed farms and sites that were either poorly managed, abandoned or feral (wild) coffee. Sites were sampled bi-weekly over a period of 2 years from 2016 to 2017. We found that CBB flight activity was significantly higher in poorly managed sites relative to abandoned and feral sites, but was not significantly different from well-managed sites. Coffee production in well-managed farms was significantly higher than in abandoned and feral sites, but was not significantly different from poorly managed farms. CBB infestation in poorly managed sites was significantly higher than that observed in well-managed, abandoned and feral sites. We estimated an average load of 11–25 CBB per branch at poorly managed sites, compared to 3–9 per branch at well-managed sites, 1–16 per branch at abandoned sites and 1–3 per branch at feral sites. Our findings suggest that poorly managed sites should be prioritized for implementation of CBB control measures as part of a landscape-level integrated pest management (IPM) programme.     

Reaction of Some Coffea arabica Genotypes to Strains of Colletotrichum kahawae, the Cause of Coffee Berry Disease

Pathogenicity tests were performed on 11 genotypes of Coffea arabica using single‐isolate suspensions of Colletotrichum Kahawae obtained from 90 monoconidial isolates. The objective of this study was to estimate the proportion of pathogenic variation corresponding 10 differences in aggressiveness and virulence (races). A large part of the variation in the pathogen population was due to aggressiveness. The differential effects were too small to suggest conclusively that races exist. This paper discusses the possible causes for the observed small differential interaction and suggests breeding strategies that not only prevent possible adaptation of the pathogen to resistant varieties but also limit variation for resistance due to differences in aggressiveness of the pathogen.     

In field-grown coffee trees source-sink manipulation alters photosynthetic rates, independently of carbon metabolism, via alterations in stomatal function

Perturbations of the source-sink balances were performed in field-grown coffee (Coffea arabica) trees to investigate the possible role of carbohydrates in feedback regulation of photosynthesis. Four treatments were applied at the whole-plant level: (i) complete defruiting and maintenance of the full leaf area, (ii) the half crop load and full leaf area, (iii) the full crop load and full leaf area and (iv) the full crop load and half leaf area. Sampling and measurements were performed twice during the phase of dry matter accumulation of fruits. Gas exchange, chlorophyll a fluorescence, carbon isotope labelling and steady-state metabolite measurements were assessed in source leaves. The average rate of net photosynthetic rate (A) and stomatal conductance (g(s)) were larger (> 50%), and carbon isotope composition ratio was lower, in trees with a full crop load and half leaf area than in defruited trees, with individuals of the other two treatments showing intermediate values. However, differences in A seem unlikely to have been caused either by photochemical impairments or a direct end-product-mediated feedback down-regulation of photosynthesis. It is proposed that the decreased A in defruited coffee trees was independent of carbon metabolism and was rather directly related to a lower CO(2) availability coupled to lower g(s).     

Foliar fertilizers for the management of phoma leaf spot on coffee seedlings

The growing demand for alternative strategies for plant disease management has sought a reduction in the use of fungicides via the employment of resistance inducers and foliar fertilizers, among others. Therefore, this study aimed at evaluating the following foliar fertilizers for the management of phoma leaf spot: a foliar fertilizer based on macro‐ and micronutrients (Fmm: 10% N, 4% S, B, 5% Fe and 5% Zn); one based on cobalt and molybdenum (Fcm: 2% Co and 3% Mo); manganese phosphite (FMn: 30% P₂O₅ and 9% Mn); and the FMn+Fmm, Fcm+Fmm and FMn+Fcm+Fmm associations compared to a boscalid fungicide and a control with no treatment. The disease severity, the chlorophyll a and b contents, the net photosynthetic rate (LPR), the phenylalanine ammonia lyase (PAL) activity and the lignin content in leaves were assessment. Based on the severity, the area under the disease severity progress curve (AUSPC) and the efficiency of disease control in relation to untreated plants were calculated. The experimental design was in randomized blocks with eight treatments and three replications. Treatments FMn+Fmm and Fcm were the most effective in reducing the AUPSC in comparison with the control and promoted an increased activity of PAL. FMn was the treatment that promoted the highest increase in the LPR. There were no effects of the treatments on the lignin content compared to the control.     

北京地区西花蓟马田间种群的抗药性监测

采用叶管药膜法在室内测定了2009—2010年北京海淀地区和昌平地区西花蓟马Frankliniella occidentalis(Pergande)田间种群对12种杀虫剂敏感性的年度变化。结果表明,北京昌平和海淀地区的西花蓟马对多数的药剂仍处于敏感状态,但对氯氟氰菊酯已产生近40倍的抗性,昌平种群对多杀菌素具有产生低水平抗性的趋势(抗性倍数为4倍)。推荐药剂包括多杀菌素、阿维菌素、甲氨基阿维菌素苯甲酸盐(甲维盐)、毒死蜱和溴虫腈,应注意与其它药剂的轮换使用,灭多威对西花蓟马的毒力水平最低,不推荐使用。