Method for maintenance of coffee leaves in vitro for mass rearing of Leucoptera coffeellum (Guérin-Méneville) (Lepidoptera: Lyonetiidae)

Kreslavsky V.D., Kobzar E.F., Muzafarov E.N.

Zarrabeitia A., Lejarcegui X., Veramendi J., Mingo-Castel A.M.

A medium containing low amounts of nitrogen (19–23 meq.l−1) produced optimum results in micropropagation as revealed by the number of nodes, internode length, chlorophyll content, and leaf area of four potato cvs. belonging each to four different maturity groups. Decreasing amounts of nitrogen also increased chlorophyll content in all four cultivars tested. The NH 4 + concentration did not have an effect on micropropagation for low nitrogen supplies. In all cvs., except Baraka, there was a “carry over” effect of the nitrogen content in the micropropagation medium onto subsequent tuberization, the lower nitrogen (23 meq.l−1) advancing tuber initiation. Microtuberization of cv. Jaerla was earlier in darkness than under short days regardless of the propagation medium used.

Bigger M.

(1969). Partial Resistance of Arabica Coffee to The Coffee Leaf Miner Leucoptera Meyricki Ghesq. (Lepidoptera, Lyonetiidae) East African Agricultural and Forestry Journal: Vol. 34, No. 4, pp. 441-445.

Altamiranda-Saavedra M., Camaho-Portocarrero R., Machado J.O., Jaramillo J.D., Torres-Moreno N., Marín-Ortiz J.C., Giraldo-Jaramillo M.

Insects of economic importance such as Leucoptera coffeella can cause high defoliation in plants and reduce crop yields. We aimed to identify changes in the ecological niche and potential zones of the invasion. Occurrence records were obtained from databases and bibliography. WorldClim V2.0 bioclimatic layers were used. For the modeling of the potential distribution, the kuenm R package was used by executing the Maxent algorithm. The potential distribution models suggested greatest environmental suitability extends from Europe, South Asia, and Central and South Africa, showing the “tropical and subtropical moist broadleaf forests” as the ecoregion that presents the greatest probability of the presence of L. coffeella. The potential distribution model projected in the invaded area agrees with the known distribution in the region (America), although the results show that it is occupying environmental spaces not present in the area of origin. This species presented a large proportion of the invaded niche that overlaps the native niche and is colonizing new environmental conditions in the invaded area relative to its native distribution (Africa). This information could be used in the planning of coffee crops on the American continent.

Santiago‐Salazar C.M., Barrera J.F., Rojas J.C., Huerta‐Palacios G., Escamilla‐Prado E.

The coffee leaf miner, Leucoptera coffeella (Guérin-Mèneville), is one of the main coffee pests (Coffea spp.) in the Neotropical region. This moth species develops exclusively on leaves of Coffea plants. In this study, we investigated the oviposition preference and performance of L. coffeella in environmentally stressed Coffea arabica L. plants. These plants were exposed to three independent treatments: (a) shade levels (0%, 50%, and 100%), (b) water availability (constant and intermittent irrigation), and (c) the application of phytohormones (salicylic acid, SA; or methyl jasmonate, MeJA). Groups of leaves from these treatments were exposed to individual L. coffeella-mated females, and the number of eggs laid per leaf and the performance in terms of the duration of the immature stages and survival of L. coffeella was recorded. Our results showed that oviposition preference was indistinct among the evaluated treatments. However, leaf miner larvae developed faster under 50% shade level, whereas survival was lower in plants under 100% shade level. Individuals reared on plants under 100% shade level showed slower larval development and smaller adult size. Constant plant irrigation decreased the L. coffeella survival. The application of MeJA delayed larval development, while the application of SA increased adult size. Our results suggest that plant environmental stress should be considered when studying the performance of specialist insect herbivores.

Rosado M.D., Araújo G.J., Pallini A., Venzon M.

• Cover crops provide plant-derived food to natural enemies of pests. • Buckwheat and sunn hemp increase coffee leaf miner predation and parasitism rate by wasps. • Predatory mites increase abundance on coffee plants intercropped with buckwheat and sunn hemp. • Cover crops promote biological control of phytophagous mites and have potential for coffee leaf miner control. Losses in coffee crops due to the pest attack harm up to 50% of production. In an attempt to control the progress of these herbivores, chemical inputs are used on crops, but with limited success and negative impact on biodiversity and on human health. We investigated in a field experiment whether cover crop intercropping with coffee would reduce coffee pest population by increasing natural enemy abundance. The cover crops Crotalaria juncea and Fagopyrum esculentum were selected based on agronomic traits and on the provision of food resources to natural enemies. They were tested in plots in a single cultivation and in mix combination intercropped with coffee. The control treatment was represented by coffee monoculture with bare soil. Predation rate of a key coffee pest, the coffee leaf miner Leucoptera coffeella , was higher in intercropped plots than in the monoculture. Increased parasitism rate of L. coffeella was found in plots intercropped with F. esculentum . However, during the experimental period, L. coffeella abundance was not affected by the cover crops. Phytophagous mites from Tetranychidae family were less abundant when coffee was intercropped with C. juncea . Their predators, Phytoseiidae mites, were more abundant on coffee intercropped with C. juncea and C. juncea plus F. esculentum . Diversification of coffee crops by intercropping with cover crops promotes biological control of phytophagous mites and shows potential for coffee leaf miner control. These results, together with the improvement of chemical, physical and biological characteristics of the soil and reduced weed competition, make cover crop intercropping a suitable strategy for coffee cultivation.

Santiago-Salazar C.M., Barrera J.F., Rojas J.C., Huerta-Palacios G., Escamilla-Prado E.

The coffee leaf miner, Leucoptera coffeella (Guérin-Méneville), is one of the main pests of coffee (Coffea spp.) in the Neotropical region. Leucoptera coffeella is considered a specialist insect because it develops exclusively within the leaves of the genus Coffea. In this laboratory study, we investigated the oviposition preference and performance of L. coffeella on the coffee leaf rust (Hemileia vastatrix Berkeley & Broome)-susceptible C. arabica cultivars “Red Catuai”, “Red Caturra”, and “Typica”, and resistant cultivars “Costa Rica 95”, “Oro Azteca”, and “IAPAR 59”. Individual (non-choice) and group (multiple-choice) leaves of these cultivars were exposed to mated individual L. coffeella females and the number of eggs laid per leaf was recorded. Oviposition preference was found to be indistinct among the coffee cultivars evaluated. However, larvae and pupal period, and adult body length were significantly affected by the coffee cultivar. These results are discussed in relation to the preference-performance hypothesis and its impact on L. coffeella’s strategy to choose the host plant.

Pantoja-Gomez L.M., Corrêa A.S., de Oliveira L.O., Guedes R.N.

The coffee leaf miner, Leucoptera coffeella (Guérin-Mèneville & Perrottet, 1842), probably infested coffee plants in Neotropical America during the 19th century. The species subsequently became a key pest of coffee plants in Brazil, but not in Colombia, the two main coffee producers in the region. The contrasting importance of the coffee leaf miner in Brazil and Colombia may be the result of the evolutionary and demographic history of this species. Therefore, our goal was to test two alternative hypotheses regarding the possible genetic origins of this species: 1) leaf miners in both countries share the same origin and 2) the leaf miner arrived in both countries independently from distinct sources and subsequently diversified without genetic exchange between countries. Thus, DNA sequence data of 21 populations were collected (Brazil, 16; Colombia, 5), and partial sequences of their cytochrome oxidase subunit I (COI), cytochrome b (Cytb), and the nuclear internal transcribed spacer (ITS) region were obtained to test these hypotheses. Both nuclear and mitochondrial molecular markers showed low nucleotide diversity. Analyses of molecular variance indicated higher variability within population in both concatenated mitochondrial genes and ITS region (70.57 and 84.01%, respectively). Finally, geno/haplotype networks showed each central geno/haplotypes that displayed high frequency and were distributed widely in both countries. Low-frequency geno/haplotypes were at tip positions connected to the central geno/haplotypes through single mutation steps, suggesting that the Neotropical coffee leaf miner in both Brazil and Colombia consists of a single species and exhibits a common and recent genetic origin.

Jordani M.X., Hasui É., da Silva V.X.

In recent decades, the consequences of habitat fragmentation have been of growing concern, because it is particularly important to understand how fragmentation may affect biodiversity, an ecological service. We tested two hypotheses: (1) that natural fragment size in agricultural landscapes indirectly affects the herbivore through effects on natural predator populations; and (2) predator activity into the crop reduces along the distance from the natural fragment edge. From 2008 and 2009, we conducted our study in seven forest remnants and in surrounding coffee plantations (fragments ranged from 6 to 105 ha, mean 49.28 ± 36.60 ha) in Southern Minas Gerais, Brazil. Birds were sampled by point counts, and insect predation was evaluated by using an artificial insect model (Koh and Menge 2006). Our results suggest that although there were many potential predators (e.g., wasps, ants, birds, and mammals), birds were the most important taxon unit. The covariance analysis supported the hypothesis that patch size affected the number of larvae predation by overall taxi, but there was no support for a distance effect. These findings suggest that natural enemies’ ecological service (mainly from birds) declined with remnant reduction, which has implications not only for human welfare, but also in strengthening the economic justifications for conserving the remaining natural habitats and biodiversity in agricultural landscapes.

Nascimento J.B., Barrigossi J.A., Borba T.C., Martins J.F., Fernandes P.M., Mello R.N.

This study aimed to observe the response of 34 rice accessions to attack by sugarcane borer (Diatraea saccharalis Fabr., 1794) and to analyze the genetic diversity of these accessions by microsatellite markers. Twenty larvae were placed on the leaf sheaths of rice plants. At 30 days after infestation the rice plants at ground level were taken to the laboratory where the signs of borer attack, external and internal diameter of the stem and weight of surviving larvae were determined. For the molecular analysis of rice accessions, 24 microsatellite markers were used. The results of the morphological traits of the rice plant, response of the plant to insect attack, development of the sugarcane borer larvae and molecular data, indicated a genotypic variation. The accessions that most favored larval survival were IAC 47 and Ti Ho Hung. Larvae with highest weight (0.0986 g and 0.0862 g) and the largest internal diameters of the rice stem (3.18 mm) were found in land races “Canela de Ferro” (rust colored stem) and all these “Canela de Ferro” accessions also remained genetically grouped. The most tolerant materials, based on the ability to produce new tillers after larval infestation were, Chiang an Tsao Pai Ku and IR 40 which remained morphological and genetically grouped. The results of this study indicate that all the traits and molecular analyses were able to separate the accessions of rice into different groups in relation to resistance to the sugarcane borer. These materials can be used as donor sources in breeding for genetic resistance to sugarcane borers and can be used as donors to amplify the genetic base of Brazilian rice.

Nascimento J.B., Barrigossi J.A.

Semeão A.A., Martins J.C., Picanço M.C., Chediak M., da Silva E.M., Silva G.A.

AbstractIt is important to understand how components of the agroecosystem interfere with the attack of a pest species and their seasonality in order to use these components in IPM programs. This study focused on the evaluation of the seasonality of natural control factors associated with the guava psyllid Triozoida limbata (Enderlein) in Brazil. Life-table data were collected from an experimental guava orchard during four periods that roughly represented four seasons. Natural mortality was monitored daily through the immature stages, and the relative importance of each natural mortality factor and its seasonality was determined. Significant statistical differences were observed in the mortality during the four periods (P < 0.05). Several factors contributed to the mortality of T. limbata, including rainfall, physiological disturbance, the parasitoid Psyllaephagus sp. (Hymenoptera: Encyrtidae) and specific predators: syrphids, predatory wasps and other generalist predators. Depending on the location of nymphs (exposed or inside galls), the relative importance of the different natural mortality factors changed. The principal component analysis (PCA) showed some trends in the relationship of natural control agents and weather conditions. For example, the occurrence of predatory wasps was positively correlated with temperature and occurrence of winds; the occurrence of syrphids and Psyllaephagus sp. were negatively correlated with temperature and winds; and the occurrence of other generalist predators were negatively correlated with the occurrence of rainfall and photoperiod. The results showed the importance of natural mortality factors for the management of T. limbata and their changes through the different seasons which should be considered when implementing IPM programs in guava orchards.

Alves D.S., Oliveira D.F., Carvalho G.A., Santos M.A.

Objetivou-se, com o presente trabalho, verificar o efeito do extrato metanólico de Coffea racemosa Lour., espécie silvestre de cafeeiro portadora de resistência a uma das principais pragas da cultura cafeeira, o bicho-mineiro. Inicialmente, o extrato metanólico das folhas de C. racemosa foi pulverizado em mudas de cafeeiro Coffea arabica cv. Catuaí, em casa-de-vegetação, as quais foram expostas a adultos de L. coffeella para o teste de oviposição com chance de escolha. Observou-se que as plantas tratadas foram menos preferidas para oviposição. A seguir, realizou-se o teste de efeito ovicida, no qual mudas de C. arabica contendo ovos do bicho-mineiro foram pulverizadas com o mesmo extrato. Os experimentos foram conduzidos em delineamento inteiramente casualizado com cinco repetições. Verificou-se redução significativa na eclosão de larvas, e segundo análise por microscopia eletrônica de varredura, os ovos não viáveis apresentaram anomalias nas superfícies externas. Entretanto, os adultos provenientes de ovos tratados não foram afetados na percentagem de emergência, razão sexual e oviposição. Os resultados obtidos demonstram que C. racemosa apresenta-se como uma alternativa promissora ao controle do bicho-mineiro, necessitando, no entanto, de novos estudos para isolamento e identificação das substâncias bioativas.

Lomelí-Flores J.R., Barrera J.F., Bernal J.S.

We assessed the influences of ambient temperature, rainfall, shade cover and elevation on seasonal abundance of coffee leafminer Leucoptera coffeella (Guerin-Meneville) and its natural enemies in coffee farms in the Soconusco region of Chiapas, Mexico. Mined coffee leaves were most abundant during the rainy season (i.e. historical average rainfall >200 mm/mo, April–November) compared to the dry season ( 900 m asl) elevations. The abundance of mined leaves increased with rainfall, and decreased with maximum daily temperatures. Coffee leafminer survivorship was highest during the dry season (>40%), when predation was lowest ( 25%) when coffee leafminer incidence was highest (>30% mined leaves per plant). None of the weather variables that were evaluated (viz. maximum and minimum temperatures, and rainfall) significantly impacted parasitism ratios. Shade cover moderated on-farm temperatures, by reducing maximum daily temperatures and any potential, direct impacts of rainfall on coffee leafminer, by providing partial shelter from rainfall, but did not significantly affect coffee leafminer incidence. In 48 h laboratory trials, coffee leafminer oviposition was highest at 28 °C (∼15 eggs/female), minimal at 25 °C (∼3 eggs) and nil at 20 °C, and higher during night-time hours (>8 eggs/female/day) compared to day-time hours (  20 °C) were permissive of coffee leafminer oviposition during twice as many hours each year at low elevation (4060 h) compared to high elevation (2081 h). Overall, our results suggested that evident differences in the abundance of coffee leafminer between elevations may be due in considerable part to differences in ambient temperatures, particularly night-time temperatures, rather than rainfall, shade cover, or elevation per se.

Magalhães S.T., Fernandes F.L., Demuner A.J., Picanço M.C., Guedes R.N.

Coffee (Coffea spp.) alkaloids (caffeine and related methylxanthines) and phenolics (caffeic and chlorogenic acids) have recognized pestistatic/pesticidal activity and mediate insect-plant interactions. The present investigation assessed the resistance of 12 coffee genotypes to the leaf miner Leucoptera (= Perileucoptera) coffeella (Guérin-Méneville & Perrottet) (Lepidoptera: Lyonetiidae) and correlated such results with the leaf content of coffee alkaloids and phenolics that probably play a role in the interaction between coffee and this leaf miner. The levels of chlorogenic and caffeic acid, caffeine, and related methylxanthines were measured and quantified in leaf extracts of these genotypes before and 7 d after their infestation by the leaf miner. Some coffee genotypes (Coffea canephora L. and Coffea racemosa Lour. and its hybrids with Coffea arabica L.) exhibited high pesticidal activity (100% mortality) toward the L. coffeella, indicating their antibiosis resistance. However, there was no correlation between this activity and the leaf levels of coffee alkaloids and phenolics. Curiously, infestation by L. coffeella leads to a nearly four-fold decline in the leaf levels of chlorogenic acid, which does not affect this pest species but may affect other generalist species. Indeed, chlorogenic acid sprayed on coffee leaves stimulated locomotory activity of the green scale Coccus viridis (Green) (Hemiptera: Coccidae), thus minimizing their feeding in contrast with the absence of this polyphenol. Therefore, reduction of chlorogenic acid levels in coffee leaves due to leaf miner infestation seems to also favor infestation by generalist insects, such as the green scale.

Malo E.A., Rojas J.C., Lopez-Guillen G.

Lomeli-Flores J.R., Barrera J.F., Bernal J.S.

Coffee leafminer, Leucoptera coffeella, is a pest in many New World coffee growing areas. Previous studies suggested that its population dynamics were strongly affected by natural enemies, particularly of larvae, and physical environmental conditions. Our study documented through field surveys and life table analyses (i) the natural enemy complex associated with coffee leafminer and (ii) the impacts of natural enemies on the population dynamics of coffee leafminer, on coffee (Coffea arabica) at two elevations and two rainfall levels in the Soconusco region of Chiapas, Mexico. Twenty-two larval parasitoid species (including 14 morphospecies) were collected. Egg and pupal parasitoids were not recovered. Life table analyses showed that parasitism contributed ⩽10% of real mortality, and parasitism rates were 8–10-fold higher at the low ( 950 m) elevation; parasitism rates were similar under low ( 400 mm) rainfall. Seventeen predator species (including five morphospecies) were collected, of which most were ants (Formicidae, 14 species) that contributed >58% of real mortality. Life table analyses showed that predation rates were higher at high versus low elevation and under high versus low rainfall. Independently of elevation and rainfall, egg predation (likely by ants) was the most important source of indispensable mortality (range = 0.13–0.30), except at low elevation and high rainfall where pupal predation (=0.14) was similarly important. Also, predation was the main source of coffee leafminer larval and pupal mortality during a 13-month period in a low elevation coffee farm and was highest during the rainy season (>400 mm rainfall/month), when coffee leafminer prevalence was highest. Overall, predation of eggs and pupae (the latter particularly at low elevation), mostly by ants, were the most important sources of coffee leafminer mortality. Because ants were the main source of coffee leafminer egg and pupal mortality, their importance and potential role in coffee pest management strategies were discussed.

Magalhães S.T., Guedes R.N., Demuner A.J., Lima E.R.

AbstractThe 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.