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R N C Guedes - One of the best experts on this subject based on the ideXlab platform.

  • common origin of brazilian and colombian populations of the neotropical coffee Leaf Miner leucoptera coffeella lepidoptera lyonetiidae
    Journal of Economic Entomology, 2019
    Co-Authors: Laura M Pantojagomez, Alberto S Correa, Luiz Orlando De Oliveira, R N C Guedes
    Abstract:

    The coffee Leaf Miner, Leucoptera coffeella (Guerin-Meneville & 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.

  • insecticide toxicity and walking response of three pirate bug predators of the tomato Leaf Miner tuta absoluta
    Agricultural and Forest Entomology, 2014
    Co-Authors: Renata Ramos Pereira, Marcelo Coutinho Picanco, Paulo A Santana, Suzana S Moreira, R N C Guedes, Alberto S Correa
    Abstract:

    The tomato Leaf Miner Tuta absoluta is a key pest of the tomato and is of global significance. Insecticide is the primary method for controlling this pest, requiring a search for compounds with a low toxicity to nontarget organisms. We assessed the toxicity of eight insecticides to T. absoluta and its pirate bug predators Orius tristicolor, Amphiareus constrictus and Blaptostethus pallescens (Hemiptera: Heteroptera: Anthocoridae). We also assessed the effect of insecticide synergists on their toxicity to the predators, as well as their walking response to insecticide exposure. All insecticides, with the exception of methamidophos, exhibited the minimum efficacy threshold required by the Brazilian legislation (80% efficacy) at concentrations lower than the registered label rates. Indoxacarb and chlorantraniliprole exhibited a lower toxicity to the pirate bug predators than to the tomato Leaf Miner. The results obtained with the synergized insecticides suggest the involvement of cytochrome P450-dependent monooxygenases as the primary detoxification enzymes minimizing insecticide toxicity in the pirate bug predators. The insecticides led to a reduction in predator walking activity, especially abamectin and indoxacarb, which significantly minimized predator exposure. The results of the present study indicate that novel insecticides, especially chlorantraniliprole, are better suited to sustainable integrated management programmes of the tomato Leaf Miner.

  • spatial and temporal variation in the control failure likelihood of the tomato Leaf Miner tuta absoluta
    Annals of Applied Biology, 2013
    Co-Authors: Pablo Costa Gontijo, Marcelo Coutinho Picanco, E J G Pereira, Julio Claudio Martins, Mateus Chediak, R N C Guedes
    Abstract:

    Insecticide resistance is frequently associated with field control failure, but such an assessment of its likelihood seldom occurs. This phenomenon is a potential cause of the control failure of the tomato Leaf Miner Tuta absoluta (Lepidoptera: Gelechiidae); therefore we surveyed insecticide resistance as the control failure likelihood for a duration of 7 years in 20 field populations of this species. The insecticide label rate was used as the discriminating concentration, and the minimum efficacy threshold required for insecticides in Brazil (i.e. 80% efficacy) was the targeted efficacy. The spatial and temporal variations of the control failure likelihood were also assessed, as was the potential influence of land topography for the area-wide pattern observed. Most populations of T. absoluta were susceptible to abamectin, chlorfenapyr and spinosad and not to bifenthrin, triflumuron and teflubenzuron. The indoxacarb susceptibility varied in space and time. Spatial dependence was observed for abamectin and indoxacarb. The control failure likelihood of T. absoluta was higher for bifenthrin, triflumuron and teflubenzuron. A flat topography and the wind direction may favour the spread of the control failure likelihood and should be considered in designing pest management programs for T. absoluta.

  • egg exposure to pyriproxyfen in the tomato Leaf Miner tuta absoluta ovicidal activity or behavioural modulated hatching mortality
    Annals of Applied Biology, 2012
    Co-Authors: H V V Tome, Erick M G Cordeiro, Jander Fagundes Rosado, R N C Guedes
    Abstract:

    Insecticide susceptibility varies with the insect life stage and although the egg stage is sometimes perceived as the most vulnerable, it is a difficult target for insecticide application and little studied as such. Egg susceptibility to insecticides is generally considered important for insect growth regulators and insect pests of reduced mobility like Leaf Miners because of their placement on the host plant part targeted by the insecticidal application. The egg exposure to the juvenile hormone mimic pyriproxyfen was studied here in the tomato Leaf Miner Tuta absoluta (Lepidoptera: Gelechiidae), a key tomato insect pest, aiming to assess if mortality is achieved due to insecticide ovicidal activity or due to behavioural impairment of the larvae preventing egg hatching. Survival analysis of treated tomato leaves and/or eggs indicated the importance of egg exposure to pyriproxyfen leading to a significant decrease in survival with a nearly 50% reduction in survival time, which peaked at the first instar. Ovicidal activity of pyriproxyfen in the tomato Leaf Miner was negligible, but image recording and behaviour analysis indicated behavioural impairment of larval activity compromising hatching and Leaf mining by early instar larvae leading to high mortality at this stage (ca 50%). The likely causes and management implications of such findings are discussed.

  • Leaf alkaloids phenolics and coffee resistance to the Leaf Miner leucoptera coffeella lepidoptera lyonetiidae
    Journal of Economic Entomology, 2010
    Co-Authors: Sergio Tinoco Vercosa De Magalhaes, Antonio J Demuner, Flavio Lemes Fernandes, M C Picanco, R N C Guedes
    Abstract:

    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 (Guerin-Meneville & 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.

Marc Kenis - One of the best experts on this subject based on the ideXlab platform.

  • Species richness and abundance of native Leaf Miners are affected by the presence of the invasive horse-chestnut Leaf Miner
    Biological Invasions, 2010
    Co-Authors: Christelle Péré, Rumen Tomov, Sylvie Augustin, Long-hui Peng, Ted C. J. Turlings, Marc Kenis
    Abstract:

    The effect of the alien horse-chestnut Leaf Miner, Cameraria ohridella , on native fauna was studied by comparing the species richness of native Leaf Miner communities and the abundance of selected native Leaf Miner species in the presence and absence of horse-chestnut trees infested by C. ohridella , in various environments in Europe. The species richness of native Leaf Miner communities in Switzerland was lower at sites where C. ohridella was present than at control sites. In Switzerland, France and Bulgaria, several native Leaf Miner species were significantly less abundant in the vicinity of infested horse-chestnuts. The native species most affected by the presence of the invasive alien species were those occurring early in the year and sharing their parasitoid complex with C. ohridella . These results suggest apparent competition mediated by shared natural enemies because these are the only link between C. ohridella and native Leaf Miners using other food resources.

  • the invasive alien Leaf Miner cameraria ohridella and the native tree acer pseudoplatanus a fatal attraction
    Agricultural and Forest Entomology, 2010
    Co-Authors: Christelle Péré, Sylvie Augustin, Ted C. J. Turlings, Marc Kenis
    Abstract:

    1 The horse-chestnut Leaf Miner Cameraria ohridella is an invasive moth in Europe and a serious pest of horse-chestnut Aesculus hippocastanum. The moth also occasionally attacks sycamore maple Acer pseudoplatanus, when situated beside infested horse-chestnuts. 2 The main objective of the present study was to provide an overview of the relationship between C. ohridella and A. pseudoplatanus and to determine whether C. ohridella has the potential to shift to this native tree. 3 In the field, females oviposit on different deciduous tree species. Although less frequently attacked than A. hippocastanum, A. pseudoplatanus was clearly preferred for oviposition over 12 other woody species investigated. 4 Surveys in Europe demonstrated that the majority of A. pseudoplatanus trees found beside infested A. hippocastanum had mines of C. ohridella, even though more than 70% of the larvae died within the first two instars. Attack rates and development success greatly varied from site to site. Attack levels on A. pseudoplatanus were not always correlated with those on A. hippocastanum, and mines on A. pseudoplatanus were sometimes observed beside weakly-infested A. hippocastanum. 5 Field observations, experimental exposure of A. pseudoplatanus saplings and rearing trials in a common garden study showed that individual trees may vary in their susceptibility to C. ohridella, whereas there was no evidence that C. ohridella populations vary in their performance on A. pseudoplatanus. 6 To date, there is little evidence that C. ohridella represents a major risk for A. pseudoplatanus.

  • The invasive alien Leaf Miner Cameraria ohridella and the native tree Acer pseudoplatanus : a fatal attraction ?
    Agricultural and Forest Entomology, 2010
    Co-Authors: Christelle Péré, Sylvie Augustin, Ted Turlings, Marc Kenis
    Abstract:

    • The horse-chestnut Leaf Miner Cameraria ohridella is an invasive moth in Europe and a serious pest of horse-chestnut Aesculus hippocastanum. The moth also occasionally attacks sycamore maple Acer pseudoplatanus, when situated beside infested horse-chestnuts. • The main objective of the present study was to provide an overview of the relationship between C. ohridella and A. pseudoplatanus and to determine whether C. ohridella has the potential to shift to this native tree. • In the field, females oviposit on different deciduous tree species. Although less frequently attacked than A. hippocastanum, A. pseudoplatanus was clearly preferred for oviposition over 12 other woody species investigated. • Surveys in Europe demonstrated that the majority of A. pseudoplatanus trees found beside infested A. hippocastanum had mines of C. ohridella, even though more than 70% of the larvae died within the first two instars. Attack rates and development success greatly varied from site to site. Attack levels on A. pseudoplatanus were not always correlated with those on A. hippocastanum, and mines on A. pseudoplatanus were sometimes observed beside weakly-infested A. hippocastanum. • Field observations, experimental exposure of A. pseudoplatanus saplings and rearing trials in a common garden study showed that individual trees may vary in their susceptibility to C. ohridella, whereas there was no evidence that C. ohridella populations vary in their performance on A. pseudoplatanus. • To date, there is little evidence that C. ohridella represents a major risk for A. pseudoplatanus.

  • prospects for the biological control of the groundnut Leaf Miner aproaerema modicella in africa
    Cab Reviews: Perspectives in Agriculture Veterinary Science Nutrition and Natural Resources, 2006
    Co-Authors: Marc Kenis, Domingos Cugala
    Abstract:

    The groundnut Leaf Miner, Aproaerema modicella, is a pest of groundnut and soybean in South and Southeast Asia that has recently invaded Africa. It was first found in Uganda in 1998 and is now recorded in Mozambique, Malawi, Democratic Republic of Congo and South Africa. In all African countries where A. modicella has been found, the pest has reached outbreak densities and severe yield losses have been observed on groundnut. In this paper, we review the natural enemies of A. modicella in Asia and evaluate their potential for biological control in Africa. The main natural enemies of A. modicella in Asia are parasitoids. Over 30 primary parasitoid species have been recorded with mean parasitism rates fluctuating between 20 and 50% and peak parasitism reaching 53–91%. The most often cited parasitoids belong to the genera Goniozus (Hym.: Bethylidae), Apanteles, Bracon, Chelonus and Avga (Hym.: Braconidae), Brachymeria (Hym.: Chalcididae), and Stenomesius, Sympiesis and Tetrastichus (Hym.: Eulophidae). Predators and pathogens have been poorly studied. A. modicella is a promising target for classical biological control using natural enemies from Asia. Damage levels are, on average, higher in Africa than in Asia, where parasitoids, and possibly predators and pathogens, probably play an important role in the natural control of the pest. However, surveys are needed in Asia to better study natural enemies of A. modicella before selecting the most suitable agents. Until now, most studies on natural enemies were carried out in India, where A. modicella is considered a serious pest. New surveys should focus on other regions, where the moth causes little damage and very little is known on its natural enemy complex.

  • the horse chestnut Leaf Miner in europe prospects and constraints for biological control
    Second International Symposium on Biological Control of Arthropods Davos Switzerland 12-16 September 2005., 2005
    Co-Authors: Marc Kenis, Rumen Tomov, Ales Svatos, P Schlinsog, C L Vaamonde, W Heitland, G Grabenweger, S Girardoz, J Freise, N Avtzis
    Abstract:

    The horse-chestnut Leaf Miner, Cameraria ohridella Deschka and Dimic (Lepidoptera: Gracillariidae), is a moth of unknown origin that was first observed in Macedonia in the late 1970s. Since then, it has spread over most of Europe, causing permanent outbreaks on the European horse-chestnut, Aesculus hippocastanum L. (Sapindales: Sapindaceae), a major urban tree in Europe. The horse-chestnut is endemic to the Balkans where the few remaining

Marcelo Coutinho Picanco - One of the best experts on this subject based on the ideXlab platform.

  • insecticide toxicity and walking response of three pirate bug predators of the tomato Leaf Miner tuta absoluta
    Agricultural and Forest Entomology, 2014
    Co-Authors: Renata Ramos Pereira, Marcelo Coutinho Picanco, Paulo A Santana, Suzana S Moreira, R N C Guedes, Alberto S Correa
    Abstract:

    The tomato Leaf Miner Tuta absoluta is a key pest of the tomato and is of global significance. Insecticide is the primary method for controlling this pest, requiring a search for compounds with a low toxicity to nontarget organisms. We assessed the toxicity of eight insecticides to T. absoluta and its pirate bug predators Orius tristicolor, Amphiareus constrictus and Blaptostethus pallescens (Hemiptera: Heteroptera: Anthocoridae). We also assessed the effect of insecticide synergists on their toxicity to the predators, as well as their walking response to insecticide exposure. All insecticides, with the exception of methamidophos, exhibited the minimum efficacy threshold required by the Brazilian legislation (80% efficacy) at concentrations lower than the registered label rates. Indoxacarb and chlorantraniliprole exhibited a lower toxicity to the pirate bug predators than to the tomato Leaf Miner. The results obtained with the synergized insecticides suggest the involvement of cytochrome P450-dependent monooxygenases as the primary detoxification enzymes minimizing insecticide toxicity in the pirate bug predators. The insecticides led to a reduction in predator walking activity, especially abamectin and indoxacarb, which significantly minimized predator exposure. The results of the present study indicate that novel insecticides, especially chlorantraniliprole, are better suited to sustainable integrated management programmes of the tomato Leaf Miner.

  • spatial and temporal variation in the control failure likelihood of the tomato Leaf Miner tuta absoluta
    Annals of Applied Biology, 2013
    Co-Authors: Pablo Costa Gontijo, Marcelo Coutinho Picanco, E J G Pereira, Julio Claudio Martins, Mateus Chediak, R N C Guedes
    Abstract:

    Insecticide resistance is frequently associated with field control failure, but such an assessment of its likelihood seldom occurs. This phenomenon is a potential cause of the control failure of the tomato Leaf Miner Tuta absoluta (Lepidoptera: Gelechiidae); therefore we surveyed insecticide resistance as the control failure likelihood for a duration of 7 years in 20 field populations of this species. The insecticide label rate was used as the discriminating concentration, and the minimum efficacy threshold required for insecticides in Brazil (i.e. 80% efficacy) was the targeted efficacy. The spatial and temporal variations of the control failure likelihood were also assessed, as was the potential influence of land topography for the area-wide pattern observed. Most populations of T. absoluta were susceptible to abamectin, chlorfenapyr and spinosad and not to bifenthrin, triflumuron and teflubenzuron. The indoxacarb susceptibility varied in space and time. Spatial dependence was observed for abamectin and indoxacarb. The control failure likelihood of T. absoluta was higher for bifenthrin, triflumuron and teflubenzuron. A flat topography and the wind direction may favour the spread of the control failure likelihood and should be considered in designing pest management programs for T. absoluta.

  • genetic diversity among tomato accessions infested by different tomato Leaf Miner populations
    Horticultura Brasileira, 2005
    Co-Authors: Gisele Rodrigues Moreira, Marcelo Coutinho Picanco, Derly Jose Henriques Da Silva, Luiz Alexandre Peternelli, Fabiano Ricardo Brunele Caliman
    Abstract:

    The genetic diversity among Lycopersicon spp. accesses was studied, concerning the resistance to various Tuta absoluta populations. An experiment was carried out using four populations of the insect originally from Uberlândia, Vicosa, Camocim de Sao Felix and Santa Teresa and five tomato accessions, 'Santa Clara', 'Moneymaker', TOM-601, 'PI 126445' (L. hirsutum f. typicum) and 'PI 134417' (L. hirsutum f. glabratum). Tukey mean comparing test and Tocher grouping were accomplished and the relative importance of T. absoluta characters to the genetic divergence among tomato accessions was evaluated by Singh method. There was genetic variability among tomato accessions when infested by tomato Leaf Miner populations collected from different regions of Brazil. The 'Santa Clara' accession was most susceptible to Santa Teresa population. 'Moneymaker' and 'TOM-601' were most resistant to Camocim de Sao Felix and Santa Teresa populations, respectively. 'PI 126445' was most resistant to Santa Teresa and Vicosa populations. 'PI 134417' was most resistance to Vicosa population. 'Moneymaker' and 'TOM-601' can be utilized in breeding programs aiming to obtain tomato plants resistant to the tomato Leaf Miner. The characteristics that most contributed to the genetic divergence among tomato accessions were larval mortality, female pupae number and male pupae number. The characters larval period and male pupae weight cannot be eliminated in future resistance evaluations to the population tomato Leaf Miner from Uberlândia.

  • Insecticide use and organophosphate resistance in the coffee Leaf Miner Leucoptera coffeella (Lepidoptera: Lyonetiidae).
    Bulletin of entomological research, 2002
    Co-Authors: Daniel B. Fragoso, Marcelo Coutinho Picanco, Raul Narciso C. Guedes, L. Zambolim
    Abstract:

    Increasing rates of insecticide use against the coffee Leaf Miner Leucoptera coffeella (Guerin-Meneville) 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 LC 99 s 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.

Tomas Roslin - One of the best experts on this subject based on the ideXlab platform.

  • competition as a structuring force in Leaf Miner communities
    Oikos, 2009
    Co-Authors: Ayco J M Tack, Otso Ovaskainen, Philip J Harrison, Tomas Roslin
    Abstract:

    The role of competition in structuring communities of herbivorous insects is still debated. Despite this, few studies have simultaneously investigated the strength of various forms of competition and their effect on community composition. In this study, we examine the extent to which different types of competition will affect the presence and abundance of individual Leaf Miner species in local communities on oak trees Quercus robur. We first use a laboratory experiment to quantify the strength of intra- and interspecific competition. We then conduct a large-scale field experiment to determine whether competition occurring in one year extends to the next. Finally, we use observational field data to examine the extent to which mechanisms of competition uncovered in the two experiments actually reflect into patterns of co-occurrence in nature. In our experiment, we found direct competition at the Leaf-level to be stronger among conspecific than among heterospecific individuals. Indirect competition among conspecifics lowered the survival and weight of larvae of T. ekebladella, both at the branch and the tree-level. In contrast, indirect competition among heterospecifics was only detected in one out of three species pairs examined. In the field experiment, the presence of a given moth species in one year affected the relative abundance of Leaf Miner species in the next year. Nevertheless, patterns of competition observed in these experiments did not translate into repulsion among free-ranging Leaf Miners: conspecific larvae of four Leaf-mining species were aggregated on the same trees, shoots and leaves. In contrast, heterospecific larvae were only aggregated at the tree-level. We propose that despite the fact that Leaf Miners do compete and that such effects extend through time, the incidence and strength of competition is relatively small at realistic densities. Hence, competition will likely be of minor importance in shaping the distribution of Leaf Miners in a natural setting.

  • a tree in the eyes of a moth temporal variation in oak Leaf quality and Leaf Miner performance
    Oikos, 2007
    Co-Authors: Sofia Gripenberg, Juhapekka Salminen, Tomas Roslin
    Abstract:

    When examined at any moment in time, different parts of an individual oak tree exhibit almost as large differences in quality as different trees. But how consistent are such patterns in time? In this paper, we use intraclass correlations to assess the temporal consistency of host plant quality at several spatial scales. As measures of quality, we use both individual chemical attributes (phenolic contents) and the overall performance (larval survival) of the host-specific Leaf-Miner Tischeria ekebladella . Concentrations of 24 phenolic compounds were monitored on seven trees throughout a season. Variation in mine initiation and larval survival rates was assessed for individuals transplanted to another set of trees early versus later in the season, while year-to-year variation in larval survival was studied through stratified surveys of wild individuals during three years. At all time scales considered, measures of host quality were moderately consistent: a tree favourable in quality at one point in time often remained so, but there was abundant variation around this relationship (r /0.40.6). One hierarchical level deviated from this general pattern: on individual branches, larval survival rates varied randomly among years (r /0). Our study suggests that the quality of trees, and in particular of smaller units within trees, may be difficult to predict both in space and in time. To account for this, insects might benefit from adopting a bethedging strategy when selecting resources.

Anne Frary - One of the best experts on this subject based on the ideXlab platform.

  • cry1ac mediated resistance to tomato Leaf Miner tuta absoluta in tomato
    Plant Cell Tissue and Organ Culture, 2017
    Co-Authors: Hatice Selale, Fatih Dagli, Nedim Mutlu, Sami Doganlar, Anne Frary
    Abstract:

    Tomato Leaf Miner (Tuta absoluta) is a major pest of tomato in regions with hot climates such as South America and the Mediterranean. This insect feeds on almost every part of the plant and forms galleries while feeding on the plant’s inner tissues. Thus, it can cause plant death and is costly and difficult to control with chemical sprays. In this study, we transferred a modified Bacillus thuringiensis cry1Ac gene to tomato plants via Agrobacterium tumefaciens mediated transformation. Introduction of the cry1Ac gene to the tomato genome was confirmed with PCR and Southern blot analysis in 12 independent events. Insertion sites of the transgene in the tomato genome were determined with TAIL-PCR (thermal asymmetric interlaced polymerase chain reaction) for four selected transgenic lines. Cry1Ac gene expression was verified at both the transcriptional and translational levels, with RT-qPCR and Western blot analyses, respectively. Expression of the Cry1Ac protein in tomato resulted in T. absoluta mortality rates of 38–100% depending on transgenic line. In addition, gallery formation was reduced in 57–100% of the transgenic plants. Moreover, it was found that a single copy of the gene in the hemizygous condition is sufficient to confer tolerance to Leaf Miner. This is the first reported development of tomato plants resistant to T. absoluta. These transgenic plants are promising for development of commercial tomato cultivars resistant to Leaf Miner, which will limit the use of environmentally harmful chemicals for control of this pest.