Evaluation of two methods for the protection of tomato crops against the tomato leafminer Tuta absoluta (Meyrick) under greenhouses in Tunisia

The evaluation of two methods of plant protection in tomato crops cultivated in greenhouses against Tuta absoluta (Meyrick) in the region of Teboulba in Tunisia was performed. This study evaluated the use of insect‐proof screens alone or in combination with one sex pheromone water trap compared to a control greenhouse not equipped with either. The study confirms that the use of one sex pheromone water trap combined with insect‐proof covering of doors and aeration openings is sufficient to guarantee good crop protection. This combined control system allowed a low density of the pest (less than 2 individuals per leaf) to be maintained and a mean number of mines below 1 mine per leaf.     

The tomato leafminer Tuta absoluta (Meyrick) in Tunisia: current status and management strategies

The tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) was first identified in the region of Akkouda in October 2008 before it spread to all tomato‐producing areas in Tunisia. The introduction of this pest disturbed existing pest control programmes in greenhouses and open fields, forcing Tunisian growers to use more chemicals to reduce its impact on their crops. A national programme was adopted to control T. absoluta, including cultural practices, the use of pheromones, the installation of insect‐proof screens in greenhouses, and the use of organic insecticides including Bacillus thuringiensis Kurstaki (Bt) and plant extract‐based products. In addition, a few experiments in biological control, using the predatory Mirid Nesidiocoris tenuis Reuter (Heteroptera: Miridae) and the parasitoid wasp Trichogramma cacoeciae Marchal (Hymenoptera: Trichogrammatidae), were conducted in greenhouses and open‐field crops (producing tomatoes for fresh consumption as well as for processing). This paper describes the status of T. absoluta in Tunisia, including data collected from sex pheromone traps installed in six tomato‐producing areas (Takelssa, Korba, Teboulba, Bekalta, Sousse and Kairouan) between 2009 and 2011, and control strategies in greenhouses and open fields.     

Experimental studies on Tuta absoluta (Meyrick) in protected tomato crops in France: biological control and integrated crop protection

Tuta absoluta is a pest from South America which has been detected in many European and Mediterranean countries since 2006. It was identified in Corsica and the South of France in late 2008, and by 2010 this Lepidopteran species had spread to further tomato‐production areas. The pest is present mainly on tomatoes in protected and field crops, and damage on leaves and fruit can be so severe that it can lead to total destruction of the plant. Since 2010, studies have been carried out in experimental insect‐proof glasshouses with artificial infestations of the pest. The objective was to gain better knowledge of this emergent pest and to develop adapted control strategies under the conditions of the South‐East of France. Integrated pest management is widely used on tomato crops in France, and the predator Macrolophus pygmaeus and the parasitoid Trichogramma achaeae were studied, alone and in combination. The possible effect of the concurrent prey Trialeurodes vaporariorum on the impact of the predator on T. absoluta was also studied. The best results were obtained when the two beneficials were released in combination, even in the presence of whiteflies T. vaporariorum.     

Comparison of pheromone lures used in mass trapping to control the tomato leafminer Tuta absoluta (Meyrick, 1917) in industrial tomato crops in Kairouan (Tunisia)

An experimental trial of integrated pest management against Tuta absoluta (Meyrick) based on mass trapping with a density of 32 traps per hectare was conducted in a 5 ha open‐field tomato crop. During this trial, the efficiency of three brands of sex pheromone dispenser commercialized in Tunisia was tested. The ‘superdosed’ pheromone lure type TUA‐Optima^® (Russell IPM, Deeside, Flintshire, CH5 2LA, United Kingdom) loaded with 0.8 mg of synthetic pheromone was more attractive to males of T. absoluta, and these lures should be used with high populations. Standard lures Pherodis^® and TUA‐500^® containing 0.5 mg of pheromone were less attractive, and can be used in open‐field tomato crops with lower populations of T. absoluta. An assessment of the susceptibility of crop borders to T. absoluta, based on data collected from traps, revealed that levels of adult T. absoluta were similar between borders with either tomato or cereal crops. Particular attention should thus be paid to crop borders even when not adjacent to other tomato crops.     

Host plants record for tomato leaf miner Tuta absoluta (Meyrick) in Sudan

This paper presents the results from a survey that was carried out to determine the host plants of tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in five States in Sudan. This survey was carried out in greenhouses and open‐field vegetable production areas between the years 2011 and 2014 using pheromone traps. The survey showed that the main host plant of T. absoluta is tomato (Lycopersicon esculentum), but it also attacks potato (Solanum tuberosum), eggplant (S. melongena) Jimson weed (Datura stramonium) and S. dubium in the family Solanaceae, and broad bean (Vicia faba) and alfalfa plant (Medicago sativa) in the family Fabaceae. This paper is the first record of the following plans being hosts for T. absoluta: Watermelon (Citrullus lanatus) in the family Cucurbitaceae, Physic nut (Jatropha curcas) in the family Euphorbiaceae, spiny amaranth (Amaranthus spinosus) in the family Amaranthaceae, Ramtouk (Xanthium brasilicum) in the family Asteraceae and S. dubium. The study showed that the leafminer male numbers and the symptoms were significantly increased in S. melongena and S. dubium after severe damage and complete loss of the main host, the tomato crop and these two species may be the preferred alternative host plants.     

First record of tomato leafminer Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) in Kyrgyzstan

This short note reports the first record of the tomato leaf miner Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) in Kyrgyzstan. This pest was found in February 2017 in greenhouses producing tomatoes, located 15 km from Bishkek. Identification of the pest was carried out in the Plant Protection Department, Çukurova University, Turkey based on the morphology of adults and larvae and the male genitalia. According to initial surveys this pest could be a major threat to tomato production in Kyrgyzstan.     

Fortuitous parasitoids of the invasive tomato leafminer Tuta absoluta in Tunisia

The South American tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a major threat to tomato (Solanum lycopersicum L.) crops. After its first detection in Spain in 2006, it spread rapidly through the Western Palaearctic region, arriving in Tunisia 2 years later. The aim of this research was to assess whether generalist indigenous parasitoids are adapting to this exotic host in Tunisian tomato crops. For this, we conducted a survey in four Tunisian tomato-growing areas by sampling infested leaves of tomato and solanaceous weeds and exposing artificially infested sentinel plants. Two ectoparasitoid species were found attacking and developing on T. absoluta: Bracon sp. (Hymenoptera: Braconidae) and Necremnus sp. nr artynes (Hymenoptera: Eulophidae), whereas no egg or pupal parasitoids were found. The eulophid wasp was the most abundant with a peak of apparent parasitism rate of 25.5%. It emerged from parasitized T. absoluta young larvae in exposed sentinel plants and in sampled infested tomato leaves, both in greenhouse and open field cultivations. Bracon sp. showed a gregarious development on T. absoluta mature larvae and it was collected only on sentinel plants exposed in the Ragueda (Kiarouan) site, with 10.23% of estimated parasitism. Although further research is still needed to assess properly the ecological role of these parasitoids in the biological control of T. absoluta, this study represents the first step toward establishing the scientific basis for including these parasitoids in the Tunisian IPM and biological programs against this pest.     

First record of the tomato leafminer,Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in Sudan

An outbreak of larvae and adults of a devastating moth was noted to be causing severe damage in tomato grown in greenhouses at Khartoum State, Sudan during June 2010. Symptoms included foliage mining and leaves drying. Photographs of symptoms and larvae and adults of the pest (and subsequently specimens) were sent to Russell IPM, UK and the Finnish Museum of Natural History for identification. The pest was identified as Tuta absoluta (Meyrick), (Lepidoptera: Gelechiidae). This is the first official record of T. absoluta in Sudan, based on surveys in tomato production areas in Khartoum, Gezira, Red Sea and North Kordofan States and eggplant and potato in Khartoum State. Severe yield loss due to the serious feeding damage on foliage and fruits infestation was reported on tomato and eggplant fields at Khartoum State.     

Use of predatory mirids for control of the tomato borer Tuta absoluta (Meyrick) in Sardinian greenhouse tomatoes

The introduction of Tuta absoluta in Sardinia (Italy) has caused an important increase in the number of insecticide treatments applied for pest management on greenhouse tomatoes, thus raising growers' demand for alternative control options. To evaluate the efficacy of releasing two specimens of Macrolophus pygmaeus or Nesidiocoris tenuis per m² for the control of tomato borer infestations, an investigation was conducted under field conditions between August 2010 and July 2011. The tests were carried out on 18 commercial greenhouse crops. Fifteen other greenhouses, where no biocontrol agents were released, were also surveyed as controls. The release of the mirid bugs resulted in poor population growth of predators, which reached a peak density of 1.79 individuals per plant. In approximately half of the cases, this was caused by the application of pesticides (usually abamectin and oxamyl) which are highly toxic to the predatory mirids. However, even in crops where only products regarded as harmless to beneficials were used (e.g. Bacillus thuringiensis‐based insecticides), both M. pygmaeus and N. tenuis failed to achieve the levels necessary for effective pest control. Presumably factors other than pesticide‐related mortality contributed significantly to delaying mirid population build‐up. Further studies are necessary to evaluate the feasibility of improving the efficacy of releases of the predatory mirids by the implementation of measures that may contribute to enhancing the establishment of these beneficials on tomato crops.     

First record of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in Burundi

This study to detect Tuta absoluta was carried out at four sites in western Burundi from March to July 2018. Delta traps containing Tutrack pheromone and sticky paper were installed in tomato fields at 40 cm from the ground. Sample collection was carried out twice a week. The results confirmed the presence of T. absoluta in Burundi. Effective pest control is required to avoid heavy losses on tomato production.     

设施番茄4种栽培方式下番茄潜叶蛾对化蛹场所的选择性研究

为提高番茄潜叶蛾的监测与防控效率,在樱桃番茄生产温棚开展了双色地膜土栽、地砖托盘盆栽、地砖盆栽、地布盆栽4种栽培方式下番茄潜叶蛾对化蛹场所的选择性研究。依据栽培方式,调查了12种可能的化蛹场所。结果表明,番茄的栽培方式不同,番茄潜叶蛾的化蛹场所亦有明显变化。双色地膜土栽方式下,6种场所的总计平均化蛹数量和化蛹数量占比中,地膜覆盖土显著高于其他场所,依次为地膜覆盖土>种植孔周边和茎秆>叶片;叶柄和果实上未观察到有幼虫化蛹。地砖托盘盆栽方式下,9种场所的总计平均化蛹数量中,花盆托盘底部和花盆翻边显著多于花盆盆底,其他场所未观察到有幼虫化蛹;化蛹数量占比中,花盆托盘底部显著高于其他场所,依次为花盆托盘底部>花盆翻边>花盆盆底。地砖盆栽方式下,8种场所的总计平均化蛹数量中,地砖缝隙和花盆翻边显著多于花盆盆底,其他场所未观察到有幼虫化蛹;化蛹数量占比中,地砖缝隙显著高于花盆翻边和花盆盆底。地布盆栽方式下,8种场所的总计平均化蛹数量和化蛹数量占比中,花盆盆底显著高于其他场所,依次为花盆盆底>花盆翻边>地布表面,其他场所未观察到幼虫化蛹。双色地膜土栽方式下4种化蛹...     

Life-table analyses for the tomato leaf miner,Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae): effects of plant genotype

BACKGROUND

Host plant resistance plays an important role in integrated pest management programs. Crop resistance assessments commonly focus on only a single dependent variable, such as larval survival/plant damage, which limits the ability to appreciate the impact of host plants on pest populations in the full sense. Therefore, we performed life-table analyses for tomato leaf miner Tuta absoluta, on 19 Solanum lycopersicum genotypes and a wild Solanum habrochaites accession. These analyses assess the ability of the pest to attain a high population density on different tomato genotypes. Based on the resulting ranking of tomato resistance at the vegetative stage (45-day-old plants), we tested the resistance of six selected genotypes at the reproductive stage (4-month-old plants).

RESULTS

T. absoluta performance was significantly inferior on vegetative-stage S. habrochaites plants (LA 1777); time taken for the first instars to mine the leaves (5 ± 0.14 days), development time of early- and late-stage larvae (8.8 ± 0.2 and 4.2 ± 0.2 days, respectively), pupal period (11.2 ± 0.58 days), and total developmental time (29.4 ± 0.83 days) were significantly longer, fecundity was significantly lower (18.66 ± 7.24 days), and the highest total mortality (63.33%) also recorded compared with other genotypes, resulting in the lowest net reproductive rate (R₀) (11.20 ± 2.51). For the six selected genotypes, the ranking of plant resistance did not change between plants at the vegetative and reproductive stages.

CONCLUSION

This study suggested that of 20 screened tomato genotypes, LA 1777 and EC-620343 are the least suitable hosts for T. absoluta to establish fast-growing populations, and thus can be employed in integrated T. absoluta management. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Abamectin resistance and synergism in Brazilian populations of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

Failures in the control of the tomato leafminer Tuta absoluta (Meyrick) by means of abamectin in Brazil, and a recent report of abamectin resistance in Brazilian populations of this pest species, led to the investigation of the possible involvement of detoxification enzymes using insecticide synergists. Resistance to abamectin was observed in all populations when compared with the standard susceptible population, with resistance ratios ranging from 5.2- to 9.4-fold. Piperonyl butoxide was the most efficient synergist with abamectin synergism ratios ranging from 3.0- to 5.3-fold and providing significant resistance suppression, but complete suppression of abamectin resistance was only obtained in one population of T. absoluta . Triphenylphosphate was an abamectin synergist which was not as efficient as piperonyl butoxide, but it provided complete suppression of abamectin resistance in four of the six resistant populations studied, suggesting a major involvement of esterases as an abamectin resistance mechanism in these populations. The importance of cytochrome P450, inhibited by piperonyl butoxide, seems secondary to esterases. Diethyl maleate also synergized abamectin in nearly all populations, but provided only partial suppression of abamectin resistance in the leafminer populations studied. Therefore, glutathione-S-transferases seem to be of minor importance as an abamectin resistance mechanism in Brazilian populations of T. absoluta .     

Susceptibility of tomato borer,Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) populations from Turkey to 7 different insecticides in laboratory bioassay

The tomato borer, Tuta absoluta (Meyrick), was first recorded in Turkey in August 2009 and rapidly became a serious pest in the Mediterranean and Aegean coastal regions in field and greenhouse grown tomatoes. Currently, insecticides are considered one of the major tools for the management of T. absoluta in Turkey. This study, investigated the efficacy of 7 different insecticides, against T. absoluta in laboratory bioassays. To determine the lethal concentration (LC) values and feeding activity of the larvae, tomato leaf parts mined by 1–3 day old L1 larvae were dipped into different insecticide concentrations. Mortality was recorded 5 days after insecticide treatments. Spinosad, chlorantraniliprole + abamectin or indoxacarb treatment resulted in 100% mortality with minimal or no feeding in all populations at their recommended doses of 120, 50.4 and 60 mg a.s. L^?1, respectively. In general, the LC₉₉ values of populations for these insecticides were similar and also lower than that of the recommended field doses. The effect of pyridalyl was low, resulting in low mortality with serious feeding damage at the dose of 125 mg a.s. L^?1. The efficacies of abamectin, metaflumizone and azadirachtin were found to be moderate to low at the recommended doses (4.5, 240 and 50 mg a.s. L^?1, respectively). However, these insecticides may affect pupation and adult emergence rates hence further studies are recommended to investigate these insecticides.     

Tuta absoluta (Meyrick) (Lepidoptera,Gelechiidae) in the Republic of Srpska (Bosnia and Herzegovina)

Pheromone traps were placed in the market place in Banja Luka, and in greenhouses and open field tomato crops, on 13 September 2010 to determine the presence of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in Banja Luka region. Based on examination of traps, the presence of T. absoluta was confirmed for the first time in the Republic of Srpska. Only mines of Liriomyza species were found by examining leaves under a stereomicroscope. In 2011, pheromone traps were placed in greenhouses at several locations (Banja Luka, Prijedor, Novi Grad, Kozarska Dubica, Ljubinje and Trebinje) at the beginning of June, and in open fields in Bijeljina and Trebinje at the beginning of September. Examination of the traps was carried out at intervals of 15 days. A sample of 100 leaves, taken from 20 randomly selected plants, was examined in order to evaluate the intensity of the attack. The first adults were caught in greenhouses in Ljubinje and Trebinje on 18 June 2011; in open field crops in Bijeljina on 9 September 2011 and in Banja Luka on 5 October 2011. Adults were not captured in Prijedor, Novi Grad or Kozarska Dubica, and no mined leaves were observed. The intensity of attack was evaluated on the basis of active infestation (percentage of leaves with active mines compared with all mined leaves). The strongest intensity of active infestation was recorded in the open field crops in Trebinje, where 19% of leaves with active mines were found.     

Management of the tomato borer,Tuta absoluta in Tunisia with novel insecticides and plant extracts

Tomato, Lycopersicon esculentum Mill is a vegetable crop of major importance in Tunisia. Since its detection in 2008, the tomato borer, Tuta absoluta (Meyrick), (Lepidoptera: Gelechiidae) became a serious insect pest attacking both outdoor and greenhouse tomatoes. Its control relies primarily on insecticides; hence the diversification of active substances including natural products is urgently required. The effectiveness of novel insecticides and plant extracts for the control of T. absoluta were investigated in Tunisia on tomatoes grown in greenhouses and in the laboratory in 2011. In tomato greenhouses, the following products were evaluated: Ampligo 150ZS (chlorantraniliprole + lambda‐cyhalothrin), VoliamTargo 063 SC (chlorantraniliprole + abamectin), Tracer240 SC (spinosad), Nimbecidine (azadirachtin 0.03%), Tutafort (plant extracts), Vydate (oxamyl) and Biocatch (Verticillium lecanii). In the laboratory, the products evaluated were: Ampligo 150ZS (chlorantraniliprole + lambda‐cyhalothrin), Movento OD (spirotetramat), Evisect SP (thiocyclam), Challenger SC (chlorfenapyr), Cyproma WP (cyromazine), Vydate (oxamyl), Armorex (plant extracts), Konflic (plant extracts) and Deffort (plant extracts). Greenhouse trials show good efficacy of the following products: Tracer, Nimbecidine, Biocatch, VoliamTargo, Tutafort and Vydate. However, laboratory trials demonstrate good performance of Challenger, Ampligo, Movento, Armorex, Deffort and Konflic. The integration of these products in an integrated pest management approach is discussed.     

Bioactivity of compounds from Acmella oleracea against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) and selectivity to two non-target species

BACKGROUND: Tropical plants are recognised sources of bioactive compounds that can be used for pest control. The objective of this study was to evaluate the biological activity of compounds present in Acmella oleracea (Asteracea) against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), which is the main pest of tomato crops in Latin America. The selectivity of these compounds to the predator Solenopsis saevissima (Smith) (Hymenoptera: Formicidae) and to the pollinator Tetragonisca angustula (Latr.) (Hymenoptera: Apidae: Meliponinae) was also of interest. RESULTS: A bioassay screening with hexane and ethanol extracts from 23 plants was performed. The hexane extract of A. oleraceae was the most active of the extracts and was selected for further study. The following three alkamides were isolated from a hexane extract of the aerial parts of A. oleracea : spilanthol, (E)‐N‐isobutylundeca‐2‐en‐8,10‐diynamide and (R, E)‐N‐(2‐methylbutyl)undeca‐2‐en‐8,10‐diynamide. All of the isolated compounds showed insecticidal activity, with spilanthol being the most active (LD₅₀ = 0.13 µg mg^?1) against T. absoluta . The alkamides were selective to both beneficial species studied. CONCLUSION: The crude hexane extract of A. oleraceae showed high insecticidal activity and can be used to control T. absoluta in organic or conventional crops. Quantification of LD₅₀ values of isolated compounds against T. absoluta showed that alkamides could serve as potent insecticides for T. absoluta control programmes. Spilanthol was the main alkamide active isolated. This alkamide is the most promising as it has the highest insecticidal activity and is selective to non‐target organisms. Copyright © 2011 Society of Chemical Industry