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Tomato spotted wilt virus (TSWV) is economically prominent disease for its impact on tobacco (Nicotiana tabacum L.) production worldwide. An increase of the incidence of symptoms typical of TSWV has been observed in tobacco production areas in Denizli province of Turkey where tobacco is significantly grown. Surveys were conducted to determine the prevalence status of TSWV in tobacco cultivars and its possible sources of infections in four tobacco growing districts of Denizli province. A total of 501 plant samples from field-grown tobaccos, weeds, potential intermediate hosts, seedlings and seeds were collected during 2019 and tested by DAS-ELISA. Of these plants, 243 belong to 55 different weed species from 26 different families with intermediate host potential. Throughout the study, 40 crop plant samples which could be intermediate hosts and 39 tobacco seed samples were also taken for testing. Adult thrips specimens were picked up from the fields and brought to the laboratory for preparations. Four vector virus species were detected when adult thrips individuals were diagnosed: Thrips tabaci Lindeman (Thysanoptera: Thripidae), Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), Aeolothrips intermedius Bagnall (Thysanoptera: Aeolothripidae) and Thrips major Uzel (Thysanoptera: Thripidae). Of the 179 tobaccos sampled, 31.2% was positive; besides, of 243 weeds tested 10 were found to be infected. Echinochloa crus-,alli and Tordylium apulum were determined to be new host recordings for TSWV infection. Only one tomato plant from the crop plants as intermediate also confirmed in tobacco fields., Aegean Exporters'Associations, This work was supported by Aegean Exporters'Associations.

Generalist predators potentially have access to a wide array of prey, but it is little studied how experience with specific prey affects preference for this prey. In particular, it is unknown how experience with pest prey affects predator foraging decisions in cases where the pest is nutritious but protected by a repelling, potentially deadly defence. We investigated preference of the soil predatory mite Gaeolaelaps aculeifer Canestrini for the risky pest springtail Protaphorura fimata Gisin relative to the safe non-pest springtail Folsomia candida Willem. Egg production under foraging on live or dead individuals of either prey showed that the two species had equal nutritional quality for G. aculeifer, but indicated that live F. candida were more difficult to catch than live P. fimata. Importantly, some G. aculeifer were killed by P. fimata defence secretions, demonstrating that live P. fimata are risky prey. Preference for P. fimata was generally high when mites were given a choice between a live individual of either prey, but this preference was reduced following exposure to live individuals of P. fimata. Furthermore, fewer G. aculeifer killed a prey and time until kill was longer after experience with live P. fimata. These findings indicate that live P. fimata induced a partial aversion on G. aculeifer during exposure. Our study shows that generalist predators can reduce their preference for risky prey following exposure. This indicates that generalist predators used in biological control against risky prey are most efficient against this prey if not exposed to it prior to release.

Biological pest control in greenhouse crops is usually based on periodical releases of mass-produced natural enemies, and this method has been successfully applied for decades. However, in some cases there are shortcomings in pest control efficacy, which often can be attributed to the poor establishment of natural enemies. Their establishment and population numbers can be enhanced by providing additional resources, such as alternative food, prey, hosts, oviposition sites or shelters. Furthermore, natural enemy efficacy can be enhanced by using volatiles, adapting the greenhouse climate, avoiding pesticide side-effects and minimizing disrupting food web complexities. The special case of high value crops in a protected greenhouse environment offers tremendous opportunities to design and manage the system in ways that increase crop resilience to pest infestations. While we have outlined opportunities and tools to develop such systems, this review also identifies knowledge gaps, where additional research is needed to optimize these tools.

Untargeted LCMS profiling of semi-polar metabolites followed by metabolite quantitative trait locus (mQTL) analysis was performed in ripe pepper fruits of 113 F2 plants derived from a cross between Capsicum annuum AC1979 (no. 19) and Capsicum chinense No. 4661 Selection (no. 18). The parental accessions were selected based on their variation in fruit morphological characteristics and fruit content of some target phytonutrients. Clear segregation of fruit colour and fruit metabolite profiles was observed in the F2 population. The F2 plants formed three clusters based on their metabolite profiles. Of the total of 542 metabolites, 52 could be annotated, including a range of flavonoids, such as flavone C-glycosides, flavonol O-glycosides and naringenin chalcone, as well as several phenylpropanoids, a capsaicin analogue, fatty acid derivatives and amino acid derivatives. Interval mapping revealed 279 mQTLs in total. Two mQTL hotspots were found on chromosome 9. These two chromosomal regions regulated the relative levels of 35 and 103 metabolites, respectively. Analysis also revealed an mQTL for a capsaicin analogue, located on chromosome 7. Confirmation of flavonoid mQTLs using a set of six flavonoid candidate gene markers and their corresponding expression data (expression QTLs) indicated the Ca-MYB12 transcription factor gene on chromosome 1 and the gene encoding flavone synthase (FS-2) on chromosome 6 as likely causative genes determining the variation in naringenin chalcone and flavone C-glycosides, respectively, in this population. The combination of large-scale metabolite profiling and QTL analysis provided valuable insight into the genomic regions and genes important for the production of (secondary) metabolites in pepper fruit. This will impact breeding strategies aimed at optimising the content of specific metabolites in pepper fruit. Electronic supplementary material The online version of this article (doi:10.1007/s11032-013-9967-0) contains supplementary material, which is available to authorized users.

Solanum galapagense is closely related to the cultivated tomato and can show a very good resistance towards whitefly. A segregating population resulting from a cross between the cultivated tomato and a whitefly resistant S. galapagense was created and used for mapping whitefly resistance and related traits, which made it possible to study the genetic basis of the resistance. Quantitative trait loci (QTL) for adult survival co-localized with type IV trichome characteristics (presence, density, gland longevity and gland size). A major QTL (Wf-1) was found for adult survival and trichome characters on Chromosome 2. This QTL explained 54.1 % of the variation in adult survival and 81.5 % of the occurrence of type IV trichomes. A minor QTL (Wf-2) for adult survival and trichome characters was identified on Chromosome 9. The major QTL was confirmed in F3 populations. Comprehensive metabolomics, based on GCMS profiling, revealed that 16 metabolites segregating in the F2 mapping population were associated with Wf-1 and/or Wf-2. Analysis of the 10 most resistant and susceptible F2 genotypes by LCMS showed that several acyl sugars were present in significantly higher concentration in the whitefly resistant genotypes, suggesting a role for these components in the resistance as well. Our results show that whitefly resistance in S. galapagense seems to inherit relatively simple compared to whitefly resistance from other sources and this offers great prospects for resistance breeding as well as elucidating the underlying molecular mechanism(s) of the resistance.

International audience; The generalist predator Orius laevigatus (Fieber) (Hemiptera: Anthocoridae) is a key natural enemy of various arthropods in agricultural and natural ecosystems. Releases of this predator are frequently carried out, and it is included in the Integrated Pest Management (IPM) programs of several crops. The accurate assessment of the compatibility of various pesticides with predator activity is key for the success of this strategy. We assessed acute and sublethal toxicity of 14 pesticides on O. laevigatus adults under laboratory conditions. Pesticides commonly used in either conventional or organic farming were selected for the study, including six biopesticides, three synthetic insecticides, two sulfur compounds and three adjuvants. To assess the pesticides' residual persistence, the predator was exposed for 3 d to pesticide residues on tomato sprouts that had been treated 1 h, 7 d or 14 d prior to the assay. The percentage of mortality and the sublethal effects on predator reproductive capacity were summarized in a reduction coefficient (E-x) and the pesticides were classified according to the IOBC (International Organization for Biological Control) toxicity categories. The results showed that the pesticides greatly differed in their toxicity, both in terms of lethal and sub lethal effects, as well as in their persistence. In particular, abamectin was the most noxious and persistent, and was classified as harmful up to 14 d after the treatment, causing almost 100% mortality. Spinosad, emamectin, metaflumizone were moderately harmful until 7 d after the treatment, while the other pesticides were slightly harmful or harmless. The results, based on the combination of assessment of acute mortality, predator reproductive capacity pesticides residual and pesticides residual persistence, stress the need of using complementary bioassays (e.g. assessment of lethal and sublethal effects) to carefully select the pesticides to be used in IPM programs and appropriately time the pesticides application (as function of natural enemies present in crops) and potential releases of natural enemies like O. laevigatus. (C) 2012 Elsevier Ltd. All rights reserved.

Plant responses induced by zoophytophagous plant bugs (Miridae) have not been thoroughly studied. Here, we show that three different zoophytophagous predators (Nesidiocoris tenuis, Macrolophus pygmaeus and Dicyphus maroccanus) have different capacities for the induction of responses in tomato plants, resulting in varying degrees of attractiveness of the plants to pests and natural enemies. Tomato plants punctured by N. tenuis were less attractive to the whitefly Bemisia tabaci and to the lepidopteran Tuta absoluta. In contrast, tomato plants punctured by M. pygmaeus and D. maroccanus were not able to repel B. tabaci and, more interestingly, became more attractive to T. absoluta. The ability of N. tenuis to make tomato plants less attractive to B. tabaci was attributed to the activation of the abscisic acid (ABA) signaling pathway, which was only up-regulated in plants punctured by N. tenuis. However, the phytohormones involved in the behavioral responses of T. absoluta could not be identified; therefore, further studies are required. Additionally, all three zoophytophagous mirid predators activated jasmonic acid (JA) signaling pathways, which resulted in the parasitoid Encarsia formosa being attracted to tomato plants. Here, the implications of these results on the efficacy of these three predators as biocontrol agents are discussed. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under the Grant agreement n°265865 and by the Spanish Ministry of Science and Innovation (AGL2011-30538-C03) and the Conselleria d’Agricultura, Pesca i Alimentació de la Generalitat Valenciana. The authors thank Javier Calvo (KOPPERT BS) for supplying the insects and Universitat Jaume I-SCIC for providing technical support.

Plants infected with pathogens often attract the pathogens' vectors, but it is not clear if this is advantageous to the vectors. We therefore quantified the direct and indirect (through the host plant) effects of a pathogen on its vector. A positive direct effect of the plant-pathogenic Tomato spotted wilt virus on its thrips vector (Frankliniella occidentalis) was found, but the main effect was indirect; juvenile survival and developmental rate of thrips was lower on pepper plants that were damaged by virus-free thrips than on unattacked plants, but such negative effects were absent on plants that were damaged and inoculated by infected thrips or were mechanically inoculated with the virus. Hence, potential vectors benefit from attacking plants with virus because virus-infected plants are of higher quality for the vector's offspring. We propose that plant pathogens in general have evolved mechanisms to overcome plant defences against their vectors, thus promoting pathogen spread

We have developed a novel strategy for the introduction of durable insect resistance in crops. This strategy was based on intervention in the natural relationship between plants and insects. For many insects, including pests such as thrips (Frankliniella occidentalis), the flower is an important factor in their life cycle, serving either as a food source or as a place for mating. The insects are attracted to the flower by scent, which is mainly produced by the petals, and by the bright colour of these floral organs. We therefore anticipated that removal or changing the identity of the petals would significantly reduce the attractiveness of the flower to thrips. To test this hypothesis, we used cucumber as a model species because most modern varieties are parthenocarpic, in which the fruit develops without fertilization. The cucumber mutant green petals, in which the petals are homeotically transformed into green sepals, was particularly useful for this study. The susceptibility of the cucumber plants to damage by thrips was determined by recording thrip numbers and by measuring leaf damage. Large differences were observed when greenhouse compartments with either wild-type or green petal mutant plants were compared. The rate of population growth of the insects on the mutant plants was significantly reduced and the leaves were almost undamaged. These results demonstrate that alterations in the structure of flowers may interfere with the life cycle of insects, providing the means for a novel and natural strategy for obtaining insect resistance.

Orius insidiosus is a generalist predator for which diet influences important biological traits like reproduction and predation. We tested the effects of different diets alone or in combination on reproduction, longevity and predation capacity of this predator. The diets tested were: no food (control); pollen; Frankliniella occidentalis (Pergande) nymphs and adults; F. occidentalis nymphs and adults and pollen; Anagasta kuehniella (Zeller) eggs; A. kuehniella eggs and pollen; A. kuehniella eggs; F. occidentalis nymphs and adults and A. kuehniella eggs, F. occidentalis nymphs and adults and pollen. The pre-oviposition period was shortest when the diet consisted of pollen and prey (A. kuehniella and/or F. occidentalis), of the two prey species together or of only A. kuehniella eggs. The highest values for the length of the oviposition period (50.1, 48.0, 46.3 and 46.1 days), daily fecundity (3.8, 3.9, 4.0 and 4.2 eggs/female/day), total fecundity (190.3, 187.7 185.2 and 193.6 eggs/female) and longevity (52.1, 49.9, 48.7 and 48.0 days) were found with diets consisting of only A. kuehniella eggs. Pollen did not improve any of the performance parameters of the predator when offered exclusively or as a complementary food. The results show that selection of a proper diet can strongly improve reproduction, longevity and predation capacity of O. insidiosus. An important finding is that A. kuehniella eggs, which can easily be produced in large quantities, are an excellent factitious prey for mass production of O. insidiosus.

The effect of moisture source and diet on the development and reproduction of the pirate bugs, Orius thripoborus (Hesse) and Orius naivashae (Poppius) (Hemiptera: Anthocoridae) was examined in the laboratory. Both species had been collected in and around sugarcane fields in South Africa. Supplementing eggs of the flour moth Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) with a green bean pod as a moisture source yielded better nymphal survival and faster development, as compared with free water encapsulated in Parafilm, suggesting that the predators may extract extra nutrients from the bean pod. The impact of two factitious foods and moist honey bee pollen on developmental and reproductive parameters of both predators was also investigated. The overall performance of both Orius species on E. kuehniella eggs and cysts of brine shrimp, Artemia franciscana Kellogg (Crustacea: Artemiidae) was better than on pollen. Nonetheless, a pollen diet alone allowed 66 and 78% of the nymphs of O. thripoborus and O. naivashae, respectively, to reach adulthood. Overall, developmental and reproductive performance of O. thripoborus on the tested diets was superior to that of O. naivashae. The implications of these findings for the mass production of these predators and their potential role in biological control programs in southern Africa are discussed.

1. Indirect interactions between populations of different prey species mediated by a shared predator population are known to affect prey dynamics.2. Depending on the temporal and spatial scale, these indirect interactions may result in positive (apparent mutualism), neutral or negative effects (apparent competition) of the prey on each other’s densities. Although there is ample evidence for the latter, evidence for apparent mutualism is scarce.3. The effectiveness of using one species of predator for biological control of more than one pest species depends on the occurrence of such positive or negative effects.4.We used an experimental system consisting of the two prey species Western flower thrips (Franklineilla occidentalis Pergande) and greenhouse whitefly (Trialeurodes vaporariorum Westwood) and a shared predator, the phytoseiid mite Amblyseius swirskii Athias-Henriot. We released all three species on the same plant and studied their dynamics and distribution along rows of plants.5. We expected that the more mobile prey species (thrips) would escape temporarily in the presence of the other prey species (whitefly) by dispersing from plants with the predator. The predator was expected to disperse slower in the presence of two prey species because of the higher availability of food. 6. Evidence was found for slower dispersal of predators and short-term escape of thrips from predation when whiteflies were present, thus confirming the occurrence of short-term apparent mutualism.7. The apparent mutualism resulted in a cascade to the first trophic level: a higher proportion of fruits was damaged by thrips in the presence of whiteflies.8. We conclude that apparent mutualism can be an important phenomenon in population dynamics, and can significantly affect biological control of pest species that share a natural enemy.

Tomato spotted wilt virus (TSWV) (genus Tospovirus, family Bunyaviridae) was first reported in Greece during 1972 (3) and currently is widespread in the central and northern part of the country infecting several cultivated and wild plant species (1,2). In June 2006, virus-like symptoms similar to those caused by TSWV were observed on sweet honey leaf (Stevia rebaudiana (Bertoni) Bertoni, [synonym Eupatorium rebaudianum Bertoni], family Asteraceae) plants in an experimental field in the prefecture of Kilkis and on potato (Solanum tuberosum, family Solanaceae) plants growing close to tobacco in the prefecture of Kozani in northern Greece. Diseased S. rebaudiana plants expressed chlorotic and necrotic rings and line patterns on systemically infected leaves and occasionally a general chlorosis or dwarfing of the plant. Potato plants expressed only necrotic rings or lesions and a mild plant dwarfing. Seven percent of the S. rebaudiana plants, but only 0.1% of the potato plants, were showing symptoms. TSWV was detected by ELISA using polyclonal antisera in all symptomatic plants of both species, but those plants tested negative for Potato Y virus (PVY), Cucumber mosaic virus (CMV), Alfalfa mosaic virus (AMV), and Potato leafroll virus (PLRV); all viruses known to occur in these areas. Sap from symptomatic plants was used to mechanically inoculate Petunia × hybrida cv. Blue magic, Nicotiana tabacum cvs. Samsun NN and Basmas, N. benthamiana, N. glutinosa, N. rustica, Datura stramonium, and Physalis floridana. Sap from both S. rebaudiana and potato produced typical symptoms of TSWV on the diagnostic test plants; all Nicotiana species and cultivars, as well as D. stramonium and P. floridana, reacted with chlorotic and necrotic lesions on the inoculated leaves followed by systemic mosaic and mottling of the leaves. None of the isolates produced systemic infection on P. × hybrida. Adult thrips, identified as Thrips tabaci, were collected from infected plants of both hosts in the field and determined to be infected with TSWV by the petunia leaf disc method (4). Symptoms observed in the field on both hosts where reproduced in the laboratory after infestation of healthy plants with TSWV-infected individuals from a tobacco population of T. tabaci. To our knowledge, this is the first official report of a TSWV infection in S. rebaudiana. Potato is a known host for TSWV, however, to our knowledge, this is the first natural infection detected in Greece. References: (1) E. K. Chatzivassiliou et al. Ann. Appl. Biol. 137:127, 2000. (2) E. K. Chatzivassiliou et al. Plant Dis. 85:40, 2001. (3) J. P. Tsakiridis and G. V. Gooding, Jr. Phytopathol. Mediterr. 11:42, 1972. (4) I. Wijkamp and D. Peters. Phytopathology 83:986,1993.

Ten predatory mite species, all phytoseiids, were evaluated for control of western flower thrips (WFT), Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), on greenhouse cucumber. This study was done to further improve biological control of thrips on this crop. Neoseiulus cucumeris (Oudemans) is at present used for biological control of thrips in greenhouses. Compared to this species, Typhlodromalus limonicus (Garman & McGregor), Typhlodromips swirskii (Athias-Henriot) and Euseius ovalis (Evans) reached much higher population levels resulting in a significantly better control of thrips. T. limonicus was clearly the best predator of WFT. Also Euseius scutalis (Athias-Henriot) increased to higher populations levels than N. cucumeris, but without controlling the thrips, probably because of an unequal distribution of this predator on the plant. Iphiseius degenerans (Berlese), Neoseiulus barkeri (Hughes), Euseius finlandicus (Oudemans) and Typhlodromus pyri (Scheuten) did not establish better than N. cucumeris. A non-diapausing exotic strain of N. cucumeris did not differ from the North European strain. The best performers in this study were all of sub-tropical origin. T. limonicus, T. swirskii and E. ovalis have good potentials for controlling not only thrips but also whiteflies. Factors affecting the efficacy of phytoseiids on greenhouse cucumbers are discussed.

Plants infected with pathogens often attract the pathogens’ vectors, but it is not clear if this is advantageous to the vectors. We therefore quantified the direct and indirect (through the host plant) effects of a pathogen on its vector. A positive direct effect of the plant‐pathogenic Tomato spotted wilt virus on its thrips vector (Frankliniella occidentalis) was found, but the main effect was indirect; juvenile survival and developmental rate of thrips was lower on pepper plants that were damaged by virus‐free thrips than on unattacked plants, but such negative effects were absent on plants that were damaged and inoculated by infected thrips or were mechanically inoculated with the virus. Hence, potential vectors benefit from attacking plants with virus because virus‐infected plants are of higher quality for the vector's offspring. We propose that plant pathogens in general have evolved mechanisms to overcome plant defences against their vectors, thus promoting pathogen spread.

We have developed a novel strategy for the introduction of durable insect resistance in crops. This strategy was based on intervention in the natural relationship between plants and insects. For many insects, including pests such as thrips (Frankliniella occidentalis), the flower is an important factor in their life cycle, serving either as a food source or as a place for mating. The insects are attracted to the flower by scent, which is mainly produced by the petals, and by the bright colour of these floral organs. We therefore anticipated that removal or changing the identity of the petals would significantly reduce the attractiveness of the flower to thrips. To test this hypothesis, we used cucumber as a model species because most modern varieties are parthenocarpic, in which the fruit develops without fertilization. The cucumber mutant green petals, in which the petals are homeotically transformed into green sepals, was particularly useful for this study. The susceptibility of the cucumber plants to damage by thrips was determined by recording thrip numbers and by measuring leaf damage. Large differences were observed when greenhouse compartments with either wild-type or green petal mutant plants were compared. The rate of population growth of the insects on the mutant plants was significantly reduced and the leaves were almost undamaged. These results demonstrate that alterations in the structure of flowers may interfere with the life cycle of insects, providing the means for a novel and natural strategy for obtaining insect resistance.

Endophytic fungi, which live within host plant tissues without causing any visible symptom of infection, are important mutualists that mediate plant-herbivore interactions. Thrips tabaci (Lindeman) is one of the key pests of onion, Allium cepa L., an economically important agricultural crop cultivated worldwide. However, information on endophyte colonization of onions, and their impacts on the biology of thrips feeding on them, is lacking. We tested the colonization of onion plants by selected fungal endophyte isolates using two inoculation methods. The effects of inoculated endophytes on T. tabaci infesting onion were also examined. Seven fungal endophytes used in our study were able to colonize onion plants either by the seed or seedling inoculation methods. Seed inoculation resulted in 1.47 times higher mean percentage post-inoculation recovery of all the endophytes tested as compared to seedling inoculation. Fewer thrips were observed on plants inoculated with Clonostachys rosea ICIPE 707, Trichoderma asperellum M2RT4, Trichoderma atroviride ICIPE 710, Trichoderma harzianum 709, Hypocrea lixii F3ST1 and Fusarium sp. ICIPE 712 isolates as compared to those inoculated with Fusarium sp. ICIPE 717 and the control treatments. Onion plants colonized by C. rosea ICIPE 707, T. asperellum M2RT4, T. atroviride ICIPE 710 and H. lixii F3ST1 had significantly lower feeding punctures as compared to the other treatments. Among the isolates tested, the lowest numbers of eggs were laid by T. tabaci on H. lixii F3ST1 and C. rosea ICIPE 707 inoculated plants. These results extend the knowledge on colonization of onions by fungal endophytes and their effects on Thrips tabaci. BMZ/GIZ/11.7860.7-001.00 BMZ/GIZ/11.7860.7-001.00