Selection of insectary plants for the conservation of biological control agents of aphids and thrips in fruit orchards

This study evaluated the potential of flowering plant species naturally occurring to promote the conservation and early establishment of key natural enemies of aphids and thrips in apple and peach orchards. Flowering plants present in the North East of Spain, a main fruit production area in Europe, were sampled to determine their flowering period and to identify potential natural enemies present on each plant species. Thirty-six plant species were found blooming from early March to late May and provided an array of flowers that might ensure food resources for natural enemies. Among them, six species – Eruca vesicaria (L.) Cav., Cardaria draba (L.) Desv., Euphorbia serrata (L.) S.G. Gmel., Malva sylvestris L., Anacyclus clavatus (Desf.) Pers. and Diplotaxis erucoides (L.) DC. – hosted a high diversity of potential natural enemies of aphids and thrips. Their blooming started early in the season and lasted for several sampling weeks and they were widely distributed. Moreover, they had available nectar even in those species with protected nectaries. Therefore, these plant species can be considered as promising candidates for inclusion in the ecological infrastructure designed for fruit orchards in the study area to promote the conservation of the biological control agents of aphids and thrips.info:eu-repo/semantics/acceptedVersio

Models for the practitioner: Predicting the efficient biocontrol of Tuta absoluta under different management scenarios

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most destructive pests of solanaceous crops. One possible biological control strategy is the augmentative release of parasitoids. However, parasitoid intervention efficacy is highly sensitive to the release timing and intensity. Virus-based biopesticides are additional control means since they are highly selective and can be combined with natural enemies. We developed a stage-structured population model, validated with results from a semi-field experiment, to investigate and predict the population dynamics of the pest T. absoluta and one of its parasitoids, Necremnus tutae Ribes & Bernardo (Hymenoptera: Eulophidae). The aim of the study was to assess the best release parameters of N. tutae to control the pest in four different management scenarios: without any other control method, with a biopesticide (PhopGV, Baculoviridae), with the natural presence of the parasitoid, and when combining the natural presence of the parasitoid with a biopesticide. Moreover, in each scenario, two growing seasons of different lengths were compared. To achieve the same control level, 3–45% fewer parasitoids are necessary in a long growing season than in a shorter one. Biopesticide applications reduce the number of required parasitoids by 66% and 78%, whereas the natural presence of parasitoids reduces it by 11% and 17% for short and long growing seasons, respectively. On average, with biopesticide application, the parasitoid intervention can be delayed by a month and remains efficient. These findings highlight the importance of mathematical models in applied pest management drawing precise predictions crucial for efficient control.JA was financed by the CERCA Programme of the Generalitat de Catalunya.info:eu-repo/semantics/publishedVersio

Attraction of Aphidius ervi (Hymenoptera: Braconidae) and Aphidoletes aphidimyza (Diptera: Cecidomyiidae) to Sweet Alyssum and Assessment of Plant Resources Effects on their Fitness

The green peach aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) is one of the most economically important aphid species affecting crops worldwide. Since many natural enemies of this aphid have been recorded, biological control of this pest might be a viable alternative to manage it. Selected plant species in field margins might help to provide the natural enemies with food sources to enhance their fitness. This study aimed to investigate if sweet alyssum, Lobularia maritima (L.) (Brassicaceae), is a potential food source for the parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae) and the predator Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae), and whether this flower could contribute to enhance the biological control of M. persicae. Volatiles produced by alyssum, with and without flowers, attracted both natural enemies. This attractiveness to alyssum flowers was disrupted when compared with peach shoots recently infested with a relatively low number of aphids. When aphids were absent, parasitoids exposed to alyssum survived longer than those that fed on a sugar solution or on water. In the case of the predator, alyssum flowers did not benefit longevity since the nectaries were inaccessible to females. However, our results provide evidence that A. aphidimyza would be able to feed on nectar if accessible. The floral resource did not improve the reproductive capacity of the two natural enemies, but the 10% sugar solution increased the egg load of the predator. Provision of other sugar resources, such as flowers with exposed nectaries and extra floral nectar may also be a viable option to improve the biological control of M. persicae.info:eu-repo/semantics/acceptedVersio

Tuta absoluta (Lepidoptera: Gelechiidae) success on common solanaceous species from California tomato production areas

Tuta absoluta (Meyrick) is a devastating pest of tomato that has invaded many regions of the world. To date, it has not been detected in North America, but the pest reached Costa Rica in 2014 and seriously threatens the southern, southwestern, and western United States including California. Although the primary host of T. absoluta is tomato, several other species of Solanaceae may serve as alternative hosts. In our study, we aimed to assess the potential risk that other solanaceous crops and wild species that are often present in and around California tomato fields could serve as hosts. To accomplish this, we conducted greenhouse and laboratory studies to determine whether two common cultivars of fresh market tomato, two common cultivars of tomatillo, and the wild plants, Solanum nigrum L., Solanum sarrachoides (Sendtner), and Datura stramonium L., are suitable hosts for reproduction and development of the pest. According to our results, D. stramonium and tomatillo were unable to sustain T. absoluta larval development in either greenhouse studies or laboratory studies, and therefore, they are not likely to contribute to T. absoluta establishment during an invasion. On the contrary, the two other solanaceous weeds, S. nigrum and S. sarrachoides, share a similar potential as tomato to be reproductive and developmental hosts of T. absoluta, and might play an important role in the establishment of the pest in California.info:eu-repo/semantics/acceptedVersio

El control biològic en els cultius hortícoles a Catalunya

info:eu-repo/semantics/publishedVersio

Selection of flowering plants to enhance the biological control of Tuta absoluta using parasitoids

The tomato moth Tuta absoluta is an important pest of tomato crops. To enhance biological control services, our study aims to ascertain the effect of potential insectary plants (Achillea millefolium, Calendula officinalis, Fagopyrum esculentum, Lobularia maritima, Ononis natrix, Sinapis alba, and Tagetes patula) as nutrient-providers to facilitate the installation of T. absoluta parasitoids (Necremnus tutae, Stenomesius nr. japonicus, and Bracon nr. nigricans) without encouraging the pest. Our results showed that different flowers provide different benefits in terms of survival and egg load for different parasitoid species, and that the benefit of these flowers for T. absoluta females was low. Being N. tutae the most abundant and widespread parasitoid, selection of flowers might target this parasitoid. However, the provision of a flower mixture may be more advantageous than selecting only one species because they may contribute to enhance a broader guild of parasitoid wasps.info:eu-repo/semantics/acceptedVersio

Característiques físiques i químiques a determinar en els compostos fets amb fangs residuals per tal d'ésser utilitzats com a substrats

Hi ha una sèrie d'activitats humanes que comporten 1'aparició de subproductes contaminants. En particular ens hem centrat en els fangs residuals de les industries papereres i de les depuradores d'aigües urbanes. Aquests productes presenten problemes d'eliminació pel gran volum que se n'obté, i per llur contingut en substàncies nocives. D'altra banda l'horticultura ornamental és un sector en expansió amb una demanda creixent de substrats. El substrat més utilitzat en 1'actualitat és la torba, que té un preu molt alt. Observem doncs la necessitat de trobar materials alternatius més barats. Això ens ha impulsat a estudiar la viabilitat dels fangs com a substrats. La utilització d'aquests materials requereix un condicionament previ, que és el que hom fa mitjançant el procés anomenat compostatge (fermentació aeròbica i termòfila d'un o més productes orgànics per a eliminar o minvar llur capacitat contaminant). El producte final és el compost, el qual ha de tenir unes propietats físico-químiques adients. Resulta imprescindible un seguiment de 1'evolució del compostatge i saber quan aquest ja ha acabat. Aquest seguiment comporta el control d'uns paràmetres químics (concentració en macro- i micronutrients i metalls pesants, contingut i qualitat de la matèria orgànica... ), paràmetres físico-químics (pH, CE, CBC...) i físics (densitat real i aparent, capacitat de retenció d'aigua... ). A més, han estat fetes proves de creixement de plantes ornamentals per tal d'estudiar l'aptitud del producte com a substrat

Banker plants and landscape composition influence colonisation precocity of tomato greenhouses by mirid predators

Conservation biological control involves manipulation of the environment to enhance the effectiveness of natural enemies in controlling crop pests. In this study, we combined historical data, sticky trap sampling of tomato greenhouses and beat sampling of adjacent vegetation to identify which greenhouse characteristics, habitat management practices and landscape features favour an early colonisation of tomato greenhouses by the key mirid predator Macrolophus pygmaeus and its establishment in NE Spain. Results show that landscape composition and the use of Calendula officinalis banker plants inside the greenhouse are key factors. In general, greater amounts of herbaceous semi-natural cover at the landscape scale promoted M. pygmaeus colonisation, while the use of C. officinalis banker plants encouraged M. pygmaeus colonisation independently of the landscape context. We identified host plants adjacent to tomato greenhouses that sustain M. pygmaeus populations; however, they did not have a major effect on M. pygmaeus colonisation compared to larger landscape and banker plant effects. Early colonisation of greenhouses by this predator species also translated into lower accumulated incidence of pests at the end of the sampling period. This study demonstrates the importance of active habitat management practices in promoting the early arrival of M. pygmaeus in greenhouses with delayed spontaneous colonisation.info:eu-repo/semantics/acceptedVersio

Protected agriculture matters: Year-round persistence of Tuta absoluta in China where it should not

Tuta absoluta (Lepidoptera: Gelechiidae) originates from the South American tropics but has become a major invasive pest of tomato and other Solanaceae crops worldwide. Agricultural protected facilities (APFs) such as greenhouses and plastic tunnels may provide thermal conditions that allow the survival of T. absoluta in temperate zones with cold winters. In this study, a CLIMEX model was used to investigate the dual effects of increasing use of APFs and climate warming on the potential distribution and seasonal dynamics of T. absoluta in China. Our model showed that the northern boundary for year-round population persistence in China, ignoring APFs, was approximately 30°N, covering about 21% of China’s area suitable under current climate. The modelled suitable area increased to 31% and northern boundary for year-round population persistence shifted to 40°N in 2080 under global warming. When APF refuges are included, the potential suitable area was 78% under the current climate and 79% under global warming. This suggests that, in the future, the increasing use of APFs will increase the areas at risk of T. absoluta invasion significantly more than global warming because APFs effectively protect T. absoluta from harsh northern winters. In addition, vegetable production in surrounding open fields will be at risk of invasion during milder seasons when APFs are opened and T. absoluta can disperse. Therefore, the micro-climate of APFs should be considered as part of the invasion process, and Integrated Pest Management should be simultaneously implemented inside and outside APFs for the rational management T. absoluta.This work was supported by National Key R&D program of China (2021YFD1400200). CERCA Program / Generalitat de Catalunya provided funding to JA, and ND was funded in part by the Horizon Europe project ADOPT-IPM (n◦101060430).info:eu-repo/semantics/publishedVersio

Resolving the taxonomic status of potential biocontrol agents belonging to the neglected genus lipolexis Förster (Hymenoptera, Braconidae, Aphidiinae) with descriptions of six new species

Lipolexis is a small genus in the subfamily Aphidiinae represented by one species in Europe (Lipolexis gracilis Förster) and by four in Asia (Lipolexis wuyiensis Chen, L. oregmae Gahan, L. myzakkaiae Pramanik and Raychaudhuri and L. pseudoscutellaris Pramanik and Raychaudhuri). Although L. oregmae is employed in biological control programs against pest aphids, the last morphological study on the genus was completed over 50 years ago. This study employs an integrative approach (morphology and molecular analysis (COI barcode region)), to examine Lipolexis specimens that were sampled worldwide, including specimens from BOLD database. These results establish that two currently recognized species of Lipolexis (L. gracilis, L. oregmae) are actually a species complex and also reveal phylogenetic relationships within the genus. Six new species are described and a global key for the identification of Lipolexis species is provided.info:eu-repo/semantics/publishedVersio