Ground-covers affect the activity density of ground-dwelling predators and their impact on the Mediterranean fruit fly, Ceratitis capitata

Three developmental stages of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), can be found in the soil (late third instar larvae, pupae, and teneral adults). These stages are susceptible to predation by generalist ground-dwelling predators. Our objectives have been to investigate the association between ground cover management (bare soil, a seeded cover of Festuca arundinacea and a mulch of straw), the emergence success of C. capitata, and the activity density of the most important groups of ground-dwelling predators (spiders, beetles, ants and earwigs). As expected, C. capitata emergence was lower in a seeded cover of Festuca arundinacea (FA) and a mulch of straw (M) (10.2%) relative to bare soil (BS) (13.2%). This was related to higher diversity and activity density of ground-dwelling predators in FA and M compared to BS. The contribution of the ground-dwelling predators considered in this study to this reduction highlights the key role of beetles, earwigs and, to a lesser extent, ants, while the contribution of the most abundant group of ground-dwelling predators, spiders, remains unclear. Ground covers appear as a strong and sustainable conservation biological control method that should be taken into consideration for the management of C. capitata populations.Funding for open access charge: CRUE-Universitat Jaume IOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Financial support has been provided by the European Union’s Horizon 2020 Program for Research and Innovation grant number 818184 (FF-IPM) and PRIMA grant number 1812 (PLANT-B).We thank M. Piquer (UJI) and A. Benages (COCALNI, Cooperativa Citrícola de Les Alqueries) for technical support and provision of the experimental orchard, respectively. Financial support has been provided by the European Union’s Horizon 2020 Program for Research and Innovation grant number 818184 (FF-IPM) and PRIMA grant number 1812 (PLANT-B)

Zoophytophagous mites can trigger plant‐genotype specific defensive responses affecting potential prey beyond predation: the case of Euseius stipulatus and Tetranychus urticae in citrus

Background Zoophytophagous predators can trigger plant defenses affecting prey populations beyond predation. Euseius stipulatus is a presumed zoophytophagous phytoseiid common in citrus. The response of citrus to one of its potential prey, Tetranychus urticae, is genotype dependent, with Citrus reshni and C. aurantium exhibiting extreme susceptibility and resistance, respectively. Volatile blends produced upon infestation affected the behavior of these two mites. We wondered whether E. stipulatus could trigger similar responses. Results Euseius stipulatus triggered genotype‐dependent defense responses in citrus. Whereas C. aurantium upregulated the Jasmonic Acid, Salicylic Acid and flavonoids defensive pathways, C. reshni upregulated JA only. Likewise, different volatile blends were induced. These blends were exploited by E. stipulatus to select less‐defended plants (i.e., those in which higher pest densities are expected) and, interestingly, did not prevent T. urticae from choosing E. stipulatus‐infested plants. To the best of our knowledge, this is the first time that this type of response has been described for a zoophytophagous phytoseiid. Conclusion The observed responses could affect herbivore populations through plant‐mediated effects. Although further research is needed to fully characterize them and include other arthropods in the system, these results open opportunities for more sustainable and effective pest control methods (i.e., combining semiochemicals and biological control

Molecular characterization of Cardinium, Rickettsia, Spiroplasma and Wolbachia in mite species from citrus orchards

Tetranychidae spider mites are considered key citrus pests in some production areas, especially Tetranychus urticae Koch. Over the past decades, pesticide overuse seems to have promoted T. urticae population selection in citrus orchards. However, the microbiota has also been pointed out as a plausible explanation for population structure or plant host specialisation observed in several arthropod species. In this work, we have determined the incidence of Cardinium, Rickettsia, Spiroplasma and Wolbachia as representatives of major distorter bacteria genera in Aplonobia histricina (Berlese), Eutetranychus banksi (McGregor), Eutetranychus orientalis (Klein), Panonychus citri (McGregor), Tetranychus evansi Baker and Pritchard, Tetranychus turkestani Ugarov and Nikolskii, and T. urticae populations from Spanish citrus orchards. Only Wolbachia was detected by PCR. The multilocus alignment approach and phylogenetic inference indicated that all detected Wolbachia belong to supergroup B. The deep analysis of each 16S rDNA, ftsZ and wsp gene sequences allowed identifying several phylogenetically diferent Wolbachia sequences. It probably indicates the presence of several diferent races or strains, all of them belonging to supergroup B. The wsp sequence typing analysis unveiled the presence of the two already identifed alleles (61 and 370) and allowed to contribute with fve new alleles, supporting the presence of diferent but related B-races in the studied mite populations. The results are discussed and related to T. urticae population structure, previously observed in Spanish citrus orchards

The olfactive responses of Tetranychus urticae natural enemies in citrus depend on plant genotype, prey presence, and their diet specialization

[EN] Sour orange, Citrus aurantium, displays higher constitutive and earlier inducible direct defenses against the two-spotted spider mite, Tetranychus urticae, than Cleopatra mandarin, Citrus reshni. Moreover, herbivore-induced plant volatiles (HIPVs) produced by sour orange upon infestation can induce resistance in Cleopatra mandarin but not vice versa. Because the role of these HIPVs in indirect resistance remains ignored, we have carried out a series of behavioral assays with three predatory mites with different levels of specialization on this herbivore, from strict entomophagy to omnivory. We have further characterized the volatile blend associated with T. urticae, which interestingly includes the HIPV methyl salicylate, as well as that produced by induced Cleopatra mandarin plants. Although a preference for less defended plants with presumably higher prey densities (i.e., C. reshni) was expected, this was not always the case. Because predators' responses changed with diet width, with omnivore predators responding to both HIPVs and prey-related odors and specialized ones mostly to prey, our results reveal that these responses depend on plant genotype, prey presence and predator diet specialization. As the different volatile blends produced by infested sour orange, induced Cleopatra mandarin and T. urticae itself are attractive to T. urticae natural enemies but not to the herbivore, they may provide clues to develop new more sustainable tools to manipulate these agriculturally relevant species.The research leading to these results was partially funded by the Spanish Ministry of Economy and Competitiveness (AGL2014-55616-C3; AGL2015-64990-2R). The authors thank M. Piquer (UJI) for technical assistance. MC received a pre-doctoral fellowship from the Spanish Ministry of Economy and Competitiveness (BES-2015-074570), and MP was the recipient of a research fellowship from INIA, Spain (subprogram DOC INIA-CCAA).Cabedo López, M.; Cruz-Miralles, J.; Vacas, S.; Navarro-Llopis, V.; Pérez-Hedo, M.; Flors, V.; Jaques, JA. (2019). The olfactive responses of Tetranychus urticae natural enemies in citrus depend on plant genotype, prey presence, and their diet specialization. Journal of Pest Science. 92(3):1165-1177. https://doi.org/10.1007/s10340-019-01107-7S1165117792

From virus resistance to arthropod susceptibility

Resumen de la ponencia presentada en el Annual Meeting on Crop-arthropod-microorganism interactions (CAMo), celabrado en Ljubljana, January 31st to February 2nd, 201

Host plant scent mediates patterns of attraction/repellence among predatory mites

[EN] In mite communities, behavioral and foraging decisions of individuals rely on semiochemicals that they gather from the environment, which contain odors from plants, herbivores, and predators. Because herbivorous mites commonly co-occur with several species of phytoseiid predatory mites, which may engage in intraguild predation (IGP), predator mite decision-making relies on their ability to recognize odors signaling the presence of the herbivore but also that of potential competitors/predators. Here the odor-related foraging decisions of three predatory mites, Euseius stipulatus (Athias-Henriot), Neoseiulus californicus (McGregor) and Phytoseiulus persimilis (Athias-Henriot) (Mesostigmata: Phytoseiidae), which co-occur in citrus, compete for the herbivore Tetranychus urticae Koch (Prostigmata: Tetranychidae), and can engage in IGP were investigated. The composition of the volatile blends associated with the three predators was characterized. Moreover, the effect of these odors on the predators foraging decisions was measured. Results revealed that (1) the volatile signature of the three predatory mites is species specific, (2) the predators¿ foraging behavior is affected by heterospecific predator odors, and (3) predator responses strongly depend on the host plant: mutual attraction and mutual repellence occurred in Cleopatra mandarin and sour orange, respectively. These findings have important consequences for the management of systems where these species occur. The odor blends that make predators that share pest species as prey avoid each other could be used to improve pest control by minimizing undesired negative interactions among predator species, and by locally increasing predation risk on herbivore pest species.The authors thank M. Piquer (UJI) for technical assistance and J. Calvo (Koppert Biological Systems) for the supply of N. californicus and P. persimilis. This study was partially funded by the Spanish Research State Agency (research grants AGL2014-55616-C3, AGL2015-64990-2R, PID2019-103863RB-I00 and BES-2015-074570).Cruz-Miralles, J.; Cabedo-Lopez, M.; Guzzo, M.; Vacas, S.; Navarro-Llopis, V.; Ibáñez-Gual, MV.; Flors, V.... (2022). Host plant scent mediates patterns of attraction/repellence among predatory mites. Entomologia Generalis. 42(2):217-229. https://doi.org/10.1127/entomologia/2021/1237S21722942

The response of citrus plants to the broad mite Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae)

1. Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae) is a common polyphagous mite in tropical and subtropical areas and is considered as an important citrus pest. 2. To understand the response of citrus to P. latus infestation, we have characterized the volatile profile and the molecular defence mechanisms of two citrus genotypes, namely sour orange (Citrus aurantium) and Cleopatra mandarin (Citrus reshni), to P. latus infestation. These two species are important rootstocks for the citrus industry and display differential resistance to Tetranychus urticae Koch (Acari: Tetranychidae), with sour orange showing elevated levels of constitutive and induced resistance associated with the jasmonic acid (JA) pathway compared with Cleopatra mandarin. 3. P. latus infestation activated both the JA- and the salicylic acid-dependent pathways in sour orange but not in Cleopatra mandarin. However, this differential activation resulted in the production of similar volatile blends (a mixture of green leaf volatiles and aromatic compounds). 4. Contrary to T. urticae infestation, sour orange supported larger densities of P. latus than Cleopatra mandarin with similar injury levels. 5. Therefore, sour orange may be more tolerant to P. latus than Cleopatra mandarin.The research leading to these results was partially funded by the EU 7FP (C-IPM UNIFORCE) and the Spanish Ministry of Economy and Competitiveness (AGL2015-64990-2R). The authors thank M. Piquer (UJI) for technical assistance. MC received a pre-doctoral fellowship from the Spanish Ministry of Economy and Competitiveness (BES-2015-074570). No conflict of interest exists. This article does not contain any studies with human participants performed by any of the authors

Dataset: Plant-feeding may explain why the generalist predator Euseius stipulatus does better on less defended citrus plants but Tetranychus-specialists Neoseiulus californicus and Phytoseiulus persimilis do not

The generalist predator Euseius stipulatus (Athias-Henriot) and the Tetranychidae-specialist predators Neoseiulus californicus (McGregor) and Phytoseiulus persimilis Athias-Henriot play a key role in the regulation of Tetranychus urticae Koch in Spanish citrus orchards. Previous studies have shown that sour orange (Citrus aurantium L.) and Cleopatra mandarin (Citrus reshni hort. ex Tan.) display extreme resistance and susceptibility to T. urticae, respectively. When ofered a choice between these two genotypes infested by T. urticae, E. stipulatus preferred Cleopatra mandarin, whereas the specialists did not show any preference. The present study was undertaken to check whether these preferences could be related to the feeding of E. stipulatus on the host plant and/or to diferences in prey feeding on the two plants. Our results demonstrate that E. stipulatus is a zoophytophagous mite, which can engage in direct plant feeding in sour orange and Cleopatra mandarin, whereas neither N. californicus nor P. persimilis do so. Whereas Cleopatra mandarin provided a higher-quality prey/feeding substrate for E. stipulatus, which may be related to its phytophagy, no diferences were observed for the two specialists. As higher constitutive and faster inducible defense against T. urticae in sour orange relative to Cleopatra mandarin plants result in sour orange supporting lower T. urticae densities and plant damage, our results demonstrate that pest regulation by specialist natural enemies may be more efective when prey feed on better defended plants

ISARIC-COVID-19 dataset: A Prospective, Standardized, Global Dataset of Patients Hospitalized with COVID-19

The International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) COVID-19 dataset is one of the largest international databases of prospectively collected clinical data on people hospitalized with COVID-19. This dataset was compiled during the COVID-19 pandemic by a network of hospitals that collect data using the ISARIC-World Health Organization Clinical Characterization Protocol and data tools. The database includes data from more than 705,000 patients, collected in more than 60 countries and 1,500 centres worldwide. Patient data are available from acute hospital admissions with COVID-19 and outpatient follow-ups. The data include signs and symptoms, pre-existing comorbidities, vital signs, chronic and acute treatments, complications, dates of hospitalization and discharge, mortality, viral strains, vaccination status, and other data. Here, we present the dataset characteristics, explain its architecture and how to gain access, and provide tools to facilitate its use