Is emamectin benzoate effective against the different stages of Spodoptera exigua (Hübner) (Lepidoptera, Noctuidae)?

peer-reviewedThis work was partially supported by the Spanish Ministry of Science and Innovation (project AGL 2007-66130-C03-02 to P. Medina). F. Amor and P. Bengochea acknowledge the ministry of Education and Culture and the Technical University of Madrid (UPM) for the doctoral fellowships. Special thanks to Syngenta Agro S.A. for their support.The beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera, Noctuidae), is a major polyphagous pest in greenhouses and open fields worldwide and also a main problem in sweet pepper greenhouses. The effectiveness of the pesticide emamectin benzoate was tested in the laboratory on different stages of S. exigua using different concentrations and uptake routes. After dipping young (48-h-old) S. exigua eggs in emamectin benzoate at 0.5, 1 and 1.5 mg/L a.i. the chemical did not exhibit any ovicidal activity. There was, however, progressive neonate mortality at all concentrations, culminating at 72 hours after hatching, when 100% of the larvae from the treated young eggs died. Second and fourth instar S. exigua larvae did not exhibit significant mortality when exposed to the inert surfaces which were treated. In contrast, ingesting a diet contaminated with 0.5 mg/L a.i. of emamectin benzoate caused 100% mortality in L2 and L4 larvae 24 and 72 hours after ingestion, respectively. The LC50 value of the compound against L4 larvae that fed on sprayed sweet pepper leaves for 24 hours was 0.81 mg/L a.i.. When adults were fed on a solution of 0.5 mg/L a.i., there was a reduction in the female and male lifespan of 29.3% and 55.3%, respectively. Fecundity was reduced by more than 99%. These data suggest that emamectin benzoate is not only a useful insecticide when ingested by beet armyworm larvae but it also has ovolarvicidal and adult activity.Spanish Ministry of Science and Innovatio

Lethal and Sublethal Effects of Methoxyfenozide on the Development, Survival and Reproduction on of the Fall Armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

The lethal and sublethal effects of the ecdysone agonist methoxyfenozide on the fall armyworm, Spodoptera frugiperda (J. E. Smith), were investigated by feeding a methoxyfenozide-treated diet to fifth instars until pupation in doses corresponding to the LC10 and LC25 for the compound. Larval mortality reached 8% and 26% in the low and high concentration groups, respectively, on the seventh day of the experiment. A progressive larval mortality of 12% for the LC10 and 60% for the LC25 was observed before pupation. Treated larvae exhibited lower pupal weights, higher pupal mortality, presence of deformed pupae, and more deformed adults than untreated larvae. The incorporation of methoxyfenozide into the diet had a significant effect on the timing of larval development. The development period for males and females was about seven days longer than the controls for both concentrations tested. In contrast, the compound affected neither pupae nor adult longevity. Finally, S. frugiperda adults that resulted from fifth instars treated with methoxyfenozide were not affected in their mean cumulative number of eggs laid per female (fecundity), nor percentages of eggs hatched (fertility), or the sex ratio. Our results suggest that the combination of lethal and sublethal effects of methoxyfenozide may have important implications for the population dynamics of the fall armyworm

Dominansi Dan Diversitas Lamun Dan Makrozoobenthos Pada Musim Pancaroba Di Pantai Bama, Taman Nasional Baluran, Situbondo [Dominance and Diversity of Seagrass and Macrozoobenthos on Transition Season in Bama Beach, Baluran National Park, Situbondo]

Lamun merupakan tanaman berbiji terbuka yang mampu tumbuh dan beradaptasi dengan lingkungan bersalinitas tinggi serta dapat berasosiasi dengan benthos. Keberadaan lamun di perairan merupakan salah satu indikator tingkat kesuburan dan produktivitas perairan. Terdapat perbedaan dominansi antara musim hujan dan musim kemarau, sehingga enelitian ini bertujuan untuk mengidentifikasi dan menghitung dominansi dan keanekaragaman lamun dan makrozoobenthos pada musim pancaroba di Pantai Bama, TN Baluran, Situbondo. Metode penelitian yang digunakan yaitu line transect quadran dengan 5 line transek quadran yang masing-masingnya dipasang 5 plot transek. Ditemukan jenis lamun yang memiliki nilai kelimpahan tertinggi di Pantai Bama, TN Baluran pada musim pancaroba yaitu C. serrulata dengan nilai 48,90% , dan makrozoobenthos dari genus Holothuria dengan nilai 52,06%. Nilai Indeks dominansi (D) mengkategorikan Pantai Bama, TN Baluran dalam perairan dengan dominansi sedang. Sedangkan berdasarkan Indeks keanekaragaman (H\u27) mengkategorikan Pantai Bama, TN Baluran dalam perairan dengan keanekaragaman rendah. Musim peralihan berpengaruh terhadap jenis, kelimpahan relatif, indeks dominansi dan indeks keanekaragaman lamun dan makrozoobenthos di Pantai Bama, TN Baluran dibandingkan musim kemarau dan hujan. Perlu dilakukan survei secara berkala untuk mengetahui keanekaragaman organisme yang berkaitan dengan produktivitas perairan

Microglial amyloid beta clearance is driven by PIEZO1 channels

Background Microglia are the endogenous immune cells of the brain and act as sensors of pathology to maintain brain homeostasis and eliminate potential threats. In Alzheimer's disease (AD), toxic amyloid beta (A beta) accumulates in the brain and forms stiff plaques. In late-onset AD accounting for 95% of all cases, this is thought to be due to reduced clearance of A beta. Human genome-wide association studies and animal models suggest that reduced clearance results from aberrant function of microglia. While the impact of neurochemical pathways on microglia had been broadly studied, mechanical receptors regulating microglial functions remain largely unexplored. Methods Here we showed that a mechanotransduction ion channel, PIEZO1, is expressed and functional in human and mouse microglia. We used a small molecule agonist, Yoda1, to study how activation of PIEZO1 affects AD-related functions in human induced pluripotent stem cell (iPSC)-derived microglia-like cells (iMGL) under controlled laboratory experiments. Cell survival, metabolism, phagocytosis and lysosomal activity were assessed using real-time functional assays. To evaluate the effect of activation of PIEZO1 in vivo, 5-month-old 5xFAD male mice were infused daily with Yoda1 for two weeks through intracranial cannulas. Microglial Iba1 expression and A beta pathology were quantified with immunohistochemistry and confocal microscopy. Published human and mouse AD datasets were used for in-depth analysis of PIEZO1 gene expression and related pathways in microglial subpopulations. Results We show that PIEZO1 orchestrates A beta clearance by enhancing microglial survival, phagocytosis, and lysosomal activity. A beta inhibited PIEZO1-mediated calcium transients, whereas activation of PIEZO1 with a selective agonist, Yoda1, improved microglial phagocytosis resulting in A beta clearance both in human and mouse models of AD. Moreover, PIEZO1 expression was associated with a unique microglial transcriptional phenotype in AD as indicated by assessment of cellular metabolism, and human and mouse single-cell datasets. Conclusion These results indicate that the compromised function of microglia in AD could be improved by controlled activation of PIEZO1 channels resulting in alleviated A beta burden. Pharmacological regulation of these mechanoreceptors in microglia could represent a novel therapeutic paradigm for AD.Peer reviewe

Dynamic release of neuronal extracellular vesicles containing miR-21a-5p is induced by hypoxia

© 2022 The Authors. Journal of Extracellular Vesicles published by Wiley Periodicals, LLC on behalf of the International Society for Extracellular Vesicles. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Hypoxia induces changes in the secretion of extracellular vesicles (EVs) in several non-neuronal cells and pathological conditions. EVs are packed with biomolecules, such as microRNA(miR)-21-5p, which respond to hypoxia. However, the true EV association of miR-21-5p, and its functional or biomarker relevance, are inadequately characterised. Neurons are extremely sensitive cells, and it is not known whether the secretion of neuronal EVs and miR-21-5p are altered upon hypoxia. Here, we characterised the temporal EV secretion profile and cell viability of neurons under hypoxia. Hypoxia induced a rapid increase of miR-21a-5p secretion in the EVs, which preceded the elevation of hypoxia-induced tissue or cellular miR-21a-5p. Prolonged hypoxia induced cell death and the release of morphologically distinct EVs. The EVs protected miR-21a-5p from enzymatic degradation but a remarkable fraction of miR-21a-5p remained fragile and non-EV associated. The increase in miR-21a-5p secretion may have biomarker potential, as high blood levels of miR-21-5p in stroke patients were associated with significant disability at hospital discharge. Our data provides an understanding of the dynamic regulation of EV secretion from neurons under hypoxia and provides a candidate for the prediction of recovery from ischemic stroke.This work was supported by the University of Eastern Finland, Emil Aaltonen Foundation, Paavo Nurmi Foundation, Saastamoinen Foundation, Instrumentarium Science Foundation and Business Finland (Grant number 4399/31/2019). Work with clinical samples was supported by the European Regional Development Fund - Project INBIO (No. CZ.02.1.01/0.0/0.0/16_026/0008451). Work with EVQuant was supported by the IMMPROVE Alpe d'HuZes grant of the Dutch Cancer Society (EMCR2015-8022) and the Daniel den Hoed Foundation grant for Erasmus MC Cancer Treatment Screening Facility. L.R. is supported by a predoctoral fellowship grant (IFI17/00012) and J.M. is the principal investigator of the grant PI18/804 ‘MULTI-BIO-TARGETS: a new strategy for stroke management combining outcome biomarkers and neuroprotection’, both from the Instituto de Salud Carlos III.Peer reviewe

Comunicación corta. Toxicidad del benzoato de emamectina sobre adultos de Nesidiocoris tenuis Reuter, Macrolophus pygmaeus (Rambur) (Heteroptera: Miridae) y Diglyphus isaea Walker (Hymenoptera: Eulophidae) en plantas de tomate. Estudios de semi-campo

Whiteflies, the tomato borer and leafminers are among the major pests of greenhouse tomatoes in Spain. Macrolophuspygmaeus (Heteroptera, Miridae) and Nesidiocoris tenuis are polyphagous predators of whiteflies, the tomato borer and other pests. Diglyphus isaea (Hymenoptera, Eulophidae) is an ectoparasite of leafminers. These three natural enemies are commonly released in the commercial horticultural  greenhouses of south-eastern Spain. Emamectin benzoate is a new semi-synthetic derivative of the avermectin B1 developed for Lepidoptera pest control in vegetable crops, with requested inclusion in annex I of the EU directive 91/414/EEC. As for any new insecticide that is being introduced for its use in protected tomato, it is critical to understand the level of compatibility of emamectin in frontof those major biological control agents. Potted tomato plants kept in a greenhouse were sprayed with the highestrecommended field rate of emamectin benzoate (14.25 mg L–1), and the toxicity of fresh and 7-day-old residues toadults of the three biological control agents were studied to ascertain their compatibility. The results demonstrated thecompatibility of both fresh and 7-day-old residues with the three species of natural enemies.La mosca blanca, la polilla y el minador de la hoja del tomate son algunas de las plagas más importantes de los  invernaderos españoles. Macrolophus pygmaeus (Heteroptera: Miridae) y Nesidiocoris tenuis son depredadores polífagos de la mosca blanca, la polilla y otras plagas del tomate. Diglyphus isaea (Hymenoptera: Eulophidae) es un ectoparasitoide del minador de la hoja. Estos tres enemigos naturales se usan comúnmente en sueltas inoculativas eninvernaderos comerciales del sureste español. Benzoato de emamectina es un derivado semi-sintético de la avermectinaB1, desarrollado para el control de plagas de lepidópteros en cultivos hortícolas que está siendo revisado para su inclusión en el Anejo I siguiendo la directiva EU 91/414/EEC. Al igual que para todos los insecticidas de nueva introducción en el cultivo del tomate protegido, es fundamental el conocimiento del nivel de compatibilidad del benzoato de emamectina frente a los agentes de control biológico más utilizados en este ámbito. Se aplicó el insecticida benzoato de emamectina a la dosis máxima recomendada (14,25 mg L–1) sobre plantas de tomate en invernadero para evaluar la toxicidad del residuo fresco y de siete días del insecticida sobre adultos de estos tres agentes de control biológico. Los resultados demuestran que tanto el residuo fresco como el de siete días son compatibles con las tres especies estudiadas