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A critical component of integrated pest management is minimizing disruption of biological control by reducing the use of pesticides with significant non-target effects on natural enemies. Insecticide non-target effects testing for natural enemies has become increasingly common, but research examining the non-target effects of herbicides on natural enemies is scarce, and recommendations regarding herbicide selectivity are non-existent. We used meta-analysis to summarize laboratory bioassays testing non-target effects of herbicides on arthropod natural enemies and identify patterns in taxon susceptibility and active ingredient toxicity. Data were extracted from 78 papers representing 801 total observations. Herbicides increased natural enemy mortality and decreased longevity, reproduction, and predation. Mesostigmatan mites and hemipterans were the most sensitive to herbicides, and spiders, neuropterans, and hymenopterans were the least sensitive. Mortality was higher in juvenile predators versus parasitoids but did not differ between adults; parasitoid juveniles are likely better protected within the host. In terms of acute mortality, metribuzin, glufosinate, and oxyfluorfen were the most harmful herbicides. Only nicosulfuron, rimsulfuron, pendimethalin, phenmedipham, atrazine, and urea did not increase natural enemy mortality. The large effect size of glufosinate is particularly concerning, as it is the most likely replacement herbicide for glyphosate in many crops. Many active ingredients remain under-studied. Our analysis indicates that herbicides have a strong potential to disrupt biological control in cropping systems.
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Preserving ecosystem services, such as natural enemies that can provide pest control, can positively impact crops without compromising agricultural yield. Even though controlling pests by natural enemies has been suggested to reduce pests in agriculture, growers continue using conventional pesticides that kill beneficial predators. Here we studied whether the predation of avian and insect-beneficial predators varies in an apple orchard with conventional insecticide use compared to a bordering tree stand without insecticides. We studied the predation rates of mealworm pupae as a proxy to coddling moth pupae at 42 stations in both an apple orchard and a Eucalyptus stand at three distances (0 m, 50 m, and 100 m) from the border. Half of the stations were netted to prevent bird predation but were accessible to insects. The other half were non-netted and accessible to birds. We conducted six trials, each lasting two weeks, during which we recorded the predation of 504 stations with 5040 pupae. To validate which species predated the pupae, we added video cameras that took RGB videos during the day and IR videos at night in 45 stations and found that in net-free stations, birds preyed in 94.1% of stations in the orchard and 81.8% in the Eucalyptus stand. However, ants predated 70% of the pupae in stations with nets in the orchards and 100% in stations in the Eucalyptus strands. In addition, we found a significant rise in predation by birds as the distance into the orchard increased. Conversely, insect predation declined within the orchard but escalated in the adjacent unmanaged area. These findings suggest that the orchard's environment negatively affects beneficial insect activity, specifically predatory ants. This study demonstrates that birds can play an essential role in predating insect pests inside the orchard. In addition, we believe that the decreased predation of ants within the orchard was due to intense insecticide use.
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Recent advancements in next-generation sequencing (NGS) technology and bioinformatics tools have revealed a vast array of viral diversity in insects, particularly RNA viruses. However, our current understanding of insect RNA viruses has primarily focused on hematophagous insects due to their medical importance, while research on the viromes of agriculturally relevant insects remains limited. This comprehensive review aims to address the gap by providing an overview of the diversity of RNA viruses in agricultural pests and beneficial insects within the agricultural ecosystem. Based on the NCBI Virus Database, over eight hundred RNA viruses belonging to 39 viral families have been reported in more than three hundred agricultural insect species. These viruses are predominantly found in the insect orders of Hymenoptera, Hemiptera, Thysanoptera, Lepidoptera, Diptera, Coleoptera, and Orthoptera. These findings have significantly enriched our understanding of RNA viral diversity in agricultural insects. While further virome investigations are necessary to expand our knowledge to more insect species, it is crucial to explore the biological roles of these identified RNA viruses within insects in future studies. This review also highlights the limitations and challenges for the effective virus discovery through NGS and their potential solutions, which might facilitate for the development of innovative bioinformatic tools in the future.
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Pollinators are declining globally, potentially reducing both human food supply and plant diversity. To support pollinator populations, planting of nectar-rich plants with different flowering seasons is encouraged while promoting wind-pollinated plants, including grasses, is rarely recommended. However, many bees and other pollinators collect pollen from grasses which is used as a protein source. In addition to pollen, Hymenoptera may also collect honeydew from plants infested with aphids. In this study, insects consuming or collecting pollen from sweet sorghum, Sorghum bicolor, were recorded while pan traps and yellow sticky card surveys were placed in grain sorghum fields and in areas with Johnsongrass, Sorghum halepense to assess the Hymenoptera response to honeydew excreted by the sorghum aphid (SA), Melanaphis sorghi. Five genera of insects, including bees, hoverflies, and earwigs, were observed feeding on pollen in sweet sorghum, with differences observed by date, but not plant height or panicle length. Nearly 2000 Hymenoptera belonging to 29 families were collected from grain sorghum with 84% associated with aphid infestations. About 4 times as many Hymenoptera were collected in SA infested sorghum with significantly more ants, halictid bees, scelionid, sphecid, encyrtid, mymarid, diapriid and braconid wasps were found in infested sorghum plots. In Johnsongrass plots, 20 times more Hymenoptera were collected from infested plots. Together, the data suggest that sorghum is serving as a pollen food source for hoverflies, earwigs, and bees and sorghum susceptible to SA could provide energy from honeydew. Future research should examine whether planting strips of susceptible sorghum at crop field edges would benefit Hymenoptera and pollinators.
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While the information on live insect shipments provided in this thematic issue of the Scientific and Technical Review could not be exhaustive, it clearly represents a broad variety of trade, of substantial value, involving many stakeholders throughout the world. The contributions to this issue demonstrate that most of the trade in insects is carried out safely and efficiently. The concerns related to shipping insects described within this issue fall broadly into four categories: risks to human, animal and environmental health; delays and loss of quality; refusal of carriage; and high and variable costs. Some opportunities for improvements to insect shipping for diverse stakeholders are shown across these four areas of concern, with specific recommendations and a general call for further collaboration among stakeholders.
À défaut d'être exhaustives, les informations fournies dans ce numéro thématique de la Revue scientifique et technique consacré aux expéditions d'insectes vivants recouvrent clairement un très large éventail de ces échanges, qui représentent une valeur importante et auxquels participent de nombreux intervenants dans le monde entier. Les contributions réunies dans ce numéro montrent que l'essentiel des échanges d'insectes se déroule sans risques associés et de manière efficiente. Les sujets de préoccupation relatifs aux expéditions d'insectes mis en avant dans ce numéro relèvent, en général, de l'une des quatre catégories suivantes : risques pour la santé humaine, animale et environnementale ; retards et perte de qualité ; refus de transport ; coüts élevés et sujets à variations. Les auteurs font état des perspectives d'amélioration des expéditions d'insectes qui s'offrent à plusieurs parties prenantes, pour chacune de ces catégories, et présentent des recommandations spécifiques ainsi qu'un appel général à renforcer la collaboration pluri-acteurs.
Aunque la información presentada en este número temático de la Revista científica y técnica sobre el transporte de insectos vivos no puede ser exhaustiva, sí da clara cuenta de diversos tipos de comercio que revisten importancia y convocan a numerosos interlocutores del mundo entero. Los artículos de este número evidencian que el comercio de insectos discurre la mayor parte del tiempo con eficacia y en condiciones seguras. Los problemas ligados al transporte de insectos que se exponen en este número corresponden, en líneas generales, a cuatro clases: riesgos para la salud humana, animal o ambiental; retrasos y pérdida de calidad; denegación de transporte; y costos elevados y variables. En relación con estos cuatro ámbitos problemáticos, aquí se apuntan algunas posibilidades para que distintas partes introduzcan mejoras en el transporte de insectos, se presentan recomendaciones específicas y se hace una exhortación general a una mayor colaboración entre los interlocutores del sector.
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Insetos , Animais , HumanosRESUMO
International trade in live insects involves the shipping of many different species, for various purposes, with a variety of handling requirements regulated by numerous authorities with varying objectives. The diversity of factors at play has both created and been subject to a complex regulatory landscape. A review of global production, shipping and use experiences from a range of perspectives has shown gaps and inconsistencies in international guidance and national implementation. Private carriers add another layer of uncertainty that is disproportionate to risks, resulting in variable practices and charges. Many benefits can come from international trade in insects, including pollinator services, control of pests and of disease vectors, and enhanced international scientific research and innovation. These benefits will be better achieved through a more evidence-based and efficient approach to regulating trade. This change in approach will in turn require an improved and widely accepted risk-management landscape for insect trade.
Le commerce international d'insectes vivants s'appuie sur les expéditions de nombreuses espèces différentes à diverses fins, assorties de multiples exigences relatives à la manutention régies par des autorités différentes poursuivant des objectifs distincts. La diversité des facteurs en jeu a rendu nécessaire la création d'un paysage normatif complexe, avec les contraintes qui lui sont associées. L'examen à l'échelle mondiale de la production, du transport et des expériences dans ce domaine depuis diverses perspectives a révélé un certain nombre de lacunes et d'incohérences au niveau des directives internationales et de leurs applications concrètes dans les pays. Les transporteurs privés ajoutent une dimension d'incertitude supplémentaire qui est disproportionnée par rapport aux risques, ce qui entraîne une forte variabilité des pratiques et des charges. Les échanges internationaux d'insectes génèrent nombre d'activités bénéfiques, parmi lesquelles les services de pollinisation, la lutte contre les ravageurs et les vecteurs de maladie, et l'accroissement de la recherche scientifique internationale et de l'innovation. Les objectifs attendus seront mieux atteints en adoptant une approche de la réglementation des échanges qui s'appuie davantage sur des éléments factuels et sur les gains d'efficacité. Ce changement méthodologique nécessitera à son tour la mise en place d'un cadre amélioré et plus largement accepté de la gestion des risques dans le domaine du commerce des insectes.
El comercio internacional de insectos vivos, que supone el transporte de muchas especies diferentes con fines diversos, se acompaña de requisitos de manipulación que dictan numerosas autoridades con todo tipo de objetivos. La diversidad de los factores que entran en juego ha sido a la vez causa y consecuencia de un complejo panorama reglamentario. Los autores, tras describir un estudio a escala mundial de la experiencia de producción, transporte y utilización de insectos vivos desde diferentes puntos de vista, exponen las carencias e incoherencias observadas en las directrices internacionales y su traslación a escala nacional. Los transportistas privados añaden otro factor de incertidumbre que tiene un peso desproporcionado en relación con el nivel de riesgo y se traduce en procedimientos y precios heterogéneos. El comercio internacional de insectos puede traer consigo muchos beneficios, en particular servicios de polinización, control de plagas y de vectores de enfermedad, y avances de la investigación e innovación científica a escala internacional. Pero obtener esos beneficios será más fácil si se aborda la regulación del comercio de manera más eficaz y científicamente fundamentada, operando un cambio de lógica que exigirá, a su vez, la aplicación al comercio de insectos de un régimen más sofisticado y ampliamente aceptado de gestión de los riesgos.
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Comércio , Internacionalidade , Animais , Insetos/fisiologiaRESUMO
Environmental impacts of conventional agriculture have generated interest in sustainable agriculture. Biological pest control is a fundamental tool, and ants are key players providing ecological services, as well as some disservices. We have used a meta-analytical approach to investigate the contribution of ants to biological control, considering their effects on pest and natural enemy abundance, plant damage and crop yield. We also evaluated whether the effects of ants are modulated by traits of ants, pests and other natural enemies, as well as by field size, crop system and experiment duration. Overall (considering all meta-analyses), from 52 studies on 17 different crops, we found that ants decrease the abundance of non-honeydew-producing pests, decrease plant damage and increase crop yield (services). In addition, ants decrease the abundance of natural enemies, mainly the generalist ones, and increase honeydew-producing pest abundance (disservices). We show that the pest control and plant protection provided by ants are boosted in shaded crops compared to monocultures. Furthermore, ants increase crop yield in shaded crops, and this effect increases with time. Finally, we bring new insights such as the importance of shaded crops to ant services, providing a good tool for farmers and stakeholders considering sustainable farming practices.
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Formigas , Agricultura , Animais , Produtos Agrícolas , Controle Biológico de VetoresRESUMO
With approximately 160,000 identified species of butterflies and moths, Lepidoptera are among the most species-rich and diverse insect orders. Lepidopteran insects have fundamental ecosystem functions as pollinators and valuable food sources for countless animals. Furthermore, Lepidoptera have a significant impact on the economy and global food security because many species in their larval stage are harmful pests of staple food crops. Moreover, domesticated species such as the silkworm Bombyx mori produce silk and silk byproducts that are utilized by the luxury textile, biomedical, and cosmetics sectors. Several Lepidoptera have been fundamental as model organisms for basic biological research, from formal genetics to evolutionary studies. Regarding chronobiology, in the 1970s, Truman's seminal transplantation experiments on different lepidopteran species were the first to show that the circadian clock resides in the brain. With the implementation of molecular genetics, subsequent studies identified key differences in core components of the molecular circadian clock of Lepidoptera compared to the dipteran Drosophila melanogaster, the dominant insect species in chronobiological research. More recently, studies on the butterfly Danaus plexippus have been fundamental in characterizing the interplay between the circadian clock and navigation during the seasonal migration of this species. Moreover, the advent of Next Generation Omic technologies has resulted in the production of many publicly available datasets regarding circadian clocks in pest and beneficial Lepidoptera. This review presents an updated overview of the molecular and anatomical organization of the circadian clock in Lepidoptera. We report different behavioral circadian rhythms currently identified, focusing on the importance of the circadian clock in controlling developmental, mating and migration phenotypes. We then describe the ecological importance of circadian clocks detailing the complex interplay between the feeding behavior of these organisms and plants. Finally, we discuss how the characterization of these features could be useful in both pest control, and in optimizing rearing of beneficial Lepidoptera.
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Resumen Se presenta una revisión de los ejemplares de Coccinellini micofagos procedentes de varias provincias del departamento del Cusco, en el sur oriente de Perú. Este grupo presenta actualmente nueve especies en el país, dentro de los géneros Oxytella Weise 1902, y Psyllobora Chevrolat 1836. En el material examinado se reporta la ocurrencia de cinco de ellas: Oxytella longula Weise, Psyllobora marshalli Crotch, abancayana Almeida, P. constantini González, Perla & Almeida, y P. hybrida (Mulsant); además de otras tres especies, aún no identificadas, dentro del género Psyllobora. Para cada especie se presenta una diagnosis, fotografías y microfotografías de habito y estructuras genitales, e información sobre su distribución en Cusco.
Abstract In this work, we presented a review of the specimens of mycophagous Coccinellini from various provinces of the Cusco Department, south east of Peru. This group currently has nine species in the country, within the genera Oxytella Weise 1902, and Psyllobora Chevrolat 1836. In the material examined the occurrence of five of them is reported: Oxytella longula Weise, Psyllobora marshalli Crotch, P. abancayana Almeida, P. constantini González, Perla & Almeida, and P. hybrida (Mulsant); in addition to three other species, not yet identified, within the genus Psyllobora. For each species a diagnosis, photographs and photomicrographs of habit and genital structures, and information on their distribution in Cusco are presented.
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The fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) has successfully invaded Africa, where it has significantly impacted maize and sorghum production. Management of FAW in Africa predominantly relies on synthetic insecticides, which are expensive, and negatively impact the environment and beneficial insects. We, therefore, conducted field surveys in Uganda in 2017 and 2019 to identify egg and larval parasitoids of FAW for possible use in integrated pest management (IPM) programs. Parasitoids were identified by their mitochondrial DNA cytochrome c oxidase subunit 1 (mtCOI) gene sequences. We identified 13 parasitoid species belonging to three families of Hymenoptera: Platygastridae, Braconidae and Ichneumonidae, as well as one Dipteran family (Tachinidae). Coccygidium spp. and Chelonus bifoveolatus were the most abundant and widely distributed parasitoids. Overall, parasitism averaged 9.2% and ranged from 3.1% to 50% in 2017, and 0.8% to 33% in 2019. Parasitism by Sturmiopsis parasitica, Diolcogaster sp., and Cotesia flavipes on FAW in maize crops are reported for the first time. Our results suggest high biological diversity of FAW parasitoids, which should be exploited in the IPM of the FAW in Uganda.
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Imidacloprid is an insecticide that is used globally and is suspected to be at least partly responsible for the decrease in the number of pollinator insects. The effects of an LC20 of imidacloprid on the parasitic behavior of the parasitoid wasp Leptopilina boulardi were investigated. Two genetically identical L. boulardi strains were used for the experiments. The strains differed in that one was infected by LbFvirus and the other was not. LbFvirus is a virus that induces an increase in the superparasitism behavior of the wasp. Results of two previous works have shown that the organophosphorus insecticide chlorpyrifos induces an increase in the superparasitism rate of L. boulardi through its specific action on cholinergic nervous pathways. Imidacloprid targets receptors implicated in cholinergic nervous pathways and thus it was expected that imidacloprid would also increase the superparasitism rate of L. boulardi. However, the results of the present experiment demonstrate that imidacloprid does not interfere with the parasitic behavior of L. boulardi and does not increase the rate of superparasitization. It can then be concluded that the major target of imidacloprid, namely type 1 α-bungarotoxin resistant nicotinic acetylcholine receptors (nAChR1), which imidacloprid is an agonist of, and the minor target, type D α-bungarotoxin sensitive nicotinic acetylcholine receptors (nAChRD), which imidacloprid is an antagonist of, are not involved in the superparasitism behavior by L. boulardi. Therefore, the superparasitism behavior of the parasitoid wasp is controlled by cholinergic pathways that do not involve nAChR1 or nAChRD subtype receptors. These findings may enable a better understanding of the mechanisms by which the LbFvirus acts, and contribute to a better evaluation of the potential environmental impact of imidacloprid use.
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Comportamento Animal/efeitos dos fármacos , Interações Hospedeiro-Parasita/efeitos dos fármacos , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Receptores Nicotínicos/metabolismo , Vespas/efeitos dos fármacos , Animais , Drosophila/parasitologia , Vespas/metabolismo , Vespas/virologiaRESUMO
The widespread use of neonicotinoid insecticides is controversial due to their persistence in the environment and concern for the long-term consequences of their use. We present a simple, low-cost method for the sensitive and efficient extraction from soil of thiamethoxam, clothianidin and imidacloprid, the three neonicotinoid insecticides approved in New Zealand as seed coatings. We have validated this method by applying it to uncontaminated soil samples spiked with environmentally relevant concentrations of the three targets. Absolute recoveries were >80% with instrument detection limits <1â¯ngâ¯g-1 wet soil. We also applied the method to soil samples collected from maize fields in New Zealand's North Island and found imidacloprid in 43 out of 45 samples and clothianidin in every one. Mean imidacloprid concentrations varied from 0.5 to 9.4â¯ngâ¯g-1 (wet weight) and clothianidin from 2.1 to 26.7â¯ngâ¯g-1 (wet weight). Imidacloprid concentrations exceed the New Zealand Environmental Protection Agency's Environmental Exposure Limit of 1â¯ngâ¯g-1 (dry weight) at eight of the nine sites sampled. These results are remarkable because we have detected multiple neonicotinoid residues at every site sampled. Imidacloprid residues appear to persist at significant concentrations at five of our sites from an application at least two years previously. This is only the third study to report the presence of neonicotinoid residues in NZ's environment and the first to show that those residues are persistent in the environment at nominally hazardous concentrations.
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Monitoramento Ambiental/métodos , Inseticidas/análise , Neonicotinoides/análise , Resíduos de Praguicidas/análise , Poluentes do Solo/análise , Zea mays/crescimento & desenvolvimento , Animais , Nova Zelândia , Sementes/crescimento & desenvolvimento , Solo/químicaRESUMO
Biological invasions, the expansion of agricultural frontiers, and climate change favor encounters of divergent lineages of animals and plants, increasing the likelihood of hybridization. However, hybridization of insect species and its consequences for agroecosystems have not received sufficient attention. Gene exchange between distinct and distant genetic pools can improve the survival and reproduction of insect pests, and threaten beneficial insects in disturbed agricultural environments. Hybridization may be the underlying explanation for the recurrent pest outbreaks and control failures in putative hybrid zones, as suspected for bollworm, corn borer, whiteflies, and stink bugs. Reliable predictions of the types of changes that can be expected in pest insect genomes and fitness, and of their impacts on the fate of species and populations remain elusive. Typical steps in pest management, such as insect identification, pest monitoring, and control are likely affected by gene flow and adaptive introgression mediated by hybridization, and we do not have ways to respond to or mitigate the problem. To address the adverse effects of farming intensification and global trade, we must ensure that current integrated pest management programs incorporate up-to-date monitoring and diagnostic tools. The rapid identification of hybrids, quantification of levels of introgression, and in-depth knowledge of what genes have been transferred may help to explain and predict insect population outbreaks and control failures in the future. © 2019 Society of Chemical Industry.
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Hibridização Genética , Controle de Insetos , Insetos/fisiologia , Agricultura , Animais , Insetos/genética , Dinâmica PopulacionalRESUMO
Controlling weeds is critical for improving the yield and quality of crops. Herbicides are the most commonly applied pesticides in agro-ecosystems. Herbicides affect insects directly as contact damage and indirectly by influencing food supplies. The innate susceptibility, life stages, and mode of feeding of insects can affect the herbicide-insect interaction. Interaction of herbicides with insect pest and beneficial insects is mainly indirect and absence of weeds either can reduce the insect population or causes switching of host plant and hence can also increase the population. The direct effect of herbicides depends on carrier or surfactant used. Presence of herbicides also provides surfactant to insecticides and increases impact of insecticides. At present, most reports on impact of herbicides indicate alterations in insect survival or egg production due to increase or decrease in host plant population as an indirect affect, only a handful studies reported a direct topical effect of these herbicides on egg, larvae/nymphs and adults of various insects. Further exploration of this interaction seems intriguing. Use of bio-herbicides, cultural control methods, and judicious use of herbicides could offer ecologically sustainable approaches to reduce impact of herbicides on insects.
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Monitoramento Ambiental , Cadeia Alimentar , Herbicidas/análise , Insetos/fisiologia , Animais , Produtos Agrícolas , PraguicidasRESUMO
Neonicotinoid insecticides are currently the fastest-growing and most widely used insecticide class worldwide. Valued for their versatility in application, these insecticides may cause deleterious effects in a range of non-target (beneficial) arthropods. However, it remains unclear whether strong patterns exist in terms of their major effects, if broad measures of arthropod performance are negatively affected, or whether different functional groups are equally vulnerable. Here, we present a meta-analysis of 372 observations from 44 field and laboratory studies that describe neonicotinoid effects on 14 arthropod orders across five broad performance measures: abundance, behavior, condition, reproductive success, and survival. Across studies, neonicotinoids negatively affected all performance metrics evaluated; however, magnitude of the effects varied. Arthropod behavior and survival were the most negatively affected and abundance was the least negatively affected. Effects on arthropod functional groups were inconsistent. Pollinator condition, reproductive success, and survival were significantly lower in neonicotinoid treatments compared to untreated controls; whereas, neonicotinoid effects on detritivores were not significant. Although magnitude of arthropod response to neonicotinoids varied among performance measures and functional groups, we documented a consistent negative relationship between exposure to neonicotinoid insecticides in published studies and beneficial arthropod performance.
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Artrópodes/efeitos dos fármacos , Inseticidas/efeitos adversos , Neonicotinoides/efeitos adversos , Animais , Artrópodes/fisiologia , PolinizaçãoRESUMO
Historic and current land-use changes have altered the landscape for grassland biota, with over 90% of grasslands and savannas converted to agriculture or some other use in north temperate regions. Reintegrating grasslands into agricultural landscapes can increase biodiversity while also providing valuable ecosystem services. In contrast to their well-known importance in tropical and subtropical ecosystems, the role of ants in temperate grasslands is often underappreciated. As consumers and ecosystem engineers, ants in temperate grasslands influence invertebrate, plant, and soil microbial diversity and potentially alter grassland productivity. As common and numerically dominant invertebrates in grasslands, ants can also serve as important indicator species to monitor conservation and management practices. Drawing on examples largely from mesic, north temperate studies, and from other temperate regions where necessary, we review the roles of ants as consumers and ecosystem engineers in grasslands. We also identify five avenues for future research to improve our understanding of the roles of ants in grasslands. This includes identifying how grassland fragmentation may influence ant community assembly, quantifying how ant communities impact ecosystem functions and soil processes, and understanding how ant communities and their associated interactions are impacted by climate change. In synthesizing the role of ants in temperate grasslands and identifying knowledge gaps, we hope this and future work will help inform how land managers maximize grassland conservation value while increasing multiple ecosystem services and minimizing disservices.
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Formigas , Animais , Biodiversidade , Ecossistema , Pradaria , SoloRESUMO
Dengue is the most rapidly spreading mosquito-borne viral disease in the world. The mosquito, Aedes aegypti, also spreads Yellow fever, Chikungunya, and Zika virus. As the primary vector for dengue, Ae. aegypti now occurs in over 20 countries and is a serious concern with reports of increasing insecticide resistance. Developing new treatments to manage mosquitoes are needed. Formulation of crude volatile oil from Piper betle leaves (Pb-CVO) was evaluated as a potential treatment which showed larvicidal, ovipositional, and repellency effects. Gut-histology and enzyme profiles were analyzed post treatment under in-vitro conditions. The Pb-CVO from leaves of field collected plants was obtained by steam distillation and separated through rotary evaporation. The Pb-CVO were evaluated for chemical constituents through GC-MS analyses revealed 20 vital compounds. The peak area was establish to be superior in Eudesm-7(11)-en-4-ol (14.95%). Pb-CVO were determined and tested as four different concentrations (0.25, 0.5, 1.0, and 1.5 mg/L) of Pb-CVO towards Ae. aegypti. The larvicidal effects exhibited dose dependent mortality being greatest at 1.5 mg Pb-CVO/10 g leaves. The LC50 occurred at 0.63 mg Pb-CVO/L. Larva of Ae. aegypti exposed to Pb-CVO showed significantly reduced digestive enzyme actions of α- and ß-carboxylesterases. In contrast, GST and CYP450 enzyme levels increased significantly as concentration increased. Correspondingly, oviposition deterrence index and egg hatch of Ae. aegypti exposed to sub-lethal doses of Pb-CVO demonstrated a strong effect suitable for population suppression. Repellency at 0.6 mg Pb-CVO applied as oil had a protection time of 15-210 min. Mid-gut histological of Ae. aegypti larvae showed severe damage when treated with 0.6 mg of Pb-CVO treatment compared to the control. Non-toxic effects against aquatic beneficial insects, such as Anisops bouvieri and Toxorhynchites splendens, were observed at the highest concentrations, exposed for 3 h. These results suggest that the Pb-CVO may contain effective constituents suitable for development of new vector control agents against Ae. aegypti.
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Aedes/efeitos dos fármacos , Dengue/prevenção & controle , Repelentes de Insetos/farmacologia , Insetos/efeitos dos fármacos , Inseticidas/análise , Oviposição/efeitos dos fármacos , Animais , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Resistência a Inseticidas , Larva/efeitos dos fármacos , Controle de Mosquitos , Mosquitos Vetores , Piper , Folhas de PlantaRESUMO
Native plant and beneficial insect associations are relatively unstudied yet are important in native habitat restoration programs for improving and sustaining conservation biological control of arthropod pests in agricultural crops. Milkweeds (Asclepias spp.) are currently the focus of restoration programs in the USA aimed at reversing a decline in populations of the milkweed-dependent monarch butterfly (Danaus plexippus); however, little is known of the benefits of these plants to other beneficial insects. Beneficial insects (predators, parasitoids, pollinators) attracted to two milkweed species (Asclepias speciosa, Asclepias fascicularis) in central Washington State, WA, USA were identified and counted on transparent sticky traps attached to blooms over five seasons. Combining all categories of beneficial insects, means of 128 and 126 insects per trap were recorded for A. speciosa and A. fascicularis, respectively. Predatory and parasitic flies dominated trap catches for A. speciosa while parasitic wasps were the most commonly trapped beneficial insects on A. fascicularis. Bees were trapped commonly on both species, especially A. speciosa with native bees trapped in significantly greater numbers than honey bees. Beneficial insect attraction to A. speciosa and A. fascicularis was substantial. Therefore, these plants are ideal candidates for habitat restoration, intended to enhance conservation biological control, and for pollinator conservation. In central Washington, milkweed restoration programs for enhancement of D. plexippus populations should also provide benefits for pest suppression and pollinator conservation.