Anopheles mosquitoes transmit malaria, which affects one-fifth of the world population. A comprehensive understanding of mosquito behaviour is essential for the development of novel tools for vector ...control and surveillance. Despite abundant research on mosquito behaviour, little is known on the stimuli that drive malaria vectors during the landing phase of host-seeking. Using behavioural assays with a multimodal step approach we quantified both the individual and the combined effect of three host-associated stimuli in eliciting landing in Anopheles coluzzii females. We demonstrated that visual, olfactory and thermal sensory stimuli interact synergistically to increase the landing response. Furthermore, if considering only the final outcome (i.e. landing response), our insect model can bypass the absence of either a thermal or a visual stimulus, provided that at least one of these is presented simultaneously with the olfactory stimuli, suggesting that landing is the result of a flexible but accurate stimuli integration. These results have important implications for the development of mosquito control and surveillance tools.
Mosquito behavioral assays are an important component in vector research and control tool development. Here, we present a protocol for rearing Anopheles mosquitoes, performing host-seeking behavioral ...bioassays, and collecting 3D flight tracks in a large wind tunnel. We describe steps for setting up host-seeking landing assays, both as a non-choice and as a dual-choice assay, and analyzing flight tracks. This protocol can be applied in the research of several behavioral traits, including nectar seeking, resting, mating, and oviposition behavior.
For complete details on the use and execution of this protocol, please refer to Carnaghi et al.1
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•Protocol for rearing Anopheles mosquitoes to be used in behavioral assays•Protocol for behavioral assays in a wind tunnel coupled with a 3D tracking system•Detailed workflow instructions for Anopheles host-seeking behavioral studies•Adaptable for other behavioral traits and other mosquito species
Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.
Mosquito behavioral assays are an important component in vector research and control tool development. Here, we present a protocol for rearing Anopheles mosquitoes, performing host-seeking behavioral bioassays, and collecting 3D flight tracks in a large wind tunnel. We describe steps for setting up host-seeking landing assays, both as a non-choice and as a dual-choice assay, and analyzing flight tracks. This protocol can be applied in the research of several behavioral traits, including nectar seeking, resting, mating, and oviposition behavior.
Malaria prevention relies on mosquito control interventions that use insecticides and exploit mosquito behavior. The rise of insecticide resistance and changing transmission dynamics urgently demand ...vector control innovation. To identify behavioral traits that could be incorporated into such tools, we investigated the flight and landing response of Anopheles coluzzii to human-like host cues. We show that landing rate is directly proportional to the surface area of thermal stimulus, whereas close-range orientation is modulated by both thermal and visual inputs. We modeled anopheline eye optics to theorize the distance at which visual targets can be detected under a range of conditions, and experimentally established mosquito preference for landing on larger targets, although landing density is greater on small targets. Target orientation does not affect landing rate; however, vertical targets can be resolved at greater distance than horizontal targets of the same size. Mosquito traps for vector control could be significantly enhanced by incorporating these features.
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•Development of an insect eye model that estimates resolvable distances of targets•Area of thermal cue influences landing in Anopheles mosquitoes•Size, but not spatial orientation, influences target attractiveness and efficiency•Visual and thermal cues drive close-range attraction; thermal cues drive landing
Disease; Biological sciences; Entomology; Evolutionary biology
Blackfly members of the Simulium damnosum complex are major vectors of the parasite that causes onchocerciasis in Africa and Yemen, with other vector species involved in a few localized areas of ...Africa and in the Neotropics. Although the life cycle of these blackflies is linked to fast-flowing rivers, they can travel long distances (up to at least 500 km), calling into question how transmission zones are defined. Knowledge of the short- and long-range dispersal of these vectors could inform where control interventions and monitoring are necessary if targets for onchocerciasis elimination are to be met. Yet, research on blackfly dispersal has been limited and fragmented over the last 70 years. Here, we review the literature on the dispersal of onchocerciasis vectors, and we show the need for further research to establish how far larvae can travel downstream; the extent to which adults invade transmission zones; and whether adults migrate in a series of successive short movements or in single long-distance shifts, or use both methods.
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•T. elata larval survival outcomes depend on prey slug species.•Successful pupariation in T. elata is reduced for larvae fed on nematode-exposed slugs.•90% of T. elata neonate larvae ...without prey for four days pupariate successfully.•Neonate and third instar larvae appear to prioritise different predatory strategies.
While the larval stage of Tetanocera elata (Diptera: Sciomyzidae) is a known parasitoid and predator of pestiferous slugs, its biology and predatory behavior as well as its interaction with slug parasitic nematodes requires further investigation. In this study, survival of larvae fed from the neonate stage on Deroceras reticulatum Müller (a previously known prey species) was significantly greater (P = 0.023) than for larvae fed on Deroceras invadens Reise with 100% and 40% survival respectively. However, when fed solely on D. reticulatum which were previously exposed to P. hermaphrodita, only 20% of neonate larvae pupariated successfully. Ninety percent of neonate larvae maintained without food for the first four days and subsequently fed on D. reticulatum pupariated successfully although this decreased to below 50% for ≥6 days without food. Predatory third instar T. elata larvae appeared to select nematode-exposed D. reticulatum over non-exposed slugs with the continued feeding on nematode-exposed slugs also reducing the chances of successful pupariation by 25%. Records of maximum egg-laying by laboratory-reared female adults were greater (487 eggs) than previously recorded for field-caught adults (3 7 3). The implications of these results for the potential use of T. elata as a biological control agent of pestiferous slugs are discussed.
The impact of selected entomopathogenic nematodes and Phasmarhabditis hermaphrodita on the European-Union-protected slug Geomalacus maculosus and the sympatric Lehmannia marginata was investigated. ...There was no significant difference in mortality between slugs treated with nematodes and their controls. The presence of P. hermaphrodita in two G. maculosus cadavers may be the result of necromenic behaviour. This study constitutes the first record of P. californica in Europe.
Entomology is key to understanding terrestrial and freshwater ecosystems at a time of unprecedented anthropogenic environmental change and offers substantial untapped potential to benefit humanity in ...a variety of ways, from improving agricultural practices to managing vector‐borne diseases and inspiring technological advances.
We identified high priority challenges for entomology using an inclusive, open, and democratic four‐stage prioritisation approach, conducted among the membership and affiliates (hereafter ‘members’) of the UK‐based Royal Entomological Society (RES).
A list of 710 challenges was gathered from 189 RES members. Thematic analysis was used to group suggestions, followed by an online vote to determine initial priorities, which were subsequently ranked during an online workshop involving 37 participants.
The outcome was a set of 61 priority challenges within four groupings of related themes: (i) ‘Fundamental Research’ (themes: Taxonomy, ‘Blue Skies’ defined as research ideas without immediate practical application, Methods and Techniques); (ii) ‘Anthropogenic Impacts and Conservation’ (themes: Anthropogenic Impacts, Conservation Options); (iii) ‘Uses, Ecosystem Services and Disservices’ (themes: Ecosystem Benefits, Technology and Resources use of insects as a resource, or as inspiration, Pests); (iv) ‘Collaboration, Engagement and Training’ (themes: Knowledge Access, Training and Collaboration, Societal Engagement).
Priority challenges encompass research questions, funding objectives, new technologies, and priorities for outreach and engagement. Examples include training taxonomists, establishing a global network of insect monitoring sites, understanding the extent of insect declines, exploring roles of cultivated insects in food supply chains, and connecting professional with amateur entomologists. Responses to different challenges could be led by amateur and professional entomologists, at all career stages.
Overall, the challenges provide a diverse array of options to inspire and initiate entomological activities and reveal the potential of entomology to contribute to addressing global challenges related to human health and well‐being, and environmental change.
We present a set of grand challenges for entomology in the 21st Century, identified by members of the UK's Royal Entomological Society (RES), using a participatory prioritisation approach.
The 61 priority challenges, falling into 11 themes, provide a diverse array of options to inspire and initiate entomological activities, including research, funding, technology development, and outreach and engagement.
Together, they represent a bright future for a science of entomology that deliver benefits to humanity and safeguards insect biodiversity.
Purpose
Everolimus has been shown to be effective for advanced pancreatic neuroendocrine tumours (pNETs), but its positioning in the therapeutic algorithm for pNETs is matter of debate.
Methods
With ...the aim to shed light on this point, we performed an up-to-date critical review taking into account the results of both retrospective and prospective published studies, and the recommendations of international guidelines. In addition, we performed an extensive search on the Clinical Trial Registries databases worldwide, to gather information on the ongoing clinical trials related to this specific topic.
Results
We identified eight retrospective published studies, two prospective published studies, and five registered clinical trials. Moreover, we analyzed the content of four widespread international guidelines.
Conclusions
Our critical review confirms the lack of high-quality data to recommend everolimus as the first line therapy for pNETs. The ongoing clinical trials reported in this review will hopefully help clinicians, in the near future, to better evaluate the role of everolimus as the first line therapy for pNETs. However, at the moment, there is already enough evidence to recommend everolimus as the first line therapy for patients with symptomatic malignant unresectable insulin-secreting pNETs, to control the endocrine syndrome regardless of tumour growth.
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