Conférences plénières

Abstract: Aedes aegypti is the primary vector of the most important arboviruses causing human diseases: dengue, chikungunya, Zika and urban yellow fever. The species originated in the islands of the Southwest Indian Ocean, before colonizing Africa <85,000 years ago and spreading to the global tropics and subtropics in the last half century. Its expansion to temperate latitudes continues today aided by human-mediated transport of adults, larvae, or eggs and climate change. Range expansion, combined with Ae. aegypti adaptability to thrive in human environments, dramatically increases the percentage of global population at risk for diseases it transmits. I will talk about the current distribution of Ae. aegypti, recent invasions, discuss the use of population genomics to investigate the evolutionary history of the species and how human activity has shaped the distribution of these species throughout the years, and how this information can contribute to vector control.

Abstract: The world is a stressful place. Stressors act on biotic systems at the molecular and biochemical levels. In multicellular animals, like insects, these subcellular impacts manifest problems that cascade through cellular, tissue, organ, and organ systems to ultimately challenge fitness. How and why insects experience or avoid these effects is important for forecasting change in the natural world, for predicting and controlling their negative impacts on human endeavours, and for leveraging their enormous positive potential. In this talk, I will outline our integrative approach to understanding how conceptually simple challenges (e.g. it is too cold, or there is not enough protein) impact multiple levels of biological organization, and how insects have evolved to tolerate or circumvent such woes. We will start with how low temperatures disrupt ion and water balance in cold-intolerant species, driving a systemic loss of homeostasis, injury, and death. We will then touch on how some very cold tolerant species of interest, like the mountain pine beetle, or Asian tiger mosquito have evolved to physiologically avoid these pesky issues in cold winters and survive the cold. Lastly, we will explore how we can use integrative stress physiology as one way to improve insect mass rearing, with a focus on how we can make cricket rearing for food and feed more productive and sustainable.

Abstract: Having hitchhiked with human travellers for millenia, invasive mosquito species were transported intercontinentally on sailing vessels during the 15-19^th centuries and on container ships beginning with the 20^th century. Outbreaks of mosquito-borne diseases, including yellow fever, malaria (human and avian), filariasis, dengue, chikungunya, West Nile fever, and Zika have been attributed to and amplified by invasive vector species. Drought-resistant eggs and domesticity both favor invasiveness in mosquitoes, and pre-adaptations in their native ranges, such as preferences for disturbed, ecotonal habitats, may have facilitated the invasive successes of Aedes aegypti (L.) and Aedes albopictus Skuse. Independent invasions by Ae. albopictus in 1985 led to competitive exclusions of Ae. aegypti in southeastern USA but not in Brazil. Experiments identified asymmetric reproductive interference (=satyrization) as causing the rapid displacements of Ae. aegypti in the USA but not in Brazil, where male Ae. albopictus are ineffective satyrs. In 2012 the Indian vector Anopheles stephensi Liston was recognized as the major transmitter during a malaria outbreak in arid Djibouti. Now widespread in Africa, invasive An. stephensi occupies a more urbanized niche than native vector species and, hence, represents a new obstacle to malaria control on that continent. In southern Florida, the Burmese python has decreased mammalian diversity in areas of the Everglades where this invasive reptile is common. Everglades virus, which circulates through murid rodent hosts, is now 10X more prevalent in Culex cedecei Stone and Hair in areas where this snake is common because mosquito vectors have few alternative mammals to feed upon.

Abstract: Entomologists can find themselves in a contentious environment when biological, political and social factors conflict. One example is the complex challenge of Lyme disease diagnosis and treatment. The current paradigm of Lyme disease covers multiple different Borrelia pathogen strains, tick vector species, vertebrate host species, co-infections and limits to detection. Diverging perspectives are provided by ecology, molecular biology, public health and politics, with debate particularly revolving around chronic Lyme infection. Improved technologies such as high-throughput sequencing have bridged knowledge gaps but there is less understanding of the limitations of these technologies. However, determination to push boundaries drives progress, and the Canadian Lyme Disease Foundation (CanLyme) remains committed to such progress by supporting increased understanding of tick biology, including the role of tick endosymbionts, tracking tick population spread, exposure to novel hosts, and constraints on transmission. The history of insecticide resistance provides perspective for a parallel discussion on the overuse and misuse of antibiotics. The history of Lyme patient advocacy is also instructive, particularly in distinguishing evidence from assumptions, and understanding the human costs of delaying investigation into co-infections and novel treatments. As we work toward improved public dialogue on adaptable evidence-based treatment protocols, entomologists have remained integral to translating science into action.