Unlocking the sensory secrets of predatory wasps: towards predictive tools for managing wasps' ecosystem services in the Anthropocene

Lead Research Organisation: University College London
Department Name: Genetics Evolution and Environment

Abstract

Humans are modifying the planet at a rate never experienced before, marking a new era - the Anthropocene. Land-use change, pollutants and climate change bring a plethora of challenges for nature. It is clear that insects are profoundly affected by these challenges, with some species facing global population declines, whilst others are expanding and becoming invasive; both effects have serious consequences for humans, as we rely on insects for their ecosystem services. Insect senses - how they smell, feel and see the world - are thought to play a critical role in explaining these changes. This is because the Anthropocene is altering the chemical, visual and auditory environment for insects and disrupting the sensory mechanisms they have evolved to respond to. For example, light pollution is affecting the feeding behaviour of moths, agrochemicals are disrupting the navigational abilities of bees, air pollutants disrupt the abilities of insects to detect the sex pheromones of their mates and the floral cues released by the plants they pollinate; even temperature and humidity affects the nature of volatile chemicals used as cues by insects.

There is an urgent need to better understand how insects sense their environment. This basic science is required in order that we can develop predictive tools to forecast the impacts of the Anthropocene on insect sensory mechanisms, and to manage and protect their roles as nature-based solutions for healthy ecosystems, on which our own food, health and wellbeing depend.

Our Project addresses this urgent need using wasps as a model system. Wasps are predators of a huge diversity of insects, making them essential for controlling insect populations in natural and farmed ecosystems. This includes agricultural pests (e.g. caterpillars) and vectors of disease (e.g. flies). With over 100,000 described species and five times more thought yet to be discovered, wasps are amongst the most speciose group in the planet. Wasps are also some of the worst invasive species on the planet, causing huge ecological and economic damage. Despite their importance, we know astonishingly little about their prey, and even less about what sensory mechanisms they use to hunt prey. This matters because wasps are nature's pest-controllers; we need to have the right tools to ensure we protect their services. Experimental removal of wasps results in unmanagable populations of flies and caterpillars which decimate crops and threaten ecosystems, demonstrating the important role of wasps. We require a means to rapidly assess the ecosystem services provided by wasps - at its core, this means identifying what and how they hunt.

We use an innovative approach to fast-track the development of tools to predict the prey-type of wasps. Wasps use smells, visual and vibrational cues to detect their prey, and this should be reflected in the underlying sensory machinery - from genes to sensory organs. We will identify the sensory machinery used by wasps to hunt by looking for signs of adaptive evolution for specific sensory function in the genome and the morphology of their sensory organs (antennae, eyes, etc). We can do this due to the explosion in wasp genome sequencing, with 270 species currently available and many more in the pipeline, and with high-resolution scanning of extensive museum collections. By analysing the patterns of adaptive sensory evolution, we will provide the first comprehensive understanding of the evolutionary and mechanistic basis to sensory systems in predatory insects. We will then use these signatures to test whether we can predict prey-type based on a minimal set of sensory traits. The ultimate success would be if we can assess a wasp's ecological role from a rapid genome sequence obtained in the field.

This Project is an ambitious, high-reward, fast-track solution that promises to provide the tools to predict and protect the services provided by these critical, but overlooked facets of nature.

Publications

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