Neurocircuitry in Flies: Sight of Parasitoid Wasps Triggers Reduced Oviposition Rates
Event Type
Research Presentation
Academic Department
Biology
Location
Dana Science Building, 2nd floor
Start Date
24-4-2026 1:00 PM
End Date
24-4-2026 2:30 PM
Description
Organismal survival requires the correct recognition of environmental threats and alteration of behavioral traits. Parasitoid wasps represent a major threat to flies (Drosophila melanogaster) because they inject a single egg inside the body of fly larvae or pupae. Once hatched, the wasp larva eventually eats the fly from the inside out. Though not directly targeted, adult flies recognize this threat and respond by reducing their egg laying rates, presumably to protect their offspring. I performed co-housing experiments in which flies were housed with parasitoid wasps for 24 hours, or kept separate from any wasps, and recorded the number of eggs laid. First, I verified that the oviposition reduction response was induced by wasp exposure. Previous work suggests that flies respond only to the presence of wasps that attack fly larvae and not to those that attack fly pupae, and that wasp movement is the specific sensory cue. Therefore, I recorded and analyzed the locomotion of multiple parasitoid wasp species to characterize the visual stimuli. The larval parasitoids walk slower than pupal parasitoids, suggesting that an upper limit exists in which flies can detect wasp movement. In the fly brain, roughly one third of all neurons are devoted to processing visual stimuli. I hypothesize that there is a distinct visual pathway that is responsive to wasp movement, but its identity remains unknown. A small cluster of visual projection neurons, called lobula columnar 11 (LC11), connect the optic lobes to the central brain and are involved in wasp detection to trigger behavioral changes. To fully characterize the visual pathway, I used a whole-brain connectome dataset to identify candidate neurons positioned upstream of LC11. The GAL4/UAS system was used to target and inhibit medulla neuron (Mi1) functions. Early work, while unable to draw any significant conclusions, does suggest that silencing Mi1 neurons prevents flies from being able to respond to wasps. The long-term goal of this project is to identify the neuronal pathways throughout the fly nervous system that detect and trigger behavioral changes when exposed to dangerous situations.
Neurocircuitry in Flies: Sight of Parasitoid Wasps Triggers Reduced Oviposition Rates
Dana Science Building, 2nd floor
Organismal survival requires the correct recognition of environmental threats and alteration of behavioral traits. Parasitoid wasps represent a major threat to flies (Drosophila melanogaster) because they inject a single egg inside the body of fly larvae or pupae. Once hatched, the wasp larva eventually eats the fly from the inside out. Though not directly targeted, adult flies recognize this threat and respond by reducing their egg laying rates, presumably to protect their offspring. I performed co-housing experiments in which flies were housed with parasitoid wasps for 24 hours, or kept separate from any wasps, and recorded the number of eggs laid. First, I verified that the oviposition reduction response was induced by wasp exposure. Previous work suggests that flies respond only to the presence of wasps that attack fly larvae and not to those that attack fly pupae, and that wasp movement is the specific sensory cue. Therefore, I recorded and analyzed the locomotion of multiple parasitoid wasp species to characterize the visual stimuli. The larval parasitoids walk slower than pupal parasitoids, suggesting that an upper limit exists in which flies can detect wasp movement. In the fly brain, roughly one third of all neurons are devoted to processing visual stimuli. I hypothesize that there is a distinct visual pathway that is responsive to wasp movement, but its identity remains unknown. A small cluster of visual projection neurons, called lobula columnar 11 (LC11), connect the optic lobes to the central brain and are involved in wasp detection to trigger behavioral changes. To fully characterize the visual pathway, I used a whole-brain connectome dataset to identify candidate neurons positioned upstream of LC11. The GAL4/UAS system was used to target and inhibit medulla neuron (Mi1) functions. Early work, while unable to draw any significant conclusions, does suggest that silencing Mi1 neurons prevents flies from being able to respond to wasps. The long-term goal of this project is to identify the neuronal pathways throughout the fly nervous system that detect and trigger behavioral changes when exposed to dangerous situations.
Comments
Under the direction of Dr. Shaun Davis.