This is the ninth of ten short news articles written by students, during the professional development class of Fall 2022, about each other's research.
Student Research Spotlight - Casey Cruse
By Michael Hill
Our crops are in danger! There is a nasty culprit that quickly decimates many important crops, such as potatoes, tomatoes, and eggplants. Although tiny by itself, it can come in droves and defoliate an entire plant in a single night. This bandit is the Colorado potato beetle. Hailing from western North America, it has invaded Europe and other parts of the US. People have been fighting this pest for decades. Conventional pesticides are proving ineffective, as these persistent insects can quickly develop resistance to the toxins. To combat this, MSc student Casey Cruse will investigate novel control strategies by targeting the beetles’ olfactory systems, which is their sense of smell.
Cruse says, "as insecticide resistance becomes more of a problem with this pest species, it is necessary to develop alternative ways to manage them. Understanding the potato beetle’s olfaction, specifically what proteins and enzymes in their olfactory system help them to find mates and host plants, can aid this development."
Much like our noses, beetles use their antennae to detect their environment. A healthy and hungry Colorado potato beetle can smell fresh potato leaves using their antennae and will be attracted to these leaves. Cruse predicts that the suppression of enzymes highly expressed in the antennae will reduce this attraction to their host plant. She will test this by inhibiting the genes that produce these enzymes and observing beetles’ responses to the scent of potato leaves. These responses will be compared to those of beetles whose genes have not been suppressed.
Cruse hopes that her experiment will unlock the mysteries surrounding beetle olfaction. This discovery of information could lead to new Integrated Pest Management (IPM) strategies, such as utilizing chemicals that target the genes that are critical to the Colorado potato beetle’s sense of smell. Specialized pesticides are beneficial because they are less likely to affect non-target organisms.
In addition to the Colorado potato beetle, Cruse’s research can potentially help scientists identify the root processes of olfaction in all beetles. As beetles are one of the most diverse groups of animals on the planet, they play many diverse roles in different ecosystems. Some beetles species are important pollinators, for example. Therefore, if researchers can comprehend how beetle olfaction works, they may be able to devise ways to help the populations of beneficial beetles thrive.
By further growing the knowledge of the genetic and molecular factors that play a role in beetle olfaction, there may be new ways to develop solutions to help prevent pest beetles from targeting crop plants by interrupting their sensory systems. With newfound knowledge, there may be hopes to finally put this outlaw behind bars.
Casey Cruse’s thesis advisors are Drs. Fang Zhu and Tom Baker, and she collaborates with Dr. Michael Wolfin, Dr. Etya Amsalem, Dr. Timothy Moural, and Sonu Koirala B K. The Alex and Jesse Black Graduate Fellowship from Penn State supports this research project.
