This is the first of ten short news articles written by students, during the professional development class of Fall 2022, about each other's research.
Student Research Spotlight - Charles Davis
By Sujay Paranjape
While hiking in the woods or walking through a local park, have you ever noticed weird tumor-like swellings on plants like blackberries bushes or oak trees? Those swellings are called “galls” and caused by insects and mites. The more complex and visually striking of these alien-like structures are caused by gall wasps. These wasps are ecosystem engineers, and their galls can host a diverse community of insects. Once the wasps fully develop, they chew their way through their former home and fly away to make more galls. Scientists have been studying this phenomenon for decades and there still many unknowns waiting to be explored in the world of galls such as the identification and separation of the gall wasps into different species.
Only his passion to study gall wasps can pull graduate student Charles Davis from the warm and sunny Southern U.S. to chilly central Pennsylvania. Under the guidance of Dr. Andrew Deans at Penn State University, he plans to study gall inducing wasps belonging to family Cynipidae (tribe Diastrophini) to describe the biodiversity of the genus Diastrophus. “When we think of two separate species, we base it purely on two organisms looking different but now with modern methods like DNA sequencing we find that isn’t the case anymore”, notes Charles.
His work includes comparing morphology between species, studying relationships with their host plants, and creating a phylogenetic tree of these mysterious insects. In addition to morphology, Charles will use molecular and bioinformatics techniques to compare the DNA of wasps belonging to the genus Diastrophus. On being asked why he chose this tribe of gall wasps, Charles explains “Unlike Cynipini, which scientists have heavily studied over the years, the Diastrophini have been quite neglected. There hasn't been a serious study of this tribe in nearly twenty years and majority of the original descriptions go back about a hundred years.”
Charles hypothesizes that there are many more species in the genus Diastrophus than the current number and is eager to report a new species when he finds one. In preparation for this mega study, Charles is currently requesting specimen loans from museums for this comprehensive project. He is always on the prowl for more galls on the plants around State College and beyond. Charles is also reaching out to people on iNaturalist for data, so next time you spot a gall on bushes around you make sure you click a picture and upload it to iNaturalist.
According to Charles, “Wasps are vastly diverse, and we can only estimate the number of species that are present. There could be species diverging this very moment and there not enough trained individuals to study and identify these fascinating insects before the biodiversity is lost”.