CAREER: Development and Evolution of Wing Polyphenism in a True Bug

Colby College, Waterville ME

Investigators

Abstract

Insect species with wing polyphenism grow to two distinctly different adult wing sizes, with distinctly different anatomical patterns. Therefore, while humans have a single developmental pathway to the size and pattern of the adult body and organs, the developmental process must diverge for different individuals of polyphenic insects. The importance of growth regulation to human health makes studies of polyphenic organ size potentially transformative. How is one form specified and realized in each individual? How does this ability evolve in the species where it occurs? How can alternate wing sizes affect the spread of insects into new habitats? This project seeks to understand the cues and alternative developmental processes that result in differently sized and patterned wings of a native Florida insect, the red-shouldered soapberry bug (Jadera haematoloma). This project will use high-throughput sequencing to compare the expression of genes in bugs of each wing pattern. For selected genes, functional tests will examine their interactions and roles in regulating organ size and wing pattern. The evolution of polyphenism will be explored by laboratory selection on wing size variation in soapberry bugs and in a related insect, the large milkweed bug (Oncopeltus fasciatus), which normally grows to a consistent adult wing size and pattern. This work will be conducted largely by undergraduate students, as part of an integrative curriculum that combines hands-on work in molecular genetics, evolutionary biology and ecology with related social science and humanities courses related to urban life and adaptation to new environments. Public K-12 students and teachers will assist in field surveys of the bugs to determine how wing sizes correlate with their northward expansion from Florida up the East Coast. Project personnel and undergraduates will exchange knowledge and experiences online to illustrate the process of scientific research to younger students.