Pollination After Dark

Madison Jennings measures apple flower nectar samples under a microscope.

Author: Madison Jennings | Major: Biology

My name is Madison Jennings, and I am a biology major investigating the synchronization of nocturnal pollinator behavior and apple flower nectar production, under the guidance of Dr. Erica Westerman. Throughout the 2022 spring grant term I worked to determine the effect of time and weather on the nectar production of apple flowers and the abundance of nocturnal pollinators in an apple orchard.

Ever since I joined the honors college my freshmen year, I looked forward to the possibility of conducting my own research project and began the process of inquiry through my coursework. I joined Dr. Erica Westerman’s lab my junior year after having taken her course, animal behavior. Dr. Westerman’s behavioral research of butterflies sparked my interest in how organisms interact with their environment. Dr. Westerman met with me to discuss our shared interest and brought to light the phenomena of nocturnal pollination. The recent discovery that nocturnal pollinators in an apple orchard provided similar levels of fruit output as diurnal pollinators inspired my curiosity. This led me to investigate the nature and function of behavior that facilitates such plant-pollinator interactions. I aimed to characterize the relationship of nocturnal pollinators and apple flowers by considering whether nectar production encouraged nocturnal insect presence. Nectar serves as a flower reward to support pollination and provides a food resource for pollinators. Given that time and weather can influence nectar production and insect presence, I included such factors in my analysis.

Agriculturalists heavily rely on bee pollinators to ensure crop production despite rapid declines in local bee populations. Nocturnal insects, such as moths, have been traditionally viewed as pests in an agricultural setting, however their significant contribution to apple production offers an alternative method for crop pollination. The implications of my research proposed an exciting real-world application, as the use of nocturnal pollinators may be the key to remediating the effects of declining bee populations and sustaining food production worldwide.

Although the field research was carried out the previous spring season by a team consisting of 6 researchers, including myself, I analyzed the nectar and insect data during the spring semester of my senior year. One of the first challenges I faced was deciding how to measure the 779 nectar samples collected from apple flowers over the field season. I originally intended to measure the nectar by taking pictures of each microcapillary tube using ZEN Blue, a microscope computer software. I would use the program to digitally insert a scale bar and then measure the nectar amount on each picture in a separate program. This effort proved to be far too tedious and time consuming. After consulting with Dr. Neel Joshi of the Entomology department and my mentor, I instead decided to measure the nectar using a dissecting microscope and a manually created scale bar on a sheet of paper. This allowed me to accurately measure the nectar at an efficient pace. I determined that nectar was produced by apple flowers consistently throughout the day and night. I also experienced difficulty in analyzing the insect and nectar data due to uneven sample sizes of sampling times. As a result of inclement weather, some of the sampling times during insect collections and nectar sampling were canceled, making it difficult to compare insect presence and nectar amounts at similar times. To control for bias, I excluded unpaired insect and nectar values from the dataset. The results of the linear regression concluded that nectar production and insect abundance were not correlated, however transect insect abundance was significantly affected by temperature and wind.

Although there was not a synchronous relationship between nocturnal insects and apple flowers, I feel my research is still valuable as it provides insight into the workings of this understudied system. One lesson I have learned throughout my research experience is that “good science” is not proving a hypothesis correct or uncovering a groundbreaking discovery, but it is answering your research question. The beauty of science is that any result, expected or not, can further our understanding of the world and it is often the unexpected result that expands one’s thinking and continually inspires the process of scientific inquiry.

Following graduation, I will continue to pursue research opportunities and hope to work in a biology lab while I prepare to apply to medical school. I plan on applying to medical school next year with the dream of one day becoming a pediatrician. I am thankful for this research grant that has allowed me the opportunity to conduct an independent research project during my undergraduate career, providing me invaluable learning experiences to assist me in my future endeavors.