Alarmed Aphids in My Garden

Squishing really does cause "alarmed aphids" to fall off plants and walk away. An OpenAI story at the end.

Alarmed Aphids 

Years ago, I mean decades ago, I used to have a garden plot at the University of California, Riverside. It was free. I knew nothing about gardening. But if I found aphids on my plants I used the oldest method in the book to get rid of them. I carefully put the leaf between my index finger and thumb, and then squished the aphids. Little did it occur to me that there might be science behind this method and that I had "alarmed aphids."

As I was squishing the aphids,  I was doing graduate research in entomology at UCR. I was studying the sexual disruption of the pink bollworm in the cotton fields of the Coachella and Imperial Valleys using pheromones released in micro-tubes. Pheromones are species specific chemical messengers. In this case we were able to reproduce the pheromone produced by the female moth that said "Here I am!" The micro-tubes were released from low flying planes. The pheromones saturated the fields and pretty much prevented males from finding female moths in the fields. I did not realize that at the same time as I was doing my research, researchers in Ohio were studying aphid pheromones.

Aphids are expert feeders and breeders. During a growing season, female aphids will give live birth as seen in this 3 minute video I filmed two weeks ago. If you carefully look at the aphid in the top right, you will see the young aphid emerge.

This is asexual reproduction. The young are females that quickly mature into live birthing adults. This is why you will see masses of aphids in a single location. They did not walk to the same place, they were probably born there. I saw a quote from the book by Stephen A. Marshall, "Insects: Their Natural History and Diversity​" that under ideal conditions (such as no predators) a single aphid could produce 600 billion decedents in a single season. 

It is only when the population is stressed that the females will give birth to nymphs that will be winged or male.

At the Townhouse Gardens I use four methods to control aphids:

1. Encourage predators and Free Food! Grow plants nearby such as nasturtiums and other flowers that can tolerate large populations of aphids. These populations of aphids will feed and attract predators such as lady bird beetles and lacewings.
2. Wash the garden with a low concentration of soapy water using a hose sprayer. This loosens the aphids and in some cases can desiccate the aphids. It also controls spider mites.
3. Control ants. Ants like to "farm" the aphids for their waste which is high in sugar and nutrients. In return, the ants protect the aphids from predators. I use ant traps on the patio to poison ant colonies. I also use a combination of tape and tanglefoot to keep the ants off the trees.
4. Squish Method

It turns out there is science behind the last method. It relates to the research I did as a graduate student. Aphids also have pheromones. In response to a threat, like being squished or a predator, alarmed aphids release an alert pheromone. Alarmed aphids will drop off the plant and walk away. https://pubmed.ncbi.nlm.nih.gov/20831961/

Reproducing this "alarmed aphids" pheromone into a chemical spray is difficult since the chemical breaks down rapidly. Also pheromones are very species specific so a spray would only work on a small group of aphids. But rest assured that when you squish those aphids, you are sending a message to the alarmed aphids: "Get moving!"

Diversion

The above was written by a human. But as a tech guru I am fascinated by the possibilities of OpenAi's ChatGPT. I asked it to "Write a story about an ant falling in love with an aphid." The image was created by OpenAI's Dall-e-2 with the prompt "an ant and aphid in love as painted by DaVinci

Once upon a time, in a bustling ant colony, there was an ant named Alex. Alex was unlike any other ant in the colony because he had a special fondness for the aphids that lived in the nearby gardens. 

Every day, Alex would venture out of the colony to visit the aphids. He would spend hours sitting beside them, listening to their gentle hum and admiring their delicate wings. While the other ants would be busy gathering food, Alex would be lost in his admiration for these little creatures. 

One day, while sitting beside his favorite aphid, Alex realized that he was feeling something more than admiration. He was falling in love with the aphid. 

At first, Alex was unsure of what to do. He knew that ants and aphids were not supposed to be together, and his love for the aphid seemed impossible. But despite his doubts, Alex couldn't help but feel drawn to the aphid. He decided to take a chance and express his feelings to her. 

To his surprise, the aphid felt the same way. She had noticed Alex's visits and had grown fond of him too. The two began spending more time together, and their love blossomed. 

As they spent more time together, Alex and the aphid faced many challenges. The other ants in the colony were not pleased with their relationship and thought it was a disgrace to the colony. But Alex and the aphid didn't let that discourage them. They stood by each other and refused to let the opinions of others determine their happiness. 

Despite the challenges, Alex and the aphid's love continued to grow stronger. They would spend hours talking and enjoying each other's company. They would sit together, gazing at the stars and dreaming of their future together. In time, Alex and the aphid decided to leave the colony and start a life together. They found a cozy spot in the nearby gardens and built a little home for themselves. They lived happily ever after, with their love for each other growing stronger with each passing day. 

And so, Alex the ant and his beloved aphid showed that love knows no boundaries and that sometimes, the most unexpected love stories can be the most beautiful of all.