Susan Straight of Chilmark has car trouble.

Her vehicle is virtually new, runs fine and she is not known for hot-rodding, speeding or any other activities that would cause any issues. Her problem, it seems, is neither mechanical nor cosmetic.

For the last few weeks, Susan has been noticing that her car is being buzzed by a bevy of yellow jackets. These wasps seem to have taken a liking to the automobile and are crawling all over it all day and Susan wants to know why.

Could it be the color of the vehicle? Is there a nest nearby? Is it a swarming situation? 

Turns out it is none of the above. After observing the phenomenon for some time and being concerned about the possibility of getting stung since there are allergies in her family, Susan sought answers. She reached out to a few pest control companies, but it wasn’t until TJ Hegarty of All Island Pest Management showed up that she had an answer to the mystery of the congregating wasps.

Wasps are known for their aggressive protection of their nest, and colonies peak in August and September. However, no nest was found in the area.  With the coming of cooler weather, the queen will stop laying eggs and the workers will die out as temperatures decline, so a swarm didn’t make sense either. 

These insects can detect colors, and it is believed that they are attracted to bright and dark colors, so pale and muted hues are best to avoid riling them up. The car’s color was not to blame in this case.

It was their meal preferences that were the cause of the creatures collecting on her car. Being polyphagous, these insects consume a variety of foods, and it is their eating habits (and their associations) that were to blame for their automobile affection. In addition to preferring to nosh on live and dead insects, wasps are also frugivores, meaning they like sweets, including fruit, plant nectar and another sugary liquid called honeydew.

Honeydew is a liquid waste produced by aphids, scale insects, mealybugs and a few other species that feed on plant sap. What goes in, must come out and so their consumption of plant juices emerges from their other end as a syrupy excrement. Called trophobiosis, this symbiotic relationship occurs when one organism provides protection in return for the other providing food. The provider of food is the trophobiont in the relationship.

In the absence of rain, the honeydew accumulates on leaves and drips off of trees and from the backsides of the insects producing it. And in this case, it fell on Susan’s precariously parked car, which was directly under a tree that had an infestation of honeydew-producing insects. This sticky sap-like liquid coated her car and attracted the hordes of yellow jackets that were simply enjoying a sweet treat.

TJ tried to reduce the population with a fly swatter, but that was a short-term solution as more wasps just kept coming. Cleaning the car would help, though it would have to be parked a ways from the affected trees. Another option suggested was to cut the concerning tree or treat the tree’s insect invasion.

Susan’s peculiar pest problem was a sticky but solvable situation. Now it is time to get the aforementioned solution to the top of her honey-do list.

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown, and author of Martha’s Vineyard: A Field Guide to Island Nature and The Nature of Martha’s Vineyard.