September brings all sorts of changes to the countryside. By the end of the month the green ash will have turned from shiny green to glowing yellow. Poison ivy changes from green to international orange or sintering red. Most all the migratory songbirds depart in September while the northern birds arrive. Some of my favorite berries and fruits — wild plums and elderberries — ripen, as well.
One aspect of September changes that I don’t appreciate is that yellow jackets become aggressive. I don’t know if it’s my imagination or what, but it seems that I have been stung and harassed by yellow jackets more in September than any other month.
I was curious about the phenomenon, so I looked up yellow jackets on Wikipedia and discovered a lot. First off, yellow jackets belong to the genus Vespula of the order Hymenoptera (social insects). In many places, yellow jackets are called wasps. Most species are yellow and black, but some, like the bald-faced hornet, are black and white.
Yellow jackets are predatory insects and feed on other insects — many of them pests. Yellow jackets’ strong mandibles enable them to eat their prey and also to chew up wood and other fibers to be used in nest construction.
Yellow jackets have a lance-like stinger with barbs on it. They can sting repeatedly, though sometimes the stinger becomes lodged and breaks off. The venom isn’t dangerous to a human unless a person is allergic to it or repeated stings. (Having been stung many times by yellow jackets, I know that I am not allergic, but the multiple stings hurt like the dickens.)
Some yellow jackets make nests in trees, bushes, house eaves, walls, or in cavities or burrows in the ground.
According to Wikipedia, “Yellow jackets are social hunters that live in colonies that contain workers, queens, and males. Colonies are annual and only inseminated queens overwinter.” The fertilized queens seek out protected places such as under bark, hollow logs, stumps and manmade structures. The queen emerges in late spring and builds a paper nest where she lays eggs. About 30 to 50 brood cells are made. When the larva hatch the queen feeds them for about 18 days. The larvae pupate and emerge as sterile females or workers.
The workers tend the developing larvae by feeding them chewed up food. The workers also expand the nest, tend the queen and defend the nest.
The queen stays in the nest and continues to lay eggs until her death in the autumn. The colony expands rapidly and can reach a population of 4,000 to 5,000 workers by summer’s end. The workers construct reproductive cells in which new males and queens are produced. The workers feed the reproductives until they fly off to mate in the fall. After they mate, the males quickly die. After the reproductives leave the nest, the workers slowly dwindle in numbers and eventually fly off and die as does the original queen. The new queens seek out places to overwinter and start the cycle all over next spring.
Adult workers feed on sugars and carbohydrates while the developing larvae feed on proteins. The workers chew up meat, insects and fish and feed it to the larvae. The larvae in turn secrete a sugary substance that the adults eagerly feed on. At the end of summer when the larvae no longer secrete the sugar, the adults turn to foraging for ripe, decaying fruits, garbage dumps and the stuff of human picnics — sodas, watermelons, etc.
Ah, it’s taken me this long to realize that the yellow jackets are nuisances because they are looking for their favorite sugars. No wonder they come around when I open a cola, slice up some cantaloupe and enjoy an apple. It really gives me no comfort that they will be dead in a month or two.
Oh well, I have to remember to watch out when I drink from a soda or beer can that a yellow jacket hasn’t flown into it. I have found out that getting stung on the lip is a lot more painful than being stung on the arm.
Take care this September and watch out for yellow jackets. Don’t let their stings ruin a great day out-of-doors.