On Super Bowl Sunday as much of America enjoyed the biggest of all football spectacles, Bug of the Week enjoyed investigating a Super Bowl - sized insect nest, one of the largest we ever seen. Discovered beneath an overhang of our neighbor’s home during a recent renovation, this was an abandoned nest of European hornets. Constructed of beautifully contrasting bands of fine brown paper, this magnificent creation contained hundreds of empty chambers - the former nursery for legions of ferocious hornets. European hornets were first introduced to the United States in New York from Europe sometime between 1840 and 1860. These marvels spread and now occupy territory from the east coast to the Mississippi. In nature these giants of the hornet world use a cavity in a tree for constructing a nest, but occasionally, as was the case with my lucky neighbors, hornets will nest in a wall void of a home or barn.
The colony is founded by a single queen that survives the harsh winter beneath the bark of a fallen log or in another protected location. In spring when warmer temperatures prevail, she will become active, gather bark from a tree, construct a small paper nest, and lay eggs destined to become workers. After the queen successfully raises her first batch of sterile female workers, she remains in the nest producing brood while her daughters take up tasks of enlarging the nest, protecting it, and gathering food for the young such as caterpillars, flies, grasshoppers and other stinging insects like yellow jackets. During late August and early September, the colony operates at a fevered pace. Inside the colony, the queen no longer produces sterile daughters. She has shifted production from workers to female and male hornets capable of reproducing. Females are destined to become the queens of future generations. Males have just one purpose and that is to mate with the new queens. After fulfilling this biological imperative, males die. As autumn winds down, the colony is abandoned and queens find protected places to spend the chilly months of late autumn and winter. The nest will not be reused in subsequent years.
Avoiding stings
Although these hornets are large and scary looking, humans are unlikely to be stung by European hornets unless the nest site is disturbed or attacked. I photographed hornets at a distance of less than a foot as they feasted on fallen pears. To avoid being stung, simply avoid disturbing the nest site. European hornets are somewhat unique in their feeding behaviors in that they hunt at night. They are also attracted to light and can be found buzzing around porch lights or heard crashing into windowpanes at night. They feast on fallen fruit. To construct the beautiful paper nest, European hornets strip bark from several types and trees and shrubs including lilac, birch, and rhododendron. Apparently, this annoying behavior provides the material for making paper and allows them to feed on the nutritious sap and plant tissues beneath the bark. Unfortunately, small plants may be severely damaged by this bark stripping. If European hornets have nested in a home or another location that poses a threat to human health or safety, they may be exterminated with insecticides. However, I favor the approach of my neighbors who had a “live and let live arrangement” with these giants.
References:
Special thanks to the Brooke and Ruth Ann for sharing the ginormous hornet’s nest for this Bug of the Week. For more information on these interesting insects, please visit the following web sites.
http://www.uky.edu/Ag/Entomology/entfacts/struct/ef600.htm
http://ohioline.osu.edu/hyg-fact/2000/2128.html
http://www.vespa-crabro.de/hornets.htm
http://www.agnr.umd.edu/MCE/Publications/PDFs/EB248.pdf
http://www.ces.ncsu.edu/depts/ent/notes/Urban/eurohornet.html