Entomological Invasion

A wheel bug striking a menacing pose-whatsthatbug.com

A western conifer seed bug spotted in Maine-wikipedia.org

They come from as far as the ends of the Pacific Coast to the lowest tips of the Florida peninsula. 
Though they are easily mistaken for other more common insect species and tricky to spot in the 
wild, do not be fooled—these bugs are at large and growing faster every day. The docile western 
conifer seed bug and the ravenous wheel bug are abundant throughout southeastern Pennsylvania, despite residents being largely unaware of their presence.            

Even our astute DC students had trouble identifying these fascinating creatures; in a recent survey, only four out of ten students claimed to have seen a western conifer seed bug, though none knew what it was. When asked about wheel bugs, all the students responded with a blank stare or a confused look. So what exactly are these engrossing arthropods and how can their sudden population boom be explained? Enter local biologist and former DC teacher Mr. Dan Correia.            

According to Correia, the western conifer seed bug is often mistaken for your everyday brown marmorated stink bug due to the former's brown exterior and the awful stench that it emits when threatened. This invader arrived in Pennsylvania in 1992, most likely due to western shipping to the eastern states, and has continued to spread all over the world. 

While seed bugs are slightly larger than stink bugs and harmless to humans, they are harmful to the environment. As Correia explained, “They are nothing more than [a pest] to people, but [they] can do great damage to Douglas fir trees and other pines by destroying the cones. Some of these soft wood trees are very important to the construction industry and other manufacturing markets.”            

Unlike the seed bug, the wheel bug is a common species native to the eastern United States; however, its camouflaged exterior and shy nature makes it tricky to spot in the wild. The wheel bug—named after the wheel-shaped structure on its backs—is a species of “assassin bug” that preys on pest insects such as honey bees, caterpillars, and aphids. 

“The wheel bug is one of the largest species in the Hemiptera order that contains assassin bugs,” commented Correia, who had recently captured and studied a wheel bug near his home. “It is predacious and is one of the angriest bugs within the insect realm. It can inflict a nasty bite, using its harpoon-like proboscis to shank its victims and then suck out their innards, which is pretty awesome.” 

Though wheel bugs are beneficial to humans in that they eliminate pests, one must take caution  in the presence of this aggressive species. They will bite if provoked, which can cause tissue necrosis or even heart failure. Moreover, the wheel bug's bite is far more painful than a bee sting.             

So, the question looms: will the seed bug, wheel bug, or both become as numerous as the stink bugs of 2010? Correia believes that while it is possible for both to rise to colossal numbers, such  proliferation would ultimately depend upon how much sustenance each species obtains in our area. “Well, I think it is completely possible for either species to become as prolific as the dreaded stink bug. In the case of the seed bug, its survival would really depend on there being enough conifer trees to support an ever-growing population.”

Correia added, “Due to their ability to destroy seed outputs of trees, I suppose it would be quite possible for [seed bugs] to ‘kill off’ their food supply. Wheel bugs, however, depend more on [the amount of] ample prey. I believe that as long as they have enough food and more and more can survive the climate further north, they should be good to go.” 

All that said, eastern Pennsylvania residents may have to learn to endure a new pair of entomological interlopers in their midst.