We all know that the most sly and sneaky creepy crawler out there is the cockroach. This bug will eat our pizza or snickers bar if open and left out; it will even raid our pantries and refrigerators. Over a span of many years this bug has put up quite a resistance in the war against mankind. The roach is one of the most exterminated bugs by pest control professionals, but in the 1990’s in Florida, some of the exterminator’s tricks stop working. This was because the roaches developed a trick of their own; ditching their sweet tooth.
One of the professional tactics used against cockroaches is baiting them with a sweet, sugary poison. In the 90’s when this bait stopped working, researchers started speculating about this seemingly invincible pest. How had the bug avoided the sweet scent and taste of the concoction? Researchers from Raleigh’s North Carolina State University, Ayako Wada-Katsumata, Jules Silverman, and Coby Schal looked into that very question.
Using the common German cockroach, researchers studied the reason for this change in roach behavior. Roaches use taste hairs all over their bodies instead of taste buds to taste their food. Researchers focused on the taste hairs around their mouths and two types of nerve cells that transmit signals to the brain. One of these transmits the taste of bitterness, while the other transmits the taste of sweetness. When the brain received the sweet signal, the roaches were, of course, inclined to eat the substance, and when it received a signal of bitterness, the roaches laid off. The three researchers from North Carolina determined that glucose, which is the main ingredient used in most sugary products, stimulates the bitter receptor in the roach’s brain.
Entomologist at Purdue University, Grzegorz Buczkowski, and Walter S. Leal, the head of the entomology department in the College of Agriculture and Environmental Sciences at the University of California, Davis who were not involved in the research, made some remarks on the findings.
Buczkowski said, “We lose baits all the time.” He expanded by saying that the bug industry has to keep up with the evolution of these bugs in order to maintain the effectiveness of their products. New poisons are constantly developed, because cockroaches and other pests become resistant to the poison, just as bacteria become resistant to antibiotics.
The findings now explain that it wasn’t an ineffective poison, or that the roaches developed immunity to it. The cockroaches simply changed their genetic make-up and lost the attraction to glucose. Now some roaches are passing off this gene and evolving into some sort of super roach.
Walter S. Leal says, “Sometimes the science is beautiful but you don’t know whether there is going to be an application five years from now, 10 years from now or 100 years.”
These results seem to be well on their way to helping the pest control industry and mankind in general to keep a leg up on the evolving cockroach.