IS A WHITE COCKROACH AN ALBINO COCKROACH?First, it’s important to note that these are two different conditions. As common as white cockroaches are, there has never been a documented case of an albino cockroach, at least not one that fits the definition of albinism.
According to the National Organization for Albinism and Hypopigmentation, albinism is a genetic condition that affects an organism’s ability to produce a sufficient quantity of the pigment melanin, the material that gives color to the skin, hair and eyes. There are many levels of albinism and it doesn’t always result in noticeable non-pigmentation of the skin and hair, but almost always affects vision.
An accurate diagnosis is not reliably made by observing the color of the skin. Instead, it is most commonly diagnosed by a simple eye exam. But don’t open up a cockroach eye exam center just yet. Albinism is not a genetic condition that is known to affect roaches. In other words, when it comes to a white cockroach, albinism is not the cause.
WHAT CAUSES WHITE COCKROACHES?The real cause of a cockroach’s white appearance is that when roaches molt, they don’t only shed their outer shell, they also lose most of the pigmentation in their bodies, which must then be replaced. This is a chemical reaction that occurs within the body, usually taking a few hours to fully restore pigmentation. The pigmentation not only colors their bodies, it may affect their circadian rhythms, or biological clocks, according to a study on the neural organization of the circadian system of the cockroach Leucophaea maderae.
WHY DO YOU RARELY SEE A WHITE COCKROACH?Cockroaches are arthropods, and just like all arthropods, they don’t have a spine, making them invertebrates. In fact, cockroaches don’t have any other bones either. But in order for a cockroach’s muscles to properly operate their legs, wings and other moving parts, they have to be attached to something rigid. This is why insects have hard outer bodies.
This exterior skeleton, or exoskeleton, provides the structure their bodies need to operate properly. Because the exoskeleton is rigid and cannot change size once it is “set” on the insect, cockroaches must get larger and grow by a process called “molting.” Molting is when cockroaches periodically shed their exoskeleton, replacing it with a roomier model that allows them the internal space they need to continue growing.
Before they shed their old outer shell, or skin, they must form a new one, just inside the old one, to keep their body parts together and retain body moisture when they molt. This new skin, or exoskeleton, is soft and pliable at first and has no pigmentation, which is what gives the shell its color. When roaches are ready to molt, they split the old skin and crawl out of it. The new skin is ready to go, but it is still very soft. Because the pigmentation process has not yet been completed, the new skin is also white.
Roaches are highly vulnerable to drying out and to attack by predators just after molting, so roaches that have molted stay hidden, out of the light and moving air. The new shell is not rigid enough for the muscles to provide much movement at this point, making it hard to run and hide when predators are chasing them. These factors, combined with the possible disorder of their biological clocks, provides plenty of incentive for roaches to stay out of your sight while they’re white.
WHAT HAPPENS TO THE WHITE COCKROACH NEXT?The exoskeleton will start to harden and regain normal coloration over the next few minutes, and life will soon return to normal for the temporarily white cockroach. Some species of roaches may take several hours to fully transform. At this point, the cockroach, now sporting a new suit of armor, is ready to go find food, water and shelter. If this is their final molt, the cockroach has reached adulthood and a mate will soon be located.
WHY WOULD I SEE A WHITE COCKROACH?All roaches are white cockroaches for a short period of time, every time they molt. They stay in deep harborage areas for protection when they feel a molt coming on, so if a white cockroach is observed, something has disturbed the harborage area. Professional pest control technicians see white roaches quite often as they apply treatments deep within harborage areas. This disturbs them during the molting process, running them out of hiding places and ensuring that cockroach control will be successful.
Chronobiol Int. 2003 Jul; 20(4):577-91. Neural organization of the circadian system of the cockroach Leucophaea maderae. Homberg U1, Reischig T, Stengl M.