While southern California’s pleasant year round climate and beautiful mountainous scenery make the region an ideal place to live for many people, numerous arthropod pest species cause a lot of problems for homeowners across the entire state. The most common insect pests found in southern California homes include termites, ants and cockroaches. Homes often become infested with both native and invasive pest species belonging to all three of the above mentioned insect groups. For example, several native termite species, such as western subterranean and western drywood termites can be found in southern California, but so can the particularly destructive Formosan subterranean termite species, which is an invasive pest that originates from southeast Asia. Like all US states, native pavement ants and odorous house ants are common indoor pests in southern California, but so are invasive red-imported fire ants and Argentine ants, the former of which inflicts deadly stings in the state every year. Technically, all cockroach pest species in the US are non-native, as they arrived in the country centuries ago, but the Turkestan cockroach species is a relatively recent member of southern California’s roach community. This exotic roach species possesses unique traits that make them particularly unpleasant home invaders, and they are rapidly displacing other cockroach pest species throughout southern California.
The Turkestan cockroach was first discovered in the US when military personnel discovered specimens at a military depot in Lathrop, CA back in 1978, and since then this species has expanded its invasive habitat across much of the southwest. The Turkestan cockroach recently replaced American, Oreintal and other common cockroach pests as the most common peridomestic cockroach pest species in the southwest. This species’ rapid takeover in the southwest can be explained by its ability to reproduce in large numbers, and their hardiness when exposed to extreme climatic conditions. In southern California, Turkestan cockroaches are being found in sewer systems, below leaf-litter and near small water sources in residential and urban areas, but they are found in homes just as often as they are found outdoors in the state. Most cockroach pest species, like American, German and Oriental cockroaches, are unable to scale smooth vertical surfaces, and this is why roaches often become stuck in bathtubs, sinks and even toilets. However, the Turkestan cockroach is blessed with more adhesive feet that allow them to scale just about any surface. This is why these cockroaches are frequently found resting behind hanging framed photos. Turkestan cockroaches are around a half an inch in length with a brown to black exterior, and large numbers often congregate under and behind baseboards and door frames, wall voids, around hot water tanks and sinks, drains, and in drop ceilings.
Have you ever spotted a cockroach resting on a wall or any other vertical surface?