German Cockroach (Blattella germanica)
A species of small cockroach, German cockroaches are roughly .5” long at maturity. Primarily varied shades of tan, it has two distinctive dark streaks that run parallel along its back. Often confused with the Oriental cockroach due to their similar appearances, German roaches are a bit wider where Oriental roaches are narrower with longer wings. The easiest way to tell the difference is in their behavior—German roaches rarely fly and prefer the dark while Oriental roaches will fly towards a light source. Additionally, German roaches typically set up their harborages indoors, while Oriental roaches are outdoor pests that are drawn inside by lights or to scavenge.
German cockroaches are indoor pests, struggling to survive in temperature extremes. They typically harbor indoors, often in cracks, crevices, and other dark, tight spaces. In homes, German roaches are often found in kitchen cabinets, under sinks, behind appliances, or near pipes; they gravitate towards warm, humid spaces that have easy access to food and water. Research suggests that they rarely go more than 15 or so feet from their colony’s harborage when they have adequate access to resources. As a small species, they are able to harbor in spaces where larger roaches would not fit. German cockroaches are typically difficult to eradicate. That difficulty stems from their rapid breeding cycle and their ability to develop resistance and/or aversion to several types of pesticides. German roaches have one the fastest reproduction cycle of any domestic species, growing from egg to adult in 50-60 days in ideal conditions and with females able to carry an average of 32 eggs at a time.
Combating a German roach infestation takes sustained effort. Prepare your customers for follow-ups for the next 2-4 months to ensure eradication of the current population and any eggs that survive to produce the next generation. Gel baits for cracks and crevices can help. Keep an eye out for signs of pesticide resistance and rotate baits (in terms of active ingredients and bait matrix) to combat both resistance and aversion. Dusts can be used behind and under appliances or in wall voids. Products with borates are a good option because no insect population has been known to develop resistance to them while the use of insect growth regulators helps control for future generations. Work with your customers to ensure better cleaning habits that focus on reducing their access to food and water. In multiple housing units, mechanical interventions like caulking cracks and crevices can help prevent populations from migrating.