The German cockroach has developed a strong resistance to insecticide due to the widespread use of chemical bug sprays, according to a research led by Purdue University in Indiana.

印第安纳州普渡大学的一项研究显示，由于化学杀虫喷雾剂的广泛使用，德国小蠊对杀虫剂已产生了很强的抵抗力。

The German cockroach is one of the most common black beetles living around us. It can pose a threat to people's health, as it can trigger allergies and asthma.

In the study, the researchers used individual and combination insecticides, but nothing could wipe out the population of German cockroaches.

"Cockroaches developing resistance to multiple classes of insecticides at once will make controlling these pests almost impossible with chemicals alone," said the research report published in the journal Scientific Reports.

The scientists from Purdue University said the super-immunity gene is passed on to the insect's offspring, so people need to find non-chemical measures to control cockroach populations, such as traps.