The locust virus was a computer virus. It was created by Ian Webster.
This virus could be downloaded to any computer. After the download the computer would rebuild itself as a metal locust. It would attack the persons around them, get inside their body and make the creator able to take control over the person's mind. Later the system was advanced, instead of one locust, two locusts were built out of the computer parts.
Ian Webster was bullied since his childhood and wanted to take revenge for this. In 2009 the Umorgus came to Earth and told him that they would help him with his revenge. They suggested that he could create a computer virus that made him able to take control over the people that had bullied him before. Ian created the computer virus. He enjoyed to be able to tell his colleagues what they had to do, but he didn't knew that the Umorgus wanted to use the virus to control over the world. When he realised it, it was already to late and the Umorgus already had taken control over Ian. The virus could only be stopped by Sarah Jane Smith and her friends. (AUDIO: Deadly Download)