Las Vegas expected another night of swarming grasshoppers after a Nevada state entomologist warned residents and visitors they will be around for a few weeks. Picture: Benjamin Hager/Las Vegas Review-Journal via AP

Washington - Las Vegas expected another night of swarming grasshoppers on Saturday after a Nevada state entomologist warned residents and visitors they will be around for a few weeks.

Photos and videos of grasshoppers flying under the lights of casinos along the city's Strip of hotels and entertainment venues began appearing on social media earlier this week.

People commenting about the insects on Twitter compared the situation to scenes from horror films and referred to biblical passages about signs of the apocalypse.

But Nevada state entomologist Jeff Knight said residents and visitors needn't worry. The bugs don't carry diseases or bite and "probably won't" cause any damage to foliage, Knight said in a blog post.

"They generally just eat weeds," Knight said. "When there are so many, they tend to move and are headed north," he added, saying they are likely to be around for a few weeks.

Knight said the insects are a common desert species known as pallid-winged grasshoppers that are numerous as a result of wet weather during winter and spring. They grew in number in northern Arizona before beginning their migration northward, which brought them into southern Nevada.

They are especially prominent at night in the gambling mecca because they are attracted to bright white ultraviolet lights. Officials said people who want to keep them away can change their outdoor lighting to a low ultraviolet or amber light.

Similar grasshopper swarms have occurred four or five times in the last 30 years in Las Vegas, according to weather records.

dpa