Shipments of more than 2,600 General Motors SUVs were delayed after bugs left a 'stubborn black residue' on them

• Shipments of more than 2,000 General Motors SUVs were delayed after mayflies landed on the vehicles, leaving behind greasy residue, according to a report from Automotive News.
• Approximately 2,600 GMC Yukons and Chevrolet Tahoes assembled at GM's Arlington, Texas, plant were affected.
• GM said all the vehicles will be cleaned by the middle of September.

It's totally normal for new cars to leave the factory with a bug or two, hence the warranty periods. But for a few new General Motors SUVs, the bugs weren't exactly metaphorical.

Automotive News reported Monday that actual insects — mayflies, to be specific — caused delivery delays and plenty of other problems for thousands of SUVs coming out of GM's Arlington, Texas, plant. Automotive News described a "stubborn black residue" that the bugs left on more than 2,600 Chevrolet Tahoes and GMC Yukons, which were parked and waiting to be shipped to dealers.

The Tahoe and Yukon are some of GM's most profitable vehicles, and dealerships were already struggling with low inventories amid their summer launch due to pandemic-related production slowdowns.

A GM spokesperson told Business Insider that the residue was a result of mayflies landing on the vehicles and sticking to them. The SUVs were being stored near a lake, where the mayfly population has ballooned due to higher temperatures as of late, the spokesperson said.

"Plant personnel are rapidly cleaning vehicles so that they arrive to our dealers and customers in flawless condition," the spokesperson said, noting that the mayfly situation "has been addressed had a very minimal impact on our launch."

GM sent out a bulletin to GMC and Chevy dealers describing the issue and instructing them how to clean the greasy substance off of vehicles, Automotive News reported. According to the report, some dealerships spent hours cleaning vehicles, and one Tahoe's hood was so damaged that it has to be repainted.

Fewer than 100 of the buggy SUVs arrived at dealerships before being cleaned, and all the vehicles will be scrubbed down by mid September, a GM spokesperson told Business Insider.