It probably won't take much to convince Texans to stay away from the latest invasive species from Mexico, once they hear about the symptoms. Texas Parks and Wildlife Department (TPWD) says to look out for evidence of the New World Screwworm (NWS) affecting animals, especially near the state's southern border.

So far it sounds like the NWS is still relatively far away, having been spotted in a cow at a checkpoint near the border between Mexico and Guatemala. It was eradicated from the United States in 1966, according to TPWD, but it is being tracked northward from South and Central America.

Although it's called a worm, it is really a parasitic larva, and this is where things get disturbing.

Before the "worms" become the NWS fly (Cochliomyia hominivorax), they lay eggs in open wounds or orifices of live tissue. They are called screwworms because they screw into the flesh, worsening injuries and causing a painful condition called NWS myiasis. An infestation can even lead to the death of the animal.

The larvae drop to the ground after feeding, and emerge as flies that can travel long distances, so the movement of livestock — not just contact among them — is a concern.

If you don't own livestock, you're not quite out of the woods. Although the NWS does affect those animals the most, it also affects wildlife like deer and birds, and even pets and humans. Hunters should also keep an eye out, as well as any "outdoor enthusiasts," says the release.

From the release, here are some things to look out for:

• Irritated or depressed behavior
• Loss of appetite
• Head shaking
• Smell of decaying flesh
• Presence of fly larvae (maggots) in wounds
• Isolation from other animals or people

To keep the flies away, especially when traveling to NWS-affected areas like Cuba, Haiti, the Dominican Republic, and South American countries, TPWD says it's important to clean and cover all wounds. Travelers should also use insect repellant on outdoor clothing.

Anyone who suspects signs in wildlife of NWS should report their findings immediately to a local wildlife biologist. Reports about livestock should be directed to the Texas Animal Health Commission (TAHC) or U.S. Department of Agriculture (USDA).

“Those enjoying Texas’ natural resources have an opportunity to serve as the first line of defense in protecting wildlife, livestock, and human health,” said TPWD wildlife veterinarian Dr. J Hunter Reed in the release. “Their eyes and ears will be critical to quickly responding and managing this threat.”