The Trump administration and Republican allies are blaming former President Joe Biden after the New World Screwworm (NWS) was detected in U.S. livestock for the first time in decades.

The Agriculture Department announced last Wednesday that the flesh-eating parasite had been found in a calf in Texas for the first time since 1966. There have been four total confirmed infections in Texas since the NWS return.

Critics have blamed the Trump administration and Elon Musk’s Department of Government Efficiency (DOGE) for the parasite’s return, noting that DOGE gutted the United States Agency for International Development, which included a program dedicated to preventing the spread of the parasite across the U.S.-Mexico border.

At the time, officials in Texas were raising concerns about the pest’s steady movement through Mexico toward the US border. The parasitic fly’s larvae burrow into the healthy tissue of cattle, deer, horses and other warm-blooded animals, according to the USDA.

“For months, the screwworm has advanced rapidly through Mexico in spite of the USDA’s existing game plan,” Texas Agriculture Commissioner Sid Miller told NBC News, adding that “instead of using every available tool, USDA moved too slowly and relied solely on a partial solution that takes years to fully implement.”

But, Trump officials and their Republican allies on Capitol Hill claim the outbreak is Biden’s fault because migrants who entered the country under his watch brought the disease with them.

“New World Screwworm Rapid Response,” the Twitter account from the USDA claiming to provide “the most up-to-date & accurate information on the New World Screwworm,” declared that “the ghost haunting us ISN’T funding, it’s the Biden Border Crisis,” adding that screwworm “broke past Panama into MX bc Biden let millions illegally pour into our country.”

Screwworm was eradicated in the US for more than half a century before the DOGE cuts in the second Trump administration.

Agriculture Secretary Brooke Rollins doubled down on blaming the Biden administration in an appearance on CNBC’s ‘Squawk Box’ on Monday.

“I do think it’s important to note that under the last administration, with a massive movement under the open border policy, the cartels, etcetera, border security, that’s when it began to make its way back up to America,” she said, adding that “not much had been done to push back” before Trump took office.

Republican Sen. Roger Marshall (KS) also blames the Biden administration.

“This is another thing we can thank Joe Biden for,” Marshall told Newsmax. “When millions of people came out of Central America, they brought this screwworm with them. It was on their pets, maybe on their flesh as well. But that’s– we had it contained to Central America.”

According to the CDC, New World screwworm infestations begin when a female fly lays eggs on open wounds or other parts of the body in live, warm-blooded animals. One female can lay 200 – 300 eggs at a time and may lay up to 3,000 eggs during her 10- to 30-day lifespan.

Eggs hatch into maggots that burrow into the wound to feed on the living flesh. After feeding for about 7 days, larvae drop to the ground, burrow into the soil, and emerge as adult screwworm flies.

Biden left office over 500 days ago. If the average life span of a female fly is 30 days, it defies logic that the first case of NWS detected in the US nearly two years into the Trump administration is Biden’s fault.