Flesh-eating screwworm infection confirmed in South Texas, USDA says

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The USDA’s $750 Million Defense in South Texas

The confirmation of New World screwworms in South Texas represents a critical failure in biological containment. To counter the infestation, the USDA is constructing a $750 million sterile fly production facility in the region, a massive capital investment intended to weaponize the parasite’s own mating habits against it. The strategy relies on the Sterile Insect Technique (SIT). By releasing massive quantities of sterile male flies, the USDA can effectively “elbow out” fertile males. Because females generally mate only once, these “dud studs” prevent the population from regenerating. The scale of the current operation is immense: officials are currently dispersing 100 million sterile insects per week across Mexico and along the US-Mexico border. In the immediate vicinity of the detection, the USDA has already released 4 million flies by air this week and is supplementing those efforts with ground release chambers. “The United States has defeated this pest before, and we will do it again,” Dudley Hoskins, Under Secretary for Marketing and Regulatory Programs at the USDA

The Breach of the Darién Gap

This is not the first time the US has faced this threat, but the current breach highlights the fragility of biological barriers. Screwworms were eradicated from the US in the 1960s, and the effort eventually extended across Central America, leading to their eradication from Panama in 2006. For years, the line was held at the Darién Gap, the dense jungle border between Panama and Colombia. The USDA partnered with Panamanian authorities to maintain a sterile fly production facility at this gap, creating a biological wall that kept the parasites at bay. That wall crumbled in 2022. Since the barrier was breached, the population has moved relentlessly northward.

The Biological Target: Defining “Flesh”

To understand the horror of a screwworm infestation, one must understand exactly what the parasite targets. In biological terms, as noted by the Cambridge Dictionary, flesh refers to the soft tissue of a vertebrate—specifically the skeletal muscle and fat that cover the bones. The screwworm does not merely scavenge dead tissue; it invades living flesh. This distinction is vital. While some tissues are purely fatty, the “flesh” the screwworm consumes is primarily muscular tissue. This is the same tissue that The Free Dictionary defines as the soft part of the body, distinct from bone and viscera. The biological makeup of this tissue is what makes it so nutrient-dense for the parasite. The red color of this muscle is driven by myoglobin, a richly pigmented protein. “Muscle’s red color can be traced to the presence of a richly pigmented protein called myoglobin and, more specifically, hemes,” the chemical compounds that myoglobin uses to bind and store oxygen as a fuel source for active muscles. Robbie Gonzalez, via Smithsonian Magazine In humans, the concentration of myoglobin in muscle is around 2 percent, a level significantly higher than that found in cows, sheep, or pigs. This high oxygen-binding capacity makes the tissue visually similar to beef, though its chemical composition is distinct.

Visceral Realities and the Composition of Tissue

The biological nature of the “flesh” being targeted by these parasites has been documented not only in veterinary science but in the macabre annals of human history. Because human muscle is so similar to other red meats, those who have consumed it often describe it in culinary terms. According to Smithsonian Magazine, accounts vary wildly. Armin Meiwes, a German cannibal, described the taste as being akin to pork, though he noted it was “a little bit more bitter, stronger.” Meiwes concluded that “it tastes quite good.” Other accounts suggest a different profile. William Seabrook, a journalist who traveled to West Africa in the 1920s, claimed the tissue was more comparable to veal, describing a central slice of a roast as tender in color, texture, and smell. However, the validity of Seabrook’s account is contested. Brian Palmer noted that Seabrook later confessed the tribesmen he visited never actually allowed him to participate in their traditions, leading Seabrook to claim he instead obtained samples from a Parisian hospital. Whether the tissue tastes like pork or veal is a macabre curiosity, but the underlying biological fact remains: the screwworm is an expert at dismantling this specific, protein-rich, myoglobin-heavy tissue. The stakes in South Texas are therefore not just agricultural, but visceral. The USDA is fighting a war against a parasite that views every living creature—from livestock to humans—as a source of the very “flesh” that defines vertebrate life. The success of the $750 million facility will determine whether this biological breach remains a localized incident or becomes a systemic collapse of the North American biological barrier.