Site of Animal Health Discovery

The sterile fly had to be shown to work on a bench first. After Edward Knipling's theory reached Raymond Bushland, back in Texas at Kerrville, he and D. F. Hopkins used X-ray equipment at an Army hospital in San Antonio to treat screwworms at different life stages. They found doses that sterilized the flies without spoiling their mating behavior. Cage studies mixing sterile and normal flies matched the mathematical models. Field tests began in 1951 on Sanibel Island, Florida, where flies from the mainland partly undid the result. Access to the research center is restricted.

What the plaque says

Site of Animal Health Discovery In this building (at Menard) during late 1930s, Dr. Edward F. Knipling (b. 1909) advanced theory screwworms might be eradicated by releasing sterile male flies to break chain of reproduction and save livestock from role of host to parasitic larvae that destroy livestock and wildlife. During 1950-51, this laboratory (removed to Kerrville area) was site of sterilization of male screwworms with irradiation, in procedures by Dr. R. C. Bushland and D. E. Hopkins. The outcome: eradication of the screwworm and saving of domestic and wild animals of the United States. (1972)

Where it stands

Worth the stop nearby

• Schreiner Mansion — 2.6 mi
  The 1879 downtown home of Charles Schreiner, the Alsatian-born merchant, banker and rancher whose store and mohair trade built Kerrville.
• Treue der Union Monument — 14 mi
  An 1866 German-language monument in Comfort over the graves of Hill Country Unionists killed at the Nueces in 1862, its flag of thirty-six stars kept at half-staff.
• Old Tunnel State Park — 17 mi
  A railroad tunnel abandoned in 1942 that now shelters up to three million Mexican free-tailed bats, who fly out each evening from May through October.
• Fort Martin Scott — 20 mi
  An army post of 1848 on Barons Creek beside the German town, where soldiers kept the peace of a Comanche trade and paid the merchants in hard cash.

More markers nearby

• Captain Joseph A. Tivy — 1.5 mi
• Zion Lutheran Church — 2.3 mi
• Barnett Chapel Methodist Church — 2.3 mi
• First Baptist Church of Kerrville — 2.3 mi