myiasis, is a disease of domestic animals, the 

 Animal Disease Eradication Division was as- 

 signed the responsibility of effectuatinK a pro- 

 gram to eradicate this insect pest from the 

 Southeastern United States. 



Screwworm flies: Left, male; riyhl, female. 



Early investigations 



Screwworms have been known in Texas since 

 1842. During the summer months infe.stations 

 spread to adjoining States but subsequent cold, 

 winter weather usually killed all but those in 

 southern Texas. Screwworms were unknown 

 in the Southeast until the summer of 19:):>, 

 when the first infestations were reported in the 



Larvae of screwworm. 



vicinity of Boston, Ga. They .spread rapidly 

 and within 2 years were found throughout 

 Florida. Each summer, infestations spread 

 into Georgia, Alabama, and occasionally far- 

 ther north, but they were subsequently killed 

 by cold, winter weather in all Southeastern 

 areas except peninsular Florida. 



Heavy losses sustained by the livestock in- 

 dustry of the Southeast due to screwworm at- 



BN-4376 



BN-4380 



Eggs of screwworm. 



Pupae of screw^vorm. 



15 



