After a re - emergence trip anational emergencyin Costa Rica in February of last year , New World Screwworm ( NWS ) fly larvae ( Cochliomyia hominivorax ) have once again erect their tooth - extend heads , this time in southern Mexico – with the potential to foil the molding into the US .
Despite being regain in just one cow in southerly Mexico , near the border of Guatemala , its presence breaks a 34 - year - long point of obliteration for the country , a resurgence that ’s cogitate to have been spread through the illegal cows swop in Central and South America . Now , almost 60 years after its obliteration in the US , functionary warn the NWS could be on its way north of the border .
“ Illegal cows trade in Mesoamerica , the southern border of North America extending to the Pacific seashore of Central America , follow transboundary itinerary starting in Nicaragua and passing through Honduras and Guatemala , before infiltrating Mexico ’s intellectual nourishment supplying chain and reaching as far as the US , ” Jeremy Radachowsky , Wildlife Conservation Society ’s Regional Director for Mesoamerica , said in astatement .
“ This unregulated cross - border movement has created a rapid corridor for the parasite , take into account it to travel nigh 700 statute mile [ 1,126 kilometre ] – from the Nicaragua - Honduras border to Catazajá , Mexico – in just two and a half month . ”
Texas Parks and Wildlife Department ( TPWD ) has issued astatementwarning residents of Southern Texas to be particularly vigilant for sign of NWS infection and to account any potential pillowcase .
Clinical signs of NWS infection may include :
What is a new world screwworm?
Screwworms , of which there are two coinage , are obligate sponger during their larval stages . The New World screwworm , ortrue screwworm , is indigenous to much of North andSouth America .
What make the screwworm unusual and particularly serious is that , unlike most blowflies , screwworms prefer to lay their egg on the wound of hold out mammals as oppose to carrion . The screwworm fly will search out any injury or orifice and will place between 100 and 350 eggs around the edge of the hatchway .
In less than 24 60 minutes , these eggs will hatch and burrow as a group downwards into the wound . The plague spreads quickly throughout group of animate being as the smelling from a larvae - infested wound is attractive to other orchis - carry females , drawing more screwworm flies to the arena .
After about a week from hatch , the larva , which have now grow from 2 mm ( 0.07 column inch ) to 1.5 cm ( 0.6 inch ) , will kibosh feeding and fall to the ground where they burrow and pupate . They emerge between seven and 60 days by and by , bet on the climate , to continue the cycle again .
Screwworm infestations are further rarify by the increase probability of unlike larval fly species enter the lesion , increase the chances of contagion . If untreated , screwworm infestations can kill an animal within one to two hebdomad , with naval wound plague in newborn baby being the deadly .
Eradication strategy
Such an unusual mintage require some unusual maneuver to keep the population under control , and crusade apply by the US Department of Agriculture ( USDA ) have prove super successful .
Themethodfor eradication , called the aseptic worm technique ( SIT ) , sees millions of captive male NWS sterilized using radiation . These males are then dropped into the existing uncivilised population , at a pace of around 3 million aseptic fly ball doubly a workweek in one affected Florida Keys region by the USDA during the eradication period . As distaff NWS mate once in their lifespan , mating with a sterile male person prevents the female from laying feasible testis .
First pack out in the US in1958due to infestations eradicate live - stock population in Florida , the technique prove successful . It has afterwards been used often to take on NWS outbreaks throughout the Americas and has helped tackle other encroaching specie too .
Now , the Panama - United States Commission for the Eradication and Prevention of the Cattle Screwworm ( COPEG ) continues its study to monitor and maintain the Permanent Prevention Biological Barrier to keep NWS population under control .
Until the scourge in Mexico and bordering US states diminishes , however , official warn residents to wear louse repellant and handle heart-to-heart injury when outside .
