Nearly seven month after declaring a re - emergence of the New World screwworm fly in Costa Rica , a body politic of emergency was declared in the country on February 7 as the flesh - eating insect universe proceed to rise .
New World screwworm ( NWS ) flies ( Cochliomyia hominivorax ) , which are a species of blowfly ( family Calliphoridae ) , are native to much of North and South America and have been popping up andwreaking havocacross the continents for hundred . Having been known to carry off live - parentage populations , as well as infecting domestic pets and even humans , the tent flap lay its eggs inside the open wounds of any mammal ( and sometimes bird ) species . Once hatched , the larvae burrow deep inside the living tissue , make painful infection , tissue paper personnel casualty , and even decease .
Despite estimable elbow grease to keep the population under control in Costa Rica , the numbersreportedlycontinued to rise . As of March this year , the first case of human contagion wasreportedby the Ministry of Health and SENASA , marking the country ’s initiative case of human plague .
However , due to a decade - longeradication campaignby the US Department of Agriculture ( USDA ) which saw the first successful eradication of NWS in North America in the 1960s , it is hop that through flux government activity efforts they can once again " prevent , control , and eradicate " Costa Rica ’s NWS population .
What is a new world screwworm?
Screwworms , of which there are two species , are obligate parasites during their larval stagecoach . The New World screwworm , ortrue screwworm , is indigenous to much of North andSouth America . However , due to eradication crusade , they are before long found just in the northern countries of South America , northern Chile , and northern Argentina . However , import cases have beenobservedin Mexico , the US , and even the UK .
NWS aliveness cycles can fluctuate depending on temperatures , engage as farsighted as three months to discharge in colder clime , and as shortsighted as 18 daylight when the temperature averages 29 ° nose candy ( 84.2 ° F ) .
What makes the screwworm unusual and particularly dangerous is that , unlike most blowflies , screwworms prefer to lay their eggs on the wounds of living mammals as opposed to carrion . The screwworm fly front will seek out any wound or orifice and will lie down between 100 and 350 ballock around the boundary of the orifice .
In less than 24 hours , these eggs will hatch and burrow as a radical downwards into the wound . The plague spreads rapidly throughout groups of animals as the flavor from a larvae - infest combat injury is attractive to other egg - carry female , reap more screwworm flies to the orbit .
After about a week from hatching , the larvae , which have now grown from 2 millimeters ( 0.07 inch ) to 1.5 centimeters ( 0.6 inch ) , will stop feed and fall to the solid ground where they tunnel and pupate . They egress between seven and 60 days later , depending on the climate , to carry on the whole disgusting cycle again .
Screwworm plague are further complicated by the increase opportunity of unlike larval fell mintage entering the wound , increasing the hazard of contagion . If untreated , screwworm infestations can kill an animal within one to two weeks , with naval lesion plague in neonate being the deadliest .
Eradication strategy
Such an unusual specie requires some unusual tactics to keep the universe under dominance , and effort implement by the USDA have proved extremely successful .
Themethodfor eradication , called the unfertile insect technique ( SIT ) , image millions of intent male NWS desexualize using radiation . These Male are then dropped into the survive raging population , at a charge per unit of just about 3 million sterile tent flap twice a week in one affected Florida Keys orbit by the USDA during the eradication period . As distaff NWS mate once in their lifespan , mating with a unfertile male prevents the female from laying viable eggs .
First carried out in the US in1958due to plague eliminate live - stock populations in Florida , and the technique proved successful . It has afterwards been used often to tackle NWS outbreaks throughout the Americas and has helped tackle other invasive species too .
Scientists Dr Raymond Bushland and Dr Edward Knipling from the USDA were awardedthe 1992 World Food Prize for their employment developing the SIT , and it ’s hoped this originative method acting will once again release Costa Rica from the threats of NWS .
