( CNN ) -- Liberia 's president has declared a state of emergency after hordes of ravenous caterpillars infested the country . The African armyworm caterpillar is chewing its way through Liberia 's food crops . Tens of millions of the worm-like larvae have appeared in the northern part of the country , where they are destroying green crops like cabbage and collard greens and contaminating the water supply , Liberian Information Minister Laurance Bropleh told CNN Wednesday from the capital of Monrovia . `` I am not aware that they have been here before , ever , and certainly not in this great number , '' Bropleh told CNN . `` That is why it was so overwhelming initially when we first discovered it . '' The state of emergency covers the three northern Liberian counties of Bong , Lofa , and Gbarpolu , Liberian officials said . President Ellen Johnson Sirleaf told legislators Monday that 350,000 people in 62 communities in those three counties may have been affected . There are also indications the bugs have spread to neighboring Guinea , Sierra Leone and Ivory Coast , Bropleh said . `` This is indeed a crisis , '' the president said Monday . Johnson Sirleaf said she appointed a task force , including members of the U.N. Food and Agriculture Organization ( FAO ) , to identify the species and commence spraying . Investigators suspect the caterpillars are African armyworms , the FAO said . The infestation is `` quite alarming , '' said Winfred Hammond , the FAO representative in Liberia . Hammond said the caterpillars started showing up sometime during the week of January 12 but spread quickly . In just a week , he said , the caterpillars had spread to 50 villages . The pests multiply rapidly and adult moths are able to fly long distances at night , the FAO said . Worsening the situation , the area 's water supply has been contaminated by the huge volume of feces dropped by the caterpillars , the FAO said . `` The plague is being described as Liberia 's worst in 30 years , '' the FAO said . `` The last African armyworm outbreak in the sub-region occurred in Ghana in 2006 . ''
Liberia declares emergency after reports of ravenous larvae infest Liberia . Tens of millions of the worm - like creatures have landed in northern areas . Up to 350,000 people in 62 communities may have been affected .