BOGOTA, Feb 9 (Reuters) - Colombia halted aerial spraying of chemicals on drug crops along its border with Ecuador on Friday after Quito renewed charges that the U.S.-backed anti-narcotics program was harming residents and farms. Tensions between the Andean neighbors heated up in December after Colombia restarted the spraying of herbicides it says are not only safe but vital to combating the coca leaf -- the raw material used to manufacture cocaine. Colombian President Alvaro Uribe, an ally to Washington, and Rafael Correa, his leftist counterpart in Ecuador, agreed in January to allow Ecuador to monitor spraying. But Ecuador still says it could sue Colombia, the world's top cocaine producer, over the use of the herbicides. "Colombia will now start manual eradication and end the fumigation phase so there should be good faith to put into action the agreement between the two presidents," Foreign Minister Maria Consuelo Araujo said in a statement. She said 1,200 workers would sweep southern Putumayo and Narino provinces, where leftist rebels and militias fight over rich coca leaf territory close to the border with Ecuador. Colombia has received around $4 billion in U.S. aid since 2000 to help fight the drug trade that fuels its four-decade internal conflict, Latin America's longest-running left-wing insurgency. Colombia says the U.S.-backed fumigation program is the only way it can counter coca production in remote areas where guerrillas are still fighting government forces. Correa, who echoes Venezuelan President Hugo Chavez's criticism of U.S. policies in the region, wants Colombia to halt all fumigation and conduct more studies on the effects of the herbicides used. Ecuador's government recalled its ambassador last year in protest over the spraying. Critics of the U.S. policy say coca leaf production is about the same as when Washington began its Plan Colombia program. The White House's anti-drug office said 144,000 hectares of coca were detected in 2005, enough to produce more than 500 tonnes of pure cocaine.
Gerardo arboleda, 75,, smokes a "Chamico" cigarette made by himself at the Vilcabamba valley in Ecuador's Andes mountains. in this photo taken March 4, 2007 These days, the famous elders of Vilcabamba are dying at a younger age, the result of the stresses of modern life brought by the scores of tourists and health buffs who flock here in search of eternal youth. Gangs of youths drinking beer and smoking around the village's main square contrasted sharply with the hardy elders carrying the day's harvest of potatoes, onions and herbs through the steep roads of the Ecuadorean Andes. Old timers say modern life has encroached on and disrupted the valley's tranquil and carefree lifestyle, which was key to their longevity. Centenarians used to be seen playing cards at the main square or sitting in church, villagers say, but there are fewer now as many have died in recent years. They cited recent funerals of two elders believed to be 118 and 124. To match Feature ECUADOR-CENTENARIANS/