Hardest hit has been the northern city of Viseu. Countering fears that the insects are toxic invaders from Africa, entomologists have hastened to reassure residents that the species is harmless. A sudden heat wave on the heels of an unusually high rainfall caused this year's proliferation of the indigenous moths. But knowing the reasons for the infestation is little consolation. For months this city has been the central battlefield in an escalating German turf war fought by rival Vietnamese cigarette-smuggling gangs.
Many victims are onetime contract workers who stayed on after their visas expired.
Unable to work legally, they turned to selling smuggled cigarettes on the streets. Investigators have been hampered by language barriers and witnesses' fears of retribution. Last week, however, police arrested three Vietnamese and confiscated a small arsenal that included a pistol they believe was used to kill three cigarette vendors last month. By week's end, prosecutors had filed charges of weapons violations and were preparing murder charges against all three suspects. History's verdict on the U.N. is still in the jury box.