CALIFORNIA | LOCAL
December 23, 1999
Butterfly populations in the Sacramento Valley and nearby foothills hit a 28-year low in 1999, according to UC Davis entomologist Arthur Shapiro. But the problem is not human intervention, he added. The villain was a freeze during Christmas week of 1998, which reduced the survival of overwintering eggs, caterpillars, pupae and adults, and a cool spring and summer, he said Tuesday. Of the region's 55 resident species, he said, 14 were largely or completely missing during his biweekly surveys.