Experts warn of larger than average numbers of alfalfa caterpillars in east Weld County
September 2, 2017
Experts are warning alfalfa growers in the Wiggins and Weldona areas to beware of higher-than-average numbers of alfalfa caterpillars this month.
According to a news release from William Trujillo of the Logan and Morgan extension office of Colorado State University, farmers in the area have reported an increased rate of the pests. The butterflies of the caterpillars typically in August lay eggs on new alfalfa, which is less than 6 inches tall. Within five to seven days, according to the release, the eggs hatch and caterpillars emerge, which are typically 1.5 inches long and velvety green with a white stripe down their side.
Caterpillars consume alfalfa leaves whole, and are more likely to prey on freshly planted crops. Hot, dry weather and slow growth of the crop have likely contributed to the increased number of caterpillars, the release states.
Any pyrethroid insecticide should be effective against the caterpillars, according to the release. The release also states if the crop is due to be cut soon, it may be best to hold off treatment until after harvest and then assess the damage the pests may have caused.
Those interested in more information about chemical control can visit the High Plains Integrated Pest Management Guide at wiki.bugwood.org.