Preliminary Study on Spreading and Biological Characteristics of Crenidorsum turpiniae in Guizhou

The occurrence, spread, andbiological characteristics of the new record Crenidorsum turpiniae ontea bushes in Guizhou were studied. The dynamic movement, living habits, phototaxis,growth, and development of the pest insect were observed in the fieldand in laboratory. C. turpiniae was largely found in 12 counties(including districts and county-level cities) within the region. The localitieswith the highest incidences of infestation were Honghuagang, Meitan, and Yuqingin Zunyi City and Jinsha in Bijie City. The adult insects appeared in 4 peakperiods in a year with the largest population showing up during the firstperiod, which could reach a density of 1,828 adults per hundred leaves in asingle day. C. turpiniae matured into adults in the morning and preferredto rest on the abaxial side of upper tender leaves of a tea plant. They weremost active close to mid-day and less in the morning and evening and stronglyattracted to yellow light. The developments of the 1^st to the 4^th instar took 7.9 d, 4.3 d, 2.7 d, and 7.1 d, respectively, at 25℃.