Abstract
In tea fields, we estimated the day on which the number of adult tea spiny whiteflies (Aleurocanthus camelliae Kanmiya and Kasai) peaked using the effective cumulative temperature and compared it with the actual (observed) peak day, which was determined based on the number of adults captured by yellow sticky traps. We also estimated the number of generations produced each year in the tea fields. The days on which the number of adult tea spiny whiteflies peaked were estimated using the effective cumulative temperature, which was based on the temperature in each hour at Kikugawa-Makinohara point according to the Automated Meteorological Data Acquisition System (Japan) (AMeDAS). The peak days for each generation were compared in seven tea fields around the AMeDAS point in 2012 and 2013. As a result, it was found that the mean errors between the estimated and observed peak days of the first, second, and third generations were 4.4 (in 2012) and 4.7 days (in 2013), 4.3 and 4.9 days, and 6.6 and 4.0 days, respectively. These errors did not exceed 7 days, which was the trap exchange interval. The number of generations produced each year was estimated using the temperature data recorded at four AMeDAS points with different elevations. Our results suggested that in each year three generations were produced in Kawane-Honcho (290 m above sea level), four generations were produced in Omaezaki (45 m), and between three and four generations were produced in Kikugawa-Makinohara (191 m). Although the estimated peak day of the overwintering generation in 2013, which was forecast based on the observed peak day of the third generation in 2012, differed considerably from the observed peak day in Kikugawa-Makinohara, the peak day forecast from the peak day observed during the latter period of the second generation in 2012 was consistent with the observed peak day of the overwintering generation in 2013. These results suggest that in each year populations composed of three or four generations coexist in the tea fields in Makinohara district, which are located at 100–200 m above sea level.
