Yueguan Fu’s scientific contributions

The development, longevity and reproduction of Oligonychus biharensis on four different cultivars of litchi were studied in the laboratory. The total mortality rates from egg to adult on Feizixiao, Baitangying, Ziniangxi and Sanyuehong were respectively 37.27%, 32.45%, 25.52% and 17.32%. The developmental periods from egg to adult varied from 16.97 days on Sanyuehong to 21.05 days on Feizixiao. The average longevity of adult females ranged from 19.72 days on Sanyuehong to 27.01 days on Baitangying, while the oviposition of O. biharensis varied from 68.80 eggs on Baitnagying to 34.00 eggs on Sanyuehong. The daily ovipositon rate of O. biharensis varied from 5.29 eggs on Baitnagying to 1.76 eggs on Feizixiao. The net reproductive rate of increase ( R0), intrinsic rates of natural increase ( rm) and finite rate of increase ( λ) for O. bicharensis on Baitangying were the highest; the three life table parameters ( R0, rm and λ) of Oligonychus biharensis on Feizixiao were the lowest. According to the parameters mentioned above, Baitangying litchi was the most suitable host plant and Feizixiao was the most unsuitable host plant for O. biharensis in this study.

Observations on the development, survivorship and reproduction of Tetranychus piercei McGregor reared on fresh banana leaves were conducted at 16, 20, 24, 28, 32 and 36°C. The developmental time from egg to adult varied from 7.2 d at 32°C to 33.1 d at 16°C. The developmental threshold temperatures of egg, larva, protonymph, deutonymph, preoviposition and a whole generation were 11.2, 9.8, 11.9, 12.5, 13.3 and 10.7°C, respectively. The effective accumulated temperatures were 72.3, 33.6, 22.2, 27.8, 17.7 and 163.6 day-degrees, respectively. Within the range of 16 to 36°C, the relationships between developmental and survival rates of all immature stages, average number of eggs/female, longevity of adults and temperatures showed parabolic trends. Survival rate was the highest (96.1%) at 32°C; whereas at 36 and 16°C it decreased to 79.1 and 66.4%, respectively. The highest number of eggs (35.8 eggs/female) was recorded at 28°C; and the lowest at 16°C (17.9 eggs/female). Female longevity was the longest (34.5 d) at 20°C and the shortest (8.2 d) at 36°C. The net reproductive rate (R0) was the highest (23.6525) at 28°C and the lowest (5.1044) at 36°C. The intrinsic rate of increase (rm) and finite rate of increase (λ) reached maximal values (0.3488 and 1.4174 respectively) at 32°C, whereas minimal values (0.0724 and 1.0752 respectively) were at 16°C. The mean generation time and time for population doubling were the shortest at 36 and 32°C, respectively, which were 7.2192 d and 1.9871 d. The highest population trend index (25.28) was obtained at 28°C and the lowest (4.88) at 36°C. These population parameters and population trend indices increased with temperatures in a parabolic function. The results suggest that T. piercei could develop and reproduce within a wide range of temperatures, and that temperatures from 25.8-32°C are the most suitable conditions for the development, survival and reproduction of the mite.