Abstract: 【Aim】 The hawthorn spider mite, Tetranychus viennensis Zacher, is an important damaging pest on deciduous fruit trees in northern China. This study aims to explore the reproduction potential of male adults of T. viennensis. 【Methods】 Leaf disc bioassay was employed to investigate the number of matings in adult males, mating duration, the number of daughters fathered by a male and the percentage of males in offspring of T. viennensis under the laboratory conditions of 25±1℃, 60%±7% RH and a photoperiod of 16L∶8D. 【Results】 Upon emergence of T. viennensis adults, males continued to mate with females until the end of their life. The copulation duration of the first mating of males was the longest and became significantly shorter in following matings. The least copulation duration of a male to inseminate a female was 50 s, much shorter than in nature. The newly emerged male adults copulated and inseminated 26-37 females, and contributed to 688-989 daughters over their lifetime, depending on the sex ratio. The age (in days) of male adults significantly affected their mating capability. The daily number of matings of male adults significantly decreased when they were 5 dayold, whereas had no obvious change when they were within 3 day-old. However, the male adults were still able to inseminate several females per day when they were over 7 day-old. The mating history of male adults imposed significant effects on their mating capability. The daily number of matings of male adults significantly decreased when they historically mated more than 20 times, but male adults could maintain the capability to inseminate females sufficiently even they had inseminated 30 females. 【Conclusion】 Male adults of T. viennensis have an extraordinary reproduction potential to copulate, inseminate and fertilize female adults.

Key words: Tetranychus viennensis, reproduction, male adult, mating, insemination, female offspring