Objective To clarify the key biological characteristics of Ips hauseri, a major stem-boring pest in natural Picea schrenkiana forests, including its annual life cycle, generational development patterns, and overwintering habits in the Banfanggou area of Urumqi, thereby providing a scientific basis for the precise monitoring, early warning, and scientific control of this pest.

Method Field investigations were conducted from May to November 2025, with supplementary observations in April-May 2026, in the natural spruce forests of Banfanggou. The developmental process was systematically observed through periodic dissection of naturally infested trees in the field. Meanwhile, freshly cut healthy logs of P. schrenkiana were exposed in the field for natural colonization by adult bark beetles; their offspring were then used to inoculate additional logs (serial inoculation), and their development across successive generations was systematically monitored. During the overwintering period, samples were collected from tree trunks, lateral branches, and rhizosphere soil to determine overwintering life stages, sites, and spatial distribution of the pest.

Result Regular field dissection revealed that I. hauseri completed two generations per year in the study area. Observations on naturally colonized logs showed that the developmental duration for one generation was approximately 30 days; when the emerging offspring were used for further inoculation, the second generation likewise completed its development successfully. Overall, the life cycle in Banfanggou is bivoltine: overwintered adults begin flying in late April and attack in early May, the first-generation adults emerge in late June, and the second-generation adults appear in mid-August. Overwintering surveys indicated that the overwintering abundance in the soil (772.6 individuals per plant) was substantially higher than on the trunks (87.6 individuals per plant). All overwintering individuals in the soil were adults, while those on the trunks consisted of adults and a small proportion of pupae (21.9% of the trunk population).

Conclusion I. hauseri exhibits a bivoltine life cycle in the Banfanggou forests of the eastern Tianshan Mountains, with a predominantly soil-based overwintering habit. These results provide a crucial scientific basis for developing precise monitoring and management strategies for I. hauseri.