Objective To analyze the standby time of an intelligent rodent surveillance system and its influencing factors in Bayannur in western Inner Mongolia Autonomous Region (Inner Mongolia), China from September 2019 to December 2022, and to determine the correlation between rodent density and standby time. Methods Rodents were monitored using the intelligent internet of things terminal system VIMS 4.0. Statistical analysis was performed using Excel 2016 on the days of normal standby operation, number of rodents videoed, rodent density, standby time, and other indicators of the intelligent terminals, by different aspects (the first rodents of the same species, counties/banners, and different risk levels regions). Results A total of 231 rodents of eight species were detected by 10 effective terminal systems at three effective monitoring sites during the total effective monitoring time of 2 730 d. The top five most common species were Phodopus roborovskii, Meriones meridianus, Spermophilus alaschanicus, Cricetulus barabensis, and Mus musculus. The overall rodent density was 8.46%, and the mean activity frequency was 2.54 rodents/month·terminal system. The dominant species was P. roborovskii, which accounted for 57.58%. The standby time averaged 118.20 d, and ranged from 21 d to 329 d, mostly in 21-98 d, indicating a long standby time. The first rodents crossing the terminals involved four species. For terminals with the same species of the first rodents: in the descending order of rodent density, the top three species of the first rodents were Mu. musculus, S. alaschanicus, and Me. meridianus; in the ascending order of mean standby time, the top three species of the first rodents were Mu. musculus, S. alaschanicus, and Me. meridianus. The mean standby time of the terminals with the same species of the first rodents was moderately correlated with rodent density ( r=-0.634); the standby time was moderately correlated with rodent density in the area without definite risk levels ( r=-0.533). Conclusion This study first demonstrated a significant negative correlation between the mean standby time and rodent density in a certain space range and at a certain time scale.

Objective To test the effect of a contraceptive compound (levonorgestrel-quinestrol, designated EP-1) on reproduction in field populations of Maximowicz's vole (Microtus maximowiczii). Methods In 2004, a field trial was conducted in a guinea grass plot in Baiyinxile pasture, Xilingol league, Inner Mongolia, China. EP-1 was applied at the end of April and the reproductive parameters of field voles were inspected in May to July by monthly line transect census and track surveys. Data were analyzed by independent-samples t test. Results EP-1 strongly inhibited reproduction in female voles in the field. In the EP-1 baited area, the uterine damage rate in adult female voles was 78.9% while their pregnancy rate dropped to 0% in early June. In early July, uterine damage rate remained at a similar high level (76.7%) as that in June; the corresponding pregnancy rate and mean litter size both rose rapidly, but still differed from those in the untreated control area significantly (P<0.05). In early August, the uterine damage rate in female voles fell to 30.0%. Conclusion EP-1 is a safe contraceptive compound for the effective control of reproduction in field M. maximowiczii populations. Its inhibitory effect lasts three months before the vole's reproduction starts to recover.

Objective To test the effect of a contraceptive compound (levonorgestrel-quinestrol, designated EP-1) on reproduction in field populations of Maximowicz’s vole (Microtus maximowiczii). Methods In 2004, a field trial was conducted in a guinea grass plot in Baiyinxile pasture, Xilingol league, Inner Mongolia, China. EP-1 was applied at the end of April and the reproductive parameters of field voles were inspected in May to July by monthly line transect census and track surveys. Data were analyzed by independent-samples t test. Results EP-1 strongly inhibited reproduction in female voles in the field. In the EP-1 baited area, the uterine damage rate in adult female voles was 78.9% while their pregnancy rate dropped to 0% in early June. In early July, uterine damage rate remained at a similar high level (76.7%) as that in June; the corresponding pregnancy rate and mean litter size both rose rapidly, but still differed from those in the untreated control area significantly (P＜0.05). In early August, the uterine damage rate in female voles fell to 30.0%. Conclusion EP-1 is a safe contraceptive compound for the effective control of reproduction in field M. maximowiczii populations. Its inhibitory effect lasts three months before the vole’s reproduction starts to recover.

Objective Rodents can survive in any existing habitat, and are the largest order of mammals in terms of both variety and quantity of species. Unlike other mammals, their classification can be variable and complex, due to the large number of species. Furthermore, the inter-species characteristics and traits tend to be convergent. They pose a seriously increasing threat to agriculture. Hence it is crucial to find effective measures to manage and control rodent infestation, which requires confirmation of their taxonomic statuses precisely and quickly. However, an expert on one species or family may be unfamiliar with another. These issues have increased the demand for digitized software tools that can recognize and characterize rodent skulls from images. In this study we developed a system, named “Rodents Skull Automatic Identification System”, based on random forests. Methods The training module and recognition module of the system were designed based on the recognition technology of computer science, OpenCV, and random forests. The training module included image input, image preprocessing, feature extraction, pattern recognition, and identification result return. The recognition module included image input, image preprocessing, feature extraction, training classifier, and classifier data storage. The system identified rodents of 13 species from 4 families through automatic extraction and analysis of 32 mathematical morphological features on dorsal maxillary images, such as eccentricity and compactness. Results The system could identify 13 species among 4 families of rodents. The results showed that the average identification accuracy rate was above 80%, and the identification accuracy rate of each species was above 70%, indicating that the system was highly reliable in recognition of rodents. Conclusion Rodents can be automatically identified with the aid of computer technology. However, this system is only a preliminary study, and it requires further studies to improve the recognition rate.

Objective To investigate the major species of rodent pests in the livestock and poultry farms (pig farms, cattle farms, and chicken farms) in Beijing, China and the seasonal population variations in the rodent pests, and to provide a reference for rodent pest control. Methods The species and density of rodent pests were monitored monthly from August 2010 to July 2011 in 9 livestock and poultry farms in Fangshan district, Pinggu district, and Shunyi district, Beijing. In each farm, traps baited with peanuts were set to capture rodent pests at night. Results There were 21 600 trap-times throughout the year, and 236 rodents including Mus musculus and Rattus norvegicus were captured. The farms were affected by rodent pests more seriously in autumn (September to November) and winter (December to February) than in other seasons, and 54.4% and 31.6% of all rodent pests were captured in autumn and winter, respectively; the highest population density of rodents was seen in October. Throughout the year, there was alternate population variation between M. musculus and R. norvegicus; the sex ratios of M. musculus and R. norvegicus populations were 1.63 and 0.71, respectively. Conclusion Autumn (September to November) is the key period for rodent pest control in the livestock and poultry farms in Beijing.

【Abstract】 The rule of rodent control in village is parts of key technical standards regarding public health safety supported by the 11th five?year plan. To determine standard contents based on the reference of relevant standards at home and abroad, and to emphasize the rodent control technology in rural such as the put of baits, the establishment of prevention facilities and the elimination of rodent breeding sites. This article aims to discuss the writing significance, writing principle, working process as well as the problem in writing process.