Species and population dynamics of cultural relics pests
Before the trapping, investigate the pest hazards in Hall of Mental Cultivation, record the degree of pest damage to cultural relics, and grasp the species of pests and their active areas. The previous investigation showed that the distribution of pests was uneven, as showed in Fig. 3a. As a whole, the damage to the west of the central axis was heavy, while the east side was relatively intact. Based on the damage of on-site woolen fabrics, silk fabrics, paper relics, and timber structures, it was presumed that the species of pests should be carpet beetle, silverfish, clothes moth, bark beetle, and powder post beetle. Based on this, trapping investigation plan was formulated, Fig. 2.
After fumigation, pheromone traps were utilized to monitor the pests. Monitoring began in July 2017 and completed in December 2019. The monitoring area included the main hall and the eastern and western side halls. Enclosure room and duty room are set as a buffer zone, Fig. 3b.
So far, our investigation results showed that after fumigation, pests can also appear slowly, even in the presence of buffer zones. There were more than ten species of insects, such as carpet beetle, booklice, silverfish, ground beetle, woodlice, scutiger, spider, spider beetle, Katydids, powder post beetles and clothes moths, among which the cultural relics pests were carpet beetle, booklice, silverfishes, spider beetle, powder post beetle and clothes moth. The rests were live herbivores or small carnivorous insects that do not directly harm cultural relics. However, the presence of their carcass will attract the carpet beetles to eat, increasing the security risk of cultural relics. Among the cultural pests, the quantity of carpet beetle was the highest, with a total of more than 1,300 in two and a half years, followed by the booklice, two of them make up 79% of the total. Silverfish, powder post beetle, spider beetle clothes moth appear infrequently, the quantity was still less than 10, as showed in Fig. 4.
The captured carpet beetles were mainly larvae, and adult seldom appears. Accordingly, this phenomenon suggest the potential that the pheromone of carpet beetles should be aggregate pheromone. Compared with the sex pheromone that only affects single sex and sexually mature individuals, the aggregate pheromone is secreted by some insects and acts to gather the different individuals for food and labor. The trapping number is more and it can be a better protection of cultural relics.
The distribution of pests was extremely uneven, the number of buddha room was the largest, and the number of carpet beetles accounted for a large proportion, more than 1000, while the remaining 300 carpet beetles were mainly distributed in the west warm pavilion, the main hall and the east warm chamber. The second was the central bay, the number of carpet beetle and booklice was at most. In the western side hall, the number of woodlice and ground beetle was more, while the proportion of woodlice in the western side hall is larger. There were many species of insects in the back hall, the Hall of Swallows Happiness and the Hall of Manifesting Obedience, but the quantity is small.
There were two species of carpet beetle that been trapped,the first is Anthrenus picturatus hintoni Mroczkowski, which can be found in most provinces of China and mainly damages woolens, feather products, animal materials and specimens. The old mature larvae overwinter and the adults fed on pollen nectar, Fig. 5a. The second, Thylodrias contractus Motschulsky, is distributed in most provinces of China. The larvae can damage a variety of animal products and animal specimens, as shown in Fig. 5e.
The trapped booklice was Loposcelis bostrychophila,which is widely present in many kinds of storage. This booklice is extremely small and can reproduce at an amazing rate, making it difficult to eliminate༌so it can destroy furnitures, clothes and books on a large scale. So༌booklice should be killed in time if finding, Fig. 5b.
Lyctus brunneus Stephens is one kind of powder post beetle,that widely distributed in China. It feeds on dry, high-starch wood, furniture, bamboo and traditional Chinese medicinal herb etc. Both adults and larvae live in wood༌but adults need to leave the wood when they mate, so we can capture it. Figure 5c.
Tinea pellionella mainly distributed in central China and Beijing, Tibet and other places. It damages textiles and causes regular holes. It also damages articles containing keratin such as rabbit hair, wool and chicken hair, as showed in Fig. 5e.
Two species of spider beetles were caught in the investigation, one was Gibbium aequinoctiale Boieldieu,Fig. 5f༌the other was Ptinus japonicus Reitter༌Figure 5 g. Both of them are distributed in most provinces of China, feeds on dried or rotting animal and plant materials, including flour, grain, seeds, fur, wool, Chinese medicinal herbs and animal specimens.
There is a wide food range of Ctenolepisma villosa, including grains rich in protein, sugar and trace elements, Chinese medicinal herbs, photos, paper, paste, cotton, animal fur, silk fibers, and even organic matter in indoor dust. It like dark and humid environment, mostly hidden in the gap of the host during the day, and comes out at night to forage, Fig. 5h.