Influence of Human Disturbance to the Small Mammal Communities in the Forests

Small mammals have been proposed playing an important role in the energy flow and regeneration of forest ecosystems. We compared species richness, diversity (H’) of small mammal communities and abundance of six dominant species of small mammals in disturbed and protected forests (four age classes: 6 - 10, 11 - 15, 16 - 20 and 31 - 40 years old) in China. We also investigated the structural variables (such as species richness, cover rate and abundance of shrubs and grasses) in the bottom layer, which considered to be important for small mammals and might be altered by human disturbance. The relationships between small mammals and these structural variables were examined to determine the potential effects of human disturbance on the small mammals in the restored forests. Our results indicated that the structure and composition of the vegetation in the bottom layer were simplified by human disturbance, while the abundance and cover rate of grasses were significantly increased. Although no significant differences were observed in species richness of small mammals between the protected and disturbed forests at the same age, the diversity index of small mammals in the protected forests was always significantly higher than in the disturbed forests. Regression showed that the species richness and diversity of small mammals increased with the species richness of shrubs, and was negatively correlated to the cover rate of grasses in the bottom layer. Human disturbance increased the total abundance of small mammals, and the increased cover rate of grasses in the bottom layer was beneficial to the abundance of small mammals. Obvious succession of small mammal communities occurred as the protected forest aged. In the protected forests, small ground-dwelling mammals (A. chevrieri, E. miletus and M. pahari) were the dominant species in the younger forests. Other mammals (T. belangeri, D. pernyi and C. erythraeus) gradually became the dominant species as the protected forests aged. However, in the disturbed forests, the smaller ground-dwelling mammals (T. belangeri, D. pernyi and C. erythraeus) were always the dominant species at all ages of the disturbed forests. Regression indicated that the cover rate of grasses in the bottom layer was beneficial to the three smaller body size and ground-dwelling small mammal species, while the shrubs were beneficial to the three bigger body size mammal species.

Effects of Several Factors on Trapping Quantity of Grapholitha molesta Busck by Sex Pheromone

The key application technology for sex pheromone of Grapholitha molesta was studied from the aspects of different hanging heights and orientations, dif- ferent doses and types of traps through the tests on trapping quantity of G. molesta in fields. The results showed that the trapping effect was enhanced when the hanging height was increased, and the trapping effect was the best in west direction. The trapping effect was enhanced when the dosage was increased. When it was up to 6 lures, the trapping effect was the best with 38.75 head/trap; the next was 2 lures with 31.00 head/trap. All types of traps had trapping ability to G. mo- lesta, among which triangle trapper was the best, followed by self-made bottle trap. Their trapping effects were 138.75 and 100.25 head/trap, respectively.

Occurrence and Pollution-free Control of Apolygus lucorum in Winter Jujube

In recent years, Apolygus htcorum has become the main pest of winter jujube. It sucks juice of young parts of winter jujube and causes falling of buds and flowers, leaf perforations, deformities and fall- off of fruits, leading to serious economic loss. Considering the occurrence characteristics and control problems, the distribution, occurrence regularity, damage characteristics and outbreak reasons of A. lucorum are overviewed and analyzed in this paper, and the pollution-free control measures are also put forward.

Effects of Straw Returning and Chemical Control on Occurrence Quantity of Athetis lepigone Moschler in Summer Maize Fields

Athetis lepigone Moschler is a new kind of insect pest occurring in summer corn production areas. By investigation, it was found especially serious in straw returning fields. In this paper, its damage status was investigated in straw returning and chemical controlled fields, respectively. The results showed that the rate of damaged plants was 82% and the maximum pest number per 100 plants was 88 heads in the straw returning fields without chemical control. The application of herbicides and pesticides had no significant effects on occurrence quantity and damage rate, but the pest number per 100 plants decreased a little compared to the fields without chemical control. In the surer er maize fields without straw returning, the application of herbicides and pesticides could significantly decrease the damage of Athetis lepigone, the rate of damaged plants was 20%, and the pest number per 100 plants was 6.

Evaluation on Application and Spraying Effect of Air-Assisted Sprayer in Apple Orchard with Dwarfing Rootstocks

The application and spraying effect of 3 WG-1200 A air-assisted sprayer in dwarfing rootstock apple orchard were evaluated by investigating the droplet density, coverage and volume median diameter(VMD) in different canopy layers(2.0, 1.5, 1.0 m) and five directions(east, south, west, north and middle) of apple trees. The results showed that the droplet density was 166.99 per square centimeter, the coverage was 48.23%, and the VMD was 138.63 μm. The droplet density in different canopy layers of the trees had consistent trend with the coverage. The droplet density and coverage in the upper and middle canopy(2.0 m and 1.5 m) had no significant difference, but they were both higher than those in the lower canopy, while the VMD in different canopy layers showed an opposite trend. The change trends of the coverage and VMD in the five directions were consistent, and the values in the middle and east were the highest, followed by the north, south and west, respectively. The results indicated that droplet characteristics of the 3 WG-1200 A air-assisted sprayer met the basic requirements for pest and pathogen control. This study provides a theoretical basis and data support for the application and improvement of orchard application equipments in dwarfing rootstock apple orchard.

Landscape genetic analyses reveal host association of mitochondrial haplotypes in the Asian corn borer,Ostrinia furnacalis

Crop expansion often leads to high pest pressure.These pests may have fitness trade-offs related to host use,and some host-associated genotypes may benefit and increase in frequency.However,evidence concerning the effect of host availability on spatial distribution and frequency of mitochondrial haplotypes is scarce.We studied genetic variation of the Asian corn borer,Ostrinia furnacalis(Guenée),across a large area during 2 years(2016 and 2017).Mitochondrial sequence data were obtained from 530 individuals collected from 79 locations in Shandong Province,China.In total,155 haplotypes were found based on the combined cytochrome oxidase subunit 1(COI)and COII genes.Three haplotypes(H2,H12,and H23)were dominant,whereas most of the other haplotypes occurred in low frequency.A haplotype network showed that the 155 haplotypes can be grouped into three clusters.Haplotype clusters seemed to be randomly distributed.The frequency of H12(in Cluster 1)was positively correlated with maize crop proportion,but negatively correlated with other crops(primarily vegetables,oilseed crops,and cotton)at all spatial scales(1-,3-,and 5-km radius).Cluster 2 had haplotype H23,and this cluster was negatively correlated with semi-natural habitats.Cluster 3 had no dominant haplotype and was not affected by landscape factors.We conclude that H12 may be a maize-associated haplotype.Further study is needed to verify the possibility that the carriers of this haplotype may possess some fitness trade-offs.Our study highlights the importance of host availability in O.furnacalis haplotype distribution and frequency.