Abstract:

[Objective] Shivaphis pteroceltis is a new pest on Pteroceltis tatarinowii, a member of the national grade Ⅲ rare and endangered tree species. The pests had the characteristics of rapid propagating, large quantity, strong outbreak, and long time damage, and cause serious damage to leaves, fruits and young branches of P. tatarinowii. Based on the study of the biological characteristics of S. pteroceltis, the ecological characteristics, such as the effective accumulated temperature, the influence of temperature on the size, population dynamics, and the phototaxis, were further studied in this paper, to lay a foundation for integrated control the pest. [Method] Five treatment temperatures were set to calculate the development threshold temperatures and effective accumulated temperatures by the linear regression method. Developmental duration of the insect under different temperatures was observed and recorded by rearing some wingless parthenogenetic aphids in culture dish in which the leaves of P. tatarinowii were placed, and the improved method of leaf discs was used to rear the aphids. The body length and body width of each aphid were observed, measured and recorded in different temperature gradients. SPSS was used to analyze the data of body length and body width to investigate whether there was a significant difference on aphid size between different temperature treatments. Population dynamics from the hatch of the winter egg of S. pteroceltis to the leaf blade was regularly observed, and then the population dynamics figure of S. pteroceltis and winged and wingless aphids quantity dynamic figure were drawn. According to the characteristics of aphid yellow taxis, the yellow boards were hanged at different heights in P. tatarinowii forest in study sites. The number of aphids was daily counted, and at last the data was collected and processed. [Result] The results showed: the developmental threshold temperature was (6.40±1.01)℃ and the effective cumulative temperature was 223.11 day degree±13.12 day degree, and the K'/K=15.89, indicating that there were 15-16 generations every year in Zaozhuang area. Within a certain range, with the increase of temperature, the development duration was shorter, and the size was smaller in the same age. There were three peaks of the aphid outburst, June 10th, July 30th and September 20th, in Zaozhuang City, Shandong Province. Population dynamics was sensitive to the environment factors such as wind and rain. The trapping effect of yellow sticky card was better in the lower canopy. [Conclusion] In the temperature range of 17-29℃, with the increasing of temperature, the developmental rate of aphid increased and the developmental duration decreased. The pest occurrence trend and the change law provide a theoretical basis for the prediction and comprehensive control. In order to reduce the manslaughter for natural enemy of the pests, such as ladybird, in actual production, the high-incidence season of the natural enemy should be avoided in trapping the pests.

Key words: Pteroceltis tatarinowii, Shivaphis pteroceltis, new pest, ecological traits