Biology, Ecology, Chemical Control Of Shivaphis Pteroceltis(Hemiptera:Aphididae), A New Pest Of Pteroceltis Tatarinowii

Pteroceltis tatarinowii Maxim is a species of the genus Pteroceltis endemic to China. And it has been listed as a member of the national grade Ⅲ rare plants. Shivaphis pteroceltis Jiang, An, Li&Qiao,2014is a new pest on P.tatarinowii, which has features of breeding and spreading fast, numerous and so on. This aphid is harmful to leaves, fruits and young branches of the hosts, and mainly affects the growth of trees and induces the sooty mould of Pteroceltis tatarinowii and the plants around them.By the investigation of forest and the indoor breeding, we study the distributions, damages, morphology, biology, ecology characteristics and have conducted the toxicity determination and the field efficacy trials. The results are as follows.1. The distribution, damage and the potential geographic distributionAccording to the survey, the S. pteroceltis has been discovered in Shandong, Anhui, Beijing and Shanxi Province, and the occurrence and damage is relatively serious in Zaozhuang Shandong Province, which damage rate highest up to100%. According to the distribution of S. pteroceltis was surveyed by the author, the potential distribution of it was predicted by Maxent niche model combined with environmental variables. The results show that most of potential high risk areas concentrate in Shandong province, few in Jiangsu province and Beijing; Potential middle risk areas are mostly distributed in Hebei, Henan, Anhui and Jiangsu Province; Potential low risk areas concentrate in Shanxi, Sichuan, Jiangxi, Liaoning, Hubei, Hunan and Zhejiang Province.2. Morphological characteristicsEggs first-timer to orange yellow, gradually become dark brown to black, after overwintering eggs for bright black, luster; Oval first instar, translucent, softness, bear no thick wax powder and wax filaments; Nymphs have four instars, the body bears thick wax powder and wax filaments; Adult aphid body oval, yellow green in life, bears thick wax powder and wax filaments. The adult fundatrix are wingless, and the body wider and shorter than alate viviparous females. Viviparous females contain both apterous and alate ones. Oviparous females are wingless and males are winged.3. Biology characteristicsThe present study found that it only infested P. tatarinowii. Its life cycle is monoecious holocyclic. Fundatrixs are hatched out in mid of March in Zaozhuang, the1st instar nymphs of fundatrigenia are laid in April and Viviparous females are produced in May. Whats more, the sexuales are produced in early October, and then the overwintering fertilized eggs are laid in mid-October.Viviparous females contain both apterous and alate ones. Apterous viviparous females have stronger hunger-resistance ability than alate ones.4. Ecological characteristicsThe developmental threshold temperature was6.40±1.01℃and the effective cumulative temperature was223.11±13.12day degree, through which we predicted there were15-16generation every year in Zaozhuang area. The leaf rate and population density in the canopy of different levels presented that the lower tree layer> middle> upper part in each layer of branches. The aphid had three peaks in Zaozhuang, on June10th, on July30th and on September20th, and winged aphid percentage significantly lower than the wingless aphid. There were three peaks of this aphid outburst, June10th, July30th and September20th, in Zaozhuang, Shandong province. The S. pteroceltis main natural enemies are Chrysopaperla, ladybird, hoverfly and spiders, etc, and the Chrysopa sinica Tjeder, Chrysopa septempunctata Wesmael, Harmonia axyridis Pallas, Epistrophe balteata DeGeer, Lycosa sinensis Schenkel are the dominant natural enemies. The S. pteroceltis are tropism of yellow, so the yellow sticky was hung on lower canopy to trap winged aphid, in oder to reduce the spread of pests.5. Chemical controlThrough the toxicity determination of the7pesticides against S. pteroceltis, results showed that Virulence from big to small in the order1.8%abamectin EC,0.5%matrine AS,4.5%beta-cypermethrin EC,0.3%azadirachtin EC,10%imidacloprid WP,1%celangulin EC and2.5%rotenone EC. And we chose5higher toxicity pesticides to conduct the field efficacy trials. The result showed that three kinds of the botanical pesticides1.8%abamectin EC,4.5%beta-cypermethrin EC, and10%imidacloprid WP had better field control efficacy on the Shivaphis pteroceltis after one day. But two kinds of botanical pesticide field control efficacy were slower, and their corrected mortality were more than90%after7days.