title: Isolation and characterization of Aschersonia placenta from citrus orchards and its pathogenicity towards Dialeurodes citri (Ashmead).
abstract: For selecting potential biological agents to control Dialeurodes citri, a major insect pest in China's citrus orchards, 75 native Aschersonia isolates were selected from infected whiteflies in citrus orchards and were evaluated for virulence to third instar nymphs of D. citri at a concentration of 1 × 10(6)conidia/ml. The mortality rates of D. citri varied from 0% to 72.70%. Among the 75 Aschersonia isolates, three (HB10, HB12 and ZJ9) were the most virulent and pathogenic to D. citri and caused more than 69% mortality. The 50% lethal concentration (LC(50)) values of them were 1.86 × 10(6), 3.40 × 10(6) and 6.81 × 10(6)conidia/ml, respectively. The three isolates also produced conidia abundantly on potato dextrose agar medium (3.95 × 10(6), 6.19 × 10(6) and 7.34 × 10(6)conidia/cm(2), respectively). They were identified to be Aschersonia placenta based on their morphological analysis. Phylogenetic analysis showed that these three highly virulent Aschersonia isolates belong to a strongly supported clade that includes two other A. placenta isolates obtained from Vietnam and Thailand. In summary, these results indicate the possibility of developing the three most virulent A. placenta isolates as microbiological control agents against citrus whitefly.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Institute of Urban and Horticultural Pests, and Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Pingping
authors.initials: P
authors.lastname: Wang
authors.forename: Xuhong
authors.initials: X
authors.lastname: Song
authors.forename: Hongyu
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002957:Citrus / Q000382:microbiology; D006430:Hemiptera / Q000382:microbiology* / Q000502:physiology; D054884:Host-Pathogen Interactions; D006999:Hypocreales / Q000302:isolation & purification* / Q000472:pathogenicity* / Q000502:physiology; D008136:Longevity; D008954:Models, Biological; D010572:Pest Control, Biological / Q000379:methods*; D014774:Virulence