TitleBacterial leaf scorch Xylella fastidiosa wells et al. and its potential insect vectors in pin and red oaks in central New Jersey
NameZhang, Jianxin (author), Lashomb, James (chair), Hamilton, George (internal member), Kjer, Karl (internal member), Gould, Ann (outside member), Rutgers University, Graduate School - New Brunswick,
Bacterial diseases of plants--New Jersey,
Pin oak--Diseases and pests--New Jersey,
Red oak--Diseases and pests--New Jersey
DescriptionThe bacterium Xylella fastidiosa and its potential insect vectors were studied in central New Jersey. Eighteen X. fastidiosa isolates were obtained from symptomatic oaks; one isolate from the treehopper Ophiderma definita. The New Jersey X. fastidiosa strain shared high levels of nucleotide sequence identity (87-99%) with other known strains in the NCBI database. Phylogenetic analysis based on 16S-23S intergenic spacer region rRNA revealed that the New Jersey strain is X. fastidiosa subsp. multiplex closely related to isolates from oak, plum, porcelain berry, wild grape, peach, and sycamore.
Xylem feeding insects were monitored in oak canopies using yellow sticky traps and fogging techniques. Thirty-seven Cicadomorpha (Order Hemiptera) insect species were collected from oak canopies. Of the 12,880 xylophages collected, 91.40% were membracids, 6.93% were cicadellids, and 1.67% were spittlebugs. More insect species and individuals were collected using fogging compared to sticky card collections. Sticky card sampling in more locations over long periods provided similar insect species numbers as fogging. Ophiderma definita comprised 68.18% of the total insects collected and peaked in early June. Sticky card collections of O. definita were male biased when females were gravid. Ophiderma definita was more abundant in pin oaks than red oaks. The sharpshooter Graphocephala versuta comprised 6.2% of the total collection and peaked in mid-July. More xylophages were collected in the asymptomatic than in symptomatic oak canopies.
The X. fastidiosa DNA was detected in 21 xylophage species throughout the summer. The nucleotide sequences obtained from insects were identical to those obtained from host oaks. Fourteen percent (13.89%) of the 1618 insect specimens tested DNA positive for X. fastidiosa. Eleven percent (11.03%) of 934 membracids tested positive for X. fastidiosa: Enchenopa binota, Archasia belfragei, Cyrtolobus discoidalis, C. fenestratus, Glossonotus acuminatus, Microcentrus perditus, Ophiderma definita, Similia fasciata, Telamona extrema, T. monticola, and T. tiliae. Nineteen percent (18.79%) of 490 Cicadellidae insects tested DNA positive for X. fastidiosa: Aulacizes irrorata, G. versuta, G. coccinea, Draeculacephala anguifera, D. portola, and Oncometaopia orbona. Fifteen percent (15.08%) of 194 spittlebugs tested DNA positive for X. fastidiosa: Aphrophora quadrinotata, Clastoptera obtuse, Philaenus pallidus, and P. spumarius.
NoteIncludes bibliographical references (p. 132-139)
Noteby Jianxin Zhang
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
RightsThe author owns the copyright to this work.