Thesis
Characterization and correlation of electrical penetration graph (EPG) waveforms of the psyllid Bactericera cockerelli (Hemiptera: Triozidae)
Washington State University
Master of Science (MS), Washington State University
2013
Handle:
https://hdl.handle.net/2376/102205
Abstract
Potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae), is the vector of "Candidatus Liberibacter solanacearum" (Lso) (also known as "Ca. Liberibacter psyllaurous"), a phloem-limited bacterium and the causal agent of "Zebra Chip" (ZC), an emerging and economically important disease of potato (Solanum tuberosum L.) in many parts of the world. Despite the importance of B. cockerelli as a vector of Lso in potato and other solanaceous crops, little is known about the psyllid stylet probing behaviors that control transmission of Lso. Herein, I report the first study identifying and characterizing the electrical penetration graph (EPG) waveforms representing stylet penetration behaviors of the potato psyllid feeding on potato. Waveforms produced by adult B. cockerrelli on potato were also defined (correlated) using light microscopy of salivary sheath termini in plant tissue after probes were artificially terminated during the identified waveforms. In addition, behavioral activities were also inferred based on waveform similarities in relation to other Sternorrhyncha, particularly aphids and whiteflies. Adult B. cockerelli produced six distinctive waveform types: C, waveform probably v representing secretion of the salivary sheath and intercellular stylet pathway in epidermis and parenchyma; D, waveform associated with the initial contact of phloem cells; E1, waveform associated with putative phloem salivation; E2, waveform representing phloem sap ingestion; and G, waveform associated with xylem ingestion. In addition, a previously unreported waveform type associated with xylem was discovered and designated H. Active phloem sap ingestion during E2 may play a critical role in acquisition of Lso bacterial cells, because the bacterium is a phloem-limited pathogen. Salivary gland secretion behavior associated with E1 may be most important for inoculation of Lso into phloem sieve elements . Measurement of EPG waveforms of B. cockerelli could assist plant breeding programs by enabling faster identification of potato cultivars resistant to psyllid feeding and disease transmission. These waveforms also have the potential to strengthen integrated pest management strategies by incorporating alternative plant hosts and maximizing the efficiency of pesticides.
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Details
- Title
- Characterization and correlation of electrical penetration graph (EPG) waveforms of the psyllid Bactericera cockerelli (Hemiptera: Triozidae)
- Creators
- Cole Christopher Pearson
- Contributors
- Allan S. Felsot (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Entomology, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525008501842
- Language
- English
- Resource Type
- Thesis