Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 5/17/2011
Publication Date: 7/11/2011
Citation: Rangasamy, M., Backus, E.A., Stammm, M., Heng-Moss, T., Baxendale, F., Mcauslane, H. 2011. Waveform library for chinch bugs (Heteroptera: Blissidae): Characterization of EPG waveforms at multiple input impedances. Meeting Abstract. Available: http://www.infobibos.com/Hemipteran/CD/authors.html. Interpretive Summary:
Technical Abstract: Chinch bugs, Blissus spp. (Heteroptera: Blissidae), are among the most serious pests of grasses in North America. Southern chinch bug, B. insularis Barber, is the most economically important pest on St. Augustinegrass, the primary lawn grass in Florida. Western chinch bug, B. occiduus Barber, is a key pest on wheat and buffalograss, a common lawn grass in the western USA. Resistant grass and wheat cultivars have reduced chinch bug damage below economic thresholds for many years; however, resistance has often failed recently, and research efforts are underway to develop new grass cultivars resistant to these pests. Past studies have shown that chinch bugs are salivary sheath feeders that ingest primarily from phloem sieve elements. To support concurrent studies using electrical penetration graph (EPG) to compare chinch bug feeding among resistant and susceptible grass accessions, EPG waveforms were recorded for the first time for B. insularis and B. occiduus using the Backus and Bennett AC-DC EPG monitor. Waveforms were characterized for both AC and DC applied signals, using input impedances of 106, 107, 108, 109 and 1013 (“emf only”) Ohms. A matrix of waveform appearances (a “waveform library”) for both types of applied signal and all input impedances is provided. Electrical origin (R, emf or both components of the output signal), voltage levels, and repetition rates also are provided for waveform types described. For future studies, an input impedance of 107 Ohms, using either AC or DC applied signal, will provide the best balance of R and emf components. Although histological and biochemical correlations were not performed, biological meanings are hypothesized based on similarity in appearance waveforms recorded for other hemipteron species. Three putative pathway waveforms, two putative ingestion waveforms, and a hypothesized X-wave are characterized.