Impacts of transgenic Bt cotton on the stylet penetration behaviors of Bemisia tabaci biotype B: Evidence from laboratory experiments

Abstract

Stylet penetration behaviors of Bemisia tabaci biotype B on two transgenic cotton lines “GK12” and “GK19” expressing Bt toxic protein Cry1A (Bt cotton) and a non‐Bt conventional cotton line “Simian‐3” (CK cotton) were recorded with the direct current electrical penetration graph (DC‐EPG) technique. Our results suggested that EPG waveform patterns, types and characteristics [non‐probe (NP), pathway (C), potential drops (pd) and phloem phase (E(pd))] of Bemisia tabaci biotype B were very similar on the three cotton lines. There were no obvious differences of pathway variables among whiteflies on the three cotton lines. Some phloem variables related to E(pd)1 differed. Duration of 1st E(pd)1 and mean duration of E(pd)1 on both GK12 and GK19 were significantly shorter than that on CK cotton (P < 0.05). Fewer whiteflies on GK have long E(pd)1. Other phloem variables including total duration of E(pd) summed, mean E(pd) duration and percentage of whiteflies reaching the phloem phase were similar among the three cotton lines.

Waveform characterization of the soybean stem feeder Edessa meditabunda: overcoming the challenge of wiring pentatomids for EPG

“…The correlation between waveform Em3 and stylets in the phloem is supported by the following: (1) all histological sections showing stylet tips ending in phloem tissue during Em3; (2) negative voltage level (intracellular) inside living phloem sieve elements, as occurs in others insects, such as aphids (Prado & Tjallingii, 1994), psyllids (Bonani et al, 2010;Cen et al, 2012), and whiteflies (Jiang et al, 1999;Yin et al, 2010); and (3) the low relative amplitude of Em3, suggesting a smaller force to suck the sap of these tissues, that is, a passive ingestion (Backus et al, 2013). Smaller force is necessary because phloem sap is subjected to high internal hydrostatic pressure, which induces the exudation of phloem contents when it is damaged (Taiz & Zeiger, 2004).…”

“…This technique, known now as electrical penetration graph (Tjallingii, 1985), or electropenetrograph (both abbreviated EPG), allows observing and measuring of otherwise invisible stylet penetration/probing inside the opaque food. It was first used for aphids (McLean & Kinsey, 1964, 1965 and, later, for other sternorrhynchans, such as whiteflies (Janssen et al, 1989;Jiang et al, 2001;Yin et al, 2010), scales (Calatayud et al, 1994(Calatayud et al, , 2001, and psyllids (Bonani et al, 2010;Cen et al, 2012), and for auchenorrynchans, such as leafhoppers (Almeida & Backus, 2004;Jin et al, 2012). It was first used for aphids (McLean & Kinsey, 1964, 1965 and, later, for other sternorrhynchans, such as whiteflies (Janssen et al, 1989;Jiang et al, 2001;Yin et al, 2010), scales (Calatayud et al, 1994(Calatayud et al, , 2001, and psyllids (Bonani et al, 2010;Cen et al, 2012), and for auchenorrynchans, such as leafhoppers (Almeida & Backus, 2004;Jin et al, 2012).…”

“…EPG has become popular among researchers studying plantfeeding hemipterans. It was first used for aphids (McLean & Kinsey, 1964, 1965 and, later, for other sternorrhynchans, such as whiteflies (Janssen et al, 1989;Jiang et al, 2001;Yin et al, 2010), scales (Calatayud et al, 1994(Calatayud et al, , 2001, and psyllids (Bonani et al, 2010;Cen et al, 2012), and for auchenorrynchans, such as leafhoppers (Almeida & Backus, 2004;Jin et al, 2012).…”

An analysis of the feeding behavior of three stages ofToxoptera citricidabyDCelectrical penetration graph waveforms

“…Waveform ‘F’ is associated with stylet penetration difficulties (Tjallingii, , , ; Montllor & Tjallingii, ). At present, the EPG technique is a relatively precise and rigorous method used worldwide with aphids to investigate a range of topics including host specificity (Liu et al., ), resistance mechanisms of a host plant to insects (Marchetti et al., ; Yin et al., ), and virus transmission (Fereres & Collar, ; Boquel et al., ; Carmosousa et al., ), and as an important method for research on the physiology and biochemistry of piercing‐sucking insects (Backus et al., ).…”

Difference in Feeding Behaviors of Two Invasive Whiteflies on Host Plants with Different Suitability: Implication for Competitive Displacement

“…EPG has been used extensively in whitefly research 21-35, and EPG parameters including frequency, duration, and waveform sequence provide good indicators of host plant suitability 36. In this study, we used the EPG toolkit to look at elements from both the insect (feeding behavior) and plant (host suitability) perspective to better understand the factors involved in the competitive displacement of B. tabaci B by Q.…”