Table 1.
Summary of EPG AC–DC waveforms, their main characteristics and proposed biological meanings for each waveform recorded during feeding behavior of Euschistus heros on soybean pod (at R5 stage [pod filling])
| Phase | Family | Type or subtype | Amplitude (%) (range) | Frequency (Hz) (range) | Best seen at Ri levels | Electrical origin | Suggested biological meaning | ||
|---|---|---|---|---|---|---|---|---|---|
| Ri 107 | Ri 109 | Ri 107 | Ri 109 | ||||||
| Non-probing | - | Z | Flat | Flat | - | - | 106–109 | - | Standing still on the plant surface |
| Np | Low | Medium-high | - | - | 108–109 | Mostly emf; some R | Walking on the plant surface | ||
| Dw1 | 100% | 100% | Irregular | Irregular | 106–108 | Mostly R | Egestion of saliva/regurgitate liquid food on pod surface | ||
| Dw2 | 10% (6–13) | 36% (31–42) | 5.6 Hz (5.4–5.8) | 4.8 Hz (4.7–5.0) | 107–109 | emf-dominated | Probably re-ingestion of saliva/regurgitate liquid food | ||
| Pathway | P | Eh1a | 100% | 100% | Irregular | Irregular | 106–109 | R | Beginning of stylet penetration and secretion of gelling saliva to form salivary sheath |
| Eh1b | 62% (28–93) | 62% (46–91) | Irregular | Irregular | 106–109 | Mostly R | Deep stylet penetration and secretion of gelling saliva to form branches of a salivary sheath | ||
| Eh1c | 43% (28–61) | 35% (24–50) | 6.5 Hz (5.2–7.5) | 6.3 Hz (5.7–6.9) | 106–109 | R/emf | Bug encountering a rigid cell layer requiring stylet protraction and retraction | ||
| Eh1w | 65% (43–100) | 65% (43–97) | Irregular | Irregular | 106–109 | Mostly R | Stylets withdrawal from the plant tissue | ||
| Ingestion | I | Eh2 | 16% (7–31) | 33% (24–43) | 3.6 Hz (3.2–4.3) | 3.8 Hz (2.9–4.4) | 106–109 | Mixed; peak = R/emf; wave = mostly emf | Sustained xylem sap ingestion |
| Salivation | I | Eh3a | 21% (14–36) | 29% (16–47) | Mostly irregular + burst regular sections 3.9 Hz | Mostly irregular + burst regular sections 3.4 Hz | 106–109 | R/emf | Cell laceration and enzymatic maceration of endosperm tissue |
| Ingestion | I | Eh3b | 8.0% (3–13) | 14% (7–30) | 4.6 Hz (3.0–5.5) | 4.2 Hz (3.5–5.2) | 107–109 | Mostly emf | Short ingestion event of lacerated/ macerated endosperm tissue |
| I | Eh4 | 4.0% (2–6) | 8.0% (5–11) | 4.4 Hz (3.2–5.5) | 4.4 Hz (3.8–5.4) | Unknown | emf | Short ingestion event from an unknown site | |
| Interruption | N | Eh5 | 35% (16–70) | 29% (17–56) | Irregular | Irregular | 106–109 | R/emf | Short interruptions during xylem sap ingestion |