Electrical Penetration Graph Recording (Whitefly)

Abstract

[Abstract] Electrical penetration graph (EPG) was first developed by Mclean and Kinsey (1964) and later modified by Tjallingii (1978 and 1985). The EPG system turns a phloem-sucking insects and its host plant into part of an electrical circuit that is completed when the insect's mouthparts penetrate the plant. The electrical signal is amplified by an amplifier and digitized by a converter. Fluctuations in voltage and electrical resistance are recorded and can be matched to specific feeding events. Current protocol is an efficient use of the EPG system to record whitefly feeding behavior on plants. Materials and Reagents 1. Plant (e.g., 2-3 true leaf stage) 2. Newly-emerged (e.g., 2-5 d old) female whiteflies Equipment 1. Ice-bag or box 2. Glass dish (Diameter = 6 cm) 3. Gold wire (Diameter = 12.5 μm, http://www.epgsystems.eu/products.php) 4. Silver glue (Vial of 2ml glue, http://www.epgsystems.eu/products.php) 5. Faraday cage (self-made cage with10 mesh wire net, length = 60 cm, width = 60 cm, height = 70 cm) 6. Insect-proof cage (self-made cage with 80 mesh nylon screening, length = 40 cm, width = 40 cm, height = 60 cm) 7. Transparent tubes (self-made tube with bottle, 3 cm long, inner diameter = 5 mm) 8. Small ice-chilled glass dish 9. Giga-8 DC-EPG system with 10 9 Ohm input resistance (Wageningen University, http://www.epgsystems.eu/products.php) 10. DI710-UL analogue-to-digital converter (DATAQ Instruments,