Workshop shares use of technology to assess bed bug feeding

To understand food preferences and the damage that pests cause within plants, Embrapa Trigo carried out in-depth studies using EPG – Electrical Penetration Graphic, equipment that allows monitoring the feeding behavior of sucking insects. To share the knowledge acquired over the last five years, a Workshop on the use of EPG on bedbug pests in the laboratory was structured. The Workshop will bring together 15 professionals from Brazil, England and Uruguay, from April 01st to 04th, at Embrapa Trigo (Passo Fundo, RS).

The EPG equipment consists of sensors, attached to insects and food, which capture the process and record the information on a computer. A gold thread is attached to the insect with silver glue, transferring information in the form of waves that are interpreted with the help of software. When the insect penetrates the plant, an electrical circuit is generated, where a low intensity current circulates through the system. The energy passes through the host plant, through the insect and returns to the monitor in the form of signals that record waves on a graph. This way, it is possible to interpret how the insects are feeding, where they are on the plant, how much food is extracted, what the times are and the type of damage. Visually, the result is similar to an electrocardiogram, a common test in humans, where sensors record the intensity of the heartbeat in the form of waves. 

In the main research centers in the world, where there is work with pests in the laboratory, EPG is mainly used to monitor the feeding activity of aphids (popularly known as aphids). According to Embrapa Trigo researcher Antônio Panizzi, the challenge for researchers here was to use the technology on bedbugs, since the greater movement during the feeding process made it difficult for electronic materials to adhere to the insect's body: “we had to test numerous ways of doing this. the so-called 'ramification' of bedbugs to connect them to EPG equipment. The result was achieved by sanding the surface of the insect with dental sandpaper to connect the gold wire, which, in addition to being flexible, allows the transmission of current, and the silver glue, which keeps the filament attached to the insect.”

Bedbugs

Several species of stink bugs occur in wheat, soybean and corn crops and are considered insect pests of high economic importance. At Embrapa Trigo, five species of stink bug pests have already had their feeding behavior determined using the EPG technique. Using EPG, it was possible to record specific feeding sites in different plant structures. According to post-doctoral student Tiago Lucini, this type of result could help with pest control strategies, as through biotechnology techniques, genes that control the production of toxins could be expressed in the places on the plant where stink bugs feed. . At Embrapa Trigo, studies support plant improvement, selecting lines that are more resistant to pests. Furthermore, EPG has been applied to study the behavior of new insecticide molecules in evaluating their effectiveness in controlling pests and studying the mechanisms of virus transmission.

Workshop 

The Workshop on the use of EPG in bedbugs in the laboratory will feature 32 hours of theory and practice, involving the handling of equipment and reagents. With the guidance of specialized instructors, participants must apply knowledge in specific procedures for monitoring the bedbug feeding process, including preparing the bedbugs for use in the EPG, branching methodology (connection with the gold thread to the insect and equipment), handling the device with familiarization with the adjustments of the various controls, and preparing material for histological studies. The vacancies available in this first Workshop have been filled and registrations are closed.