Zap! Electric Currents Measure Aphid Response to Bacterial Compounds
Mark Canlapan, Chloe Orth
Department of Biology
Faculty Supervisor: Mitzy Porras
The corn leaf aphid (Rhopalosiphum maidis) is an herbivore insect that feeds on corn (Zea mays). Farmers currently manage these pests using chemicals that cause environmental degradation as well as negative health effects for workers. It is known that the bacteria genus Pseudomonas has unique abilities to improve plant health. The strain Pseudomonas protegens PBL3 also secretes compounds that have known insecticidal effects against green peach aphids. The effect of this bacteria’s secretome on corn leaf aphids is unknown. In this project, we investigated whether the Pseudomonas protegens PBL3 secretome alters R. maidis foraging behavior. We monitored the aphids with an Electrical Penetration Graph, a method that uses electric currents to track aphid mouthpart insertion, salivation, and ingestion. Each trial recorded an aphid for 6 hours, on plants treated with either the bacterial secretome, or DI water. Our results show that about 57% of aphids feeding on plants treated with P. protegens PBL3 secretome fail to ingest the corn leaf’s phloem. This indicates that P. protegens PBL3 could serve as an ecologically healthy alternative to agricultural pesticides on corn plants.