Evaluation of Phototactic Behavior by Two-dimensional Open Field Test in the Brown-Winged Green Bug, Plautia stali (Scott) (Hemiptera: Pentatomidae)

Open field test (OFT) is a widely used procedure for the analysis of animal behaviors. However, a few studies using this method have been reported in insects. We here attempted to analyze a phototactic behavior of the brown-winged green bug, Plautia stali (Scott) by OFT, and to evaluate the effectiveness and utility of this approach. Bugs were released at the center of open field arena then illuminated with a light emission diode (LED). Their phototactic behavior was recorded by an infrared camera then two-dimensional trajectory analysis was performed for the video sequences. As a result, the OFT characterized an orientation pattern and walking speed of bugs approaching a light. We conclude that the OFT is an advantageous approach for the close examination of phototactic process and considering the ecological significances in insects.