D3212: Using a video tracking system to assess intraguild interaction between Anticarsia gemmatalis (Lepidoptera: Erebidae) and Chrysodeixis includens (Lepidoptera: Noctuidae) in soybean

Important soybean producing areas in USA and South American countries are threatened by lepidopteran pests, such as the velvetbean caterpillar, Anticarsia gemmatalis (Lepidoptera: Erebidae), and the soybean looper, Chrysodeixis includens (Lepidoptera: Noctuidae). In this sense, studying interactions between insects help to manage the crop production system. We aimed to examine potential differences in behavior between A. gemmatalis and C. includens in competition scenarios using an automated video tracking software (EthoVision), under laboratory conditions. The experiment was conducted at the University of Nebraska, Lincoln, NE, USA, using non-Bt soybean (Pioneer® P25A27X). Larvae interactions were assessed in scenarios with and without food. Measurements on each individual larva were taken for the distance moved (cm). When food was present, measurements on each individual larva were taken for frequency in food (n) and time in food (s). For scenarios where two larvae were present, measurements for the distance between larvae (cm) and body contact (s) was also recorded and analyzed. Distance moved, distance between larvae, body contact (food available) and frequency in food of C. includens larvae were negatively affected by interactions. Anticarsia gemmatalis larvae showed higher active behavior, moving twice or more the distance compared to C. includens larvae, and A. gemmatalis spent more time in body contact with food. Our results suggest that A. gemmatalis has a competitive advantage over C. includens. This study provides important information regarding lepidopteran interactions in soybean.