Marking Helicoverpa zea (Lepidoptera: Noctuidae) with fluorophores for use in mark-release-recapture research

Authors: Hagler, James; Casey, Miles; Machtley, Scott; SCHUTZE, INANA - Non ARS Employee; Fabrick, Jeffrey

Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/12/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Tracking insect movement is essential for efficient pest management. A new method for distinctly marking insects was recently described for tracking them in their habitat. The mark consists of a green-colored glow-in-the-dark liquid (fluorophore). Scientists at the ARS laboratory in Maricopa, Arizona, examined the efficiency of the fluorophore mark on corn earworm, a significant economic pest on various crops, including cotton and corn. The scientists proved that adult moths could be marked directly by topical application or indirectly by submerging the pupal stage in the marking solution. The mark was easily detectable throughout their entire adult lifespan. The study also determined that the mark did not have any adverse effects on the moth’s lifespan and flight behavior. The results show that the mark could be a practical marker for corn earworms and other species targeted for large-scale dispersal research, such as sterile insect release and augmentative biological control programs.

Technical Abstract: Knowledge of insect dispersal and long-distance migratory flight capacity and patterns represent key factors needed for risk assessment of invasive pest species, insecticide resistance management, and more effective pest management. Having operative tools to both mark and track insect pest movement is therefore critical to achieving such goals. Here, we describe a new procedure for marking Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), one of the most economically important crop pests in the United States. Adult H. zea moths were effectively marked using the liquid fluorophore cartax green, a persistent UV-fluorescent pigment, both directly by topical application and indirectly by briefly submerging pupae in the marking solution prior to adult emergence. Regardless of the application method, the cartax mark was retained on the moths throughout their entire adult lifespan. No mortality differences were observed between cartax green-marked and water-marked (control) moths. Additionally, using rotary flight mills, we found no significant differences in several flight parameters, including total number of flights, flight speeds, flight distances, or flight durations between unmarked and cartax-marked moths. Under laboratory conditions, we did observe the lateral transfer of different colored fluorophores between moths, indicating that undesirable marking could potentially occur. Moreover, we found that not all fluorophores were equally retained on H. zea moths, with cartax green remaining intact on moths longer than did a corresponding magenta fluorophore. The results show that cartax green fluorophore could be a practical marker for H. zea and other holometabolous species targeted for large-scale mark-release-recapture research.