Evaluation and Efficacy of Oral Biomarkers for Lygus Lineolaris1

Authors: Glover, James; Parys, Katherine; George, Justin; Little, Nathan; Portilla, Maribel

Submitted to: Southwestern Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/14/2024
Publication Date: 7/1/2024
Citation: Glover, J.P., Parys, K.A., George, J., Little, N., Portilla, M. 2024. Evaluation and Efficacy of Oral Biomarkers for Lygus Lineolaris1. Southwestern Entomologist. 49(2):713-732. https://doi.org/10.3958/059.049.0216.
DOI: https://doi.org/10.3958/059.049.0216

Interpretive Summary: The tarnished plant bug is a serious insect pest of fruits, veggies, and other important agricultural crops like cotton across the United States. Tarnished plant bugs utilize and inhabit many different wild and weedy host plants in addition to agronomically important plants throughout the year. Movement between these plants throughout the year is poorly understood, and in need of further examination to better manage populations across the landscape. In this study we tested the potential use of eight oral biomarkers or dyes using a portable fluorescent light and filters to track L. lineolaris movement. Insects were fed honey water solutions of Safranin O, Acridine Orange, Rhodamine B., Fluorescein sodium salt, Acid Fuchsin, Brilliant Blue, Fluorescent Brightener 28, Carmoisine dyes using three methods; dye infused floral foam, dye overlaid a solid diet, and dye incorporated into a semisolid diet. At 24, 48, and 72 hour intervals, immatures and adults were removed from each treatment, were killed by freezing and evaluated for florescence. Results from this study indicate that Safranin O, Rhodamine B, and Acridine Orange are potentially useful as orally ingested biomarkers for both immature and adult tarnished plant bug. The findings from this study will help answer important ecological questions about movement and dispersal across agricultural landscapes.

Technical Abstract: The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae) is a highly polyphagous insect pest feeding on many wild hosts and cultivated crops of economic importance. Landscape composition plays an important role on tarnished plant bug population dynamics, and in need of further examination to better manage populations across the agroecosystem. In this study we evaluated the potential of eight oral biomarkers in combination with an inexpensive and portable fluorescent adapter for tracking L. lineolaris movement. Tarnished plant bugs from a laboratory colony were exposed to a 10% honey water solution used to make stock solutions of 1 g/L of Safranin O, Acridine Orange, Rhodamine B., Fluorescein sodium salt, Acid Fuchsin, Brilliant Blue, Fluorescent Brightener 28, Carmoisine dyes and a dye free control consisting of water using three ingestion methods; dye infused floral foam, dye overlaid diet, dye incorporated diet. At 24, 48, and 72 h intervals, L. lineolaris nymphs and adults were removed from each treatment, were killed by freezing and evaluated for florescence using a microscope equipped with a NightSea™ Florescence adapter under different lighting and filter combinations. Results indicate that Safranin O, Rhodamine B, and Acridine Orange are potentially useful as oral biomarkers for both nymph and adult L. Lineolaris when incorporated into a honey water solution and delivered via floral foam, diet overlay, or diet incorporated ingestion. This study may help insect pest managers to select dye agents for specific life stages to address different mobile phases of an insect life cycle.