It’s gut check time! A universal food immunomarking technique (UFIT) for studying arthropod feeding activities

Authors: Hagler, James

Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/13/2018
Publication Date: 1/22/2019
Publication URL: http://handle.nal.usda.gov/10113/6542279
Citation: Hagler, J.R. 2019. It’s gut check time! A universal food immunomarking technique (UFIT) for studying arthropod feeding activities. Annals of the Entomological Society of America. 112(3):211-219.

Interpretive Summary: The analysis of arthropod feeding activity is often determined by post-mortem predator gut content examinations. The conventional type gut assays are mono-specific assays that require time, resources, and technical expertise to develop to the food item (usually a pest insect species) that is the target of the investigation. A scientist at the ARS laboratory in Maricopa, Arizona pioneered an alternate method for gut analysis that does not require the development of a species-specific assay. This method (coined as the universal food immunomarking technique or UFIT) has been used to study a wide range of arthropod feeding activities such as, carnivory, herbivory, scavenging, etc. In this invited article, the ARS scientist reviews the UFIT procedure. The information provided will serve as the primary reference material for the next generation of scientists who study arthropod dispersal patterns.

Technical Abstract: The analysis of arthropod feeding activity is often determined by using species-specific post-mortem gut content polymerase chain reaction (PCR) and enzyme-linked immunosorbent assays (ELISA). Such mono-specific assays require time, resources, and technical expertise to develop to the food item (usually a pest insect species) that is the target of the investigation. A generic predator gut analysis method was described over a quarter of a century ago that does not require the development of a species-specific gut assay. This generic method remained in relative obscurity until about a decade ago. Recently it has been used to study a wide range of arthropod feeding activities such as, carnivory, herbivory, scavenging, etc. For this review, I have coined this method as the universal food immunomarking technique (UFIT). The UFIT consists of tagging food items (i.e., prey, foliage, carrion, etc.) with a specific protein. In turn, the gut contents of foraging arthropods are examined for the presence of protein-marked food items by a standardized protein-specific sandwich ELISA. In this article, I give examples of the benefits of the UFIT gut assay approach over prey-specific gut assay approaches, give tips on conducting a successful UFIT experiment, and provide examples of how it has been adapted to study a wide variety of arthropod feeding behaviors. My goal is to make researchers aware of another valuable tool in the gut analysis toolbox.