U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.


Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Main content area

It’s Gut Check Time! A Universal Food Immunomarking Technique for Studying Arthropod Feeding Activities

James R Hagler
Annals of the Entomological Society of America 2019 v.112 no.3 pp. 211-219
arthropods, carnivores, dead animals, digestive system, enzyme-linked immunosorbent assay, foraging, herbivores, insect pests, leaves, polymerase chain reaction, predators, protein tagging
The analysis of arthropod feeding activity is often determined by using species-specific postmortem gut content polymerase chain reaction and enzyme-linked immunosorbent assays (ELISA). Such mono-specific assays require time, resources, and technical expertise to develop for 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, and other feeding interactions. 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 and 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.