Has the indestructible insect met its match? Velvet ants as prey to bufonid toads

Abstract

Velvet ants are a group of parasitoid wasps that are well-known for a suite of defensive traits including bright coloration, a thick exoskeleton, and a painful sting. Previous experiments have demonstrated that while virtually all potential predators avoid velvet ants, toads (family Bufonidae) may be able to prey upon them. We conducted a series of trials to determine whether American (Anaxyrus americanus) and Fowler’s toads (Anaxyrus fowleri) prey upon velvet ants. Toad responses toward velvet ants were variable, ranging between complete avoidance, consumption and regurgitation, and consumption and retention. In total, 12 out of 22 trials resulted in the toads consuming a velvet ant. Of these, velvet ants were either regurgitated unharmed (n = 8) or retained (n = 4). In general, there were no significant differences in responses toward velvet ants between American and Fowler’s toads. Due to a rapid prey acquisition and their unique foraging behavior, toads present the most likely predator to velvet ants. Our results indicate that toads have the capacity to consume and retain female velvet ants. However, female velvet ants demonstrate the ability to endure upwards of 20 min inside the stomach of a toad and survive.

KEY WORDS:

• predation
• predator-prey
• anti-predator
• Mutillidae
• Bufonidae

ACKNOWLEDGEMENTS

Our deepest gratitude and appreciation go to Dr Walter Bruyninckx and Dr Anne-Marie Blancquaert for their careful observance and collection of velvet ants. Without their support, our research on predator–prey interactions involving velvet ants over the past 7 years would not have been possible. We also thank Coach Jim Watts and the Hanover Women’s Soccer Team for their assistance in the collection of specimens, and a special thank you to the many friends who were unwillingly dragged from their beds in the middle of the night for the sake of research.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

ETHICAL STANDARD

Toads were collected according to Indiana’s scientific purposes license (permit #19-335). General animal care protocols and limitations of the sample sizes in experiments using vertebrates are based on the “Guide for the Care and Use of Laboratory Animals” published by the National Research Council (2011).

DATA ACCESSIBILITY

All data is available upon request from corresponding author.

AUTHOR CONTRIBUTION

C.J. Mergler and B.G. Gall conceived and designed the experiment. Both authors collected animals and data. C.J. Mergler and B.G. Gall analyzed data. C.J. Mergler wrote the initial draft of the manuscript. Both authors edited and revised the manuscript.

Additional information

Funding

This research was funded by the Hanover College Department of Biology.