Biology and ecology of a deep cave nesting spider wasp, Ageniella evansi Townes, (Hymenoptera: Pompilidae), in Arizona

ABSTRACT

Cavernicolous populations of the spider wasp Ageniella evansi Townes, 1957 (Hymenoptera: Pompilidae) nest deep within limestone caves at Colossal Cave Mountain Park near Tucson, Arizona, USA. These remarkable populations are the only truly cavernicolous pompilid wasps currently known. As many as 79 females were documented nesting simultaneously within Arkenstone Cave. The facts that the wasps do not nest near cave entrances but only deep within the interior of the caves, are philopatric to each occupied cave and have been present each year for decades confirm their cavernicolous behaviour as subtroglophiles. Studies conducted for over 30 years revealed many insights into the behaviour of these wasps in addition to their nesting deep within limestone caves, including: intraspecific and interspecific competition, plasticity in host selection, precision solar navigation, evidence that some form of communal nesting may be present and behaviour suggestive of rudimentary cognition in the species. This study demonstrates the importance of assessing all animals found in caves as potential ecological elements and not focusing solely on exotic troglobiotic species.

KEYWORDS:

• Pompilidae
• cave
• subtroglophile
• ecology
• Sonoran Desert
• Arizona

Acknowledgements

I sincerely thank Martie Maierhauser, along with her husband, the late Joe Maierhauser, for their many years of stewardship of the very special and significant resources at Colossal Cave Mountain Park. The preservation and growth of the Park under their stewardship is a testament to their appreciation for the values present in the Park and recognition of the need to protect and conserve these public resources. Martie Maierhauser also provided the 45 years of precipitation data for the Park.

Special thanks are extended to two persons in particular, William D. Peachey and Randy Gruss, without whose significant contributions of time and effort over many years our research at the Park could not have been accomplished. I thank Anita L. Mastrilli, Tom C. Bethard and Esty Pape for their long-term contributions and dedication to studies in the Park. Anita Mastrilli assisted with wasp data collection in the 1992 and 1993 seasons. I thank my good friends Darrell Ubick (California Academy of Sciences at San Francisco) and the late Vincent D. Roth (former Director of the American Museum of Natural History-Southwestern Research Station at Portal, Arizona) for identifying spiders associated with this study. William Peachey provided information on the karst speleogenesis in the Park and the base map of Arkenstone Cave. I also thank the many others who contributed to the various facets of the studies in the Park. All of the above have been faithful stewards of the Park resources for many years and their efforts are commended. I thank Michael Haverty for his helpful suggestions on statistical analyses. I thank Esty Pape for proofreading the manuscript. I thank the two anonomous reviewers, whose constructive input has greatly improved this manuscript. All photos are by the author unless otherwise noted.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00222933.2024.2374542

Additional information

Funding

The author(s) reported there is no funding associatedwith the work featured in this article.