514 ENTOMOLOGICAL NEWS

A CLICK BEETLE LARVA (COLEOPTERA: ELATERIDAE) PREYING UPON AN LARVA (: MYRMELEONTIDAE)1

Dus˘an Devetak2 and Amy E. Arnett3

The snake-like larvae of Cardiophorinae, commonly called wireworms, are soil-dwelling or live in rotten decaying wood. They are elongate and smooth with a rather well-developed head with a prominent frontoclypeus and peculiar, exter- nally toothed mandibles (Klausnitzer 1991-1999; Klausnitzer et al., 2000). They are highly mobile, moving with considerable speed through substrate. Some lar- val Cardiophorinae are voracious predators, feeding on soil-dwelling and earthworms, although little is known about the specific insects upon which they feed. Antlion larvae are sand-dwelling insects and this paper documents the first case of a Cardiophorinae larva feeding on an antlion larva (Neu roptera: My r me - leontidae). Our knowledge of on both adult and larval is limited, al - though adult antlions are considered to be prey for reptiles, birds, mammals, and many invertebrates, including scorpions, , and insects (Gepp and Hölzel, 1996; Gepp, 2010). Adults are also known to be consumed by robber flies and dragonflies, and predators with raptorial forelegs, such as mantids (Man todea) and mantidflies (Neuroptera: ), have been observed to catch and eat adult antlions (Devetak, unpublished). Larval antlions in dry sandy habitats have been reported to be eaten by lizards, birds and hedgehogs (Gepp and Hölzel, 1996; Gepp and Klausnitzer, 2005; Gepp, 2010). Until now, stiletto fly (Diptera: Therevidae) larvae are the only recorded predator of larval antlions, as reported by Gepp and Klausnitzer (2005) on larvae of the European antlion, Euroleon nostras. In our study, fifty-five second- and third-instar larvae of Myrmeleon immacu- latus De Geer, 1773, and associated pit soil samples were collected on July 15, 2009, in Salmon River State Forest, Connecticut, U.S.A. The larvae were locat- ed on a steep, sandy hillside along the river, and were abundant under grasses, shrubs and small trees dotting the hill. Three spoonfuls of soil (approximately 50 mls) were collected from each pit along with each larva. During the late summer and fall of 2009, the antlions were reared in a laboratory at the University of Maribor, in Maribor, Slovenia. During inspection of the samples upon arrival to Slovenia, one individual was observed being a prey item of a click beetle larva (Fig. 1). Both the click beetle ______1 Received on April 14, 2011. Accepted on May 10, 2011. 2 Department of Biology, FNM UM, University of Maribor, Koros˘ka cesta 160, 2000 Maribor, Slo - venia. E-mail: [email protected] 3 Center for Biodiversity, Unity College, 90 Quaker Hill Road, Unity, ME 04915, U.S.A. E-mail: [email protected] Mailed on February 2, 2012 Volume 121, Number 5, November and December 2010 515 and the ant lion clearly originated in Connecticut, U.S.A., because both were in the travel container upon arrival. We noticed a small wound on the ventral part of the antlion’s abdomen where the click beetle larva pierced the cuticle by means of its mouthparts.

Fig. 1. Larva of the elaterid subfamily Cardiophorinae with its prey, third-instar larva of the antlion Myrmeleon immaculatus.

Little is known regarding predation on larval antlions. The Cardiophorinae click beetle larva, documented in this study, may be phytophagous, saprophagous or predacious. In all cases, however, they are liquid feeding and practice extrao- ral digestion (Hawkeswood, 1987; Triplehorn and Johnson, 2005). This study documents for the first time that predacious Cardiophorinae larvae are predators of antlion larvae.

ACKNOWLEDGMENTS We are grateful to Dr. Hume Douglas (Carleton University, Ottawa, Canada) for confirmation of identification of a cardiophorine larva. The click beetle larva is deposited in the University of Mari - bor collection. We thank Dr. Shaun Winterton (Brisbane, Australia) for helpful suggestions on an early version of the manuscript. The first author acknowledges the partial financial support from the state budget by the Slovenian Research Agency (Grant No. P1-0078 Biodiversity) and the second author acknowledges financial support from Unity College. 516 ENTOMOLOGICAL NEWS

LITERATURE CITED

Gepp J. 2010. Ameisenlöwen und Ameisenjungfern. Myrmeleontidae. Third ed., Westarp Wis sen - schaften, Hohenwarsleben. Gepp J. and H. Hölzel. 1996. Ameisenlöwen und Ameisenjungfern – Myrmeleonidae. Ziemsen Ver lag, Wittenberg Lutherstadt, 108 pp. Gepp J. and B. Klausnitzer. 2005. Therevidenlarven (Dipt., Therevidae) als Prädatoren des Ameisen löwen Euroleon nostras (Neuroptera, Myrmeleontidae). Entomologische Nachrichten und Berichte. 49(1): 25-27. Hawkeswood T. J. 1987. Beetles of Australia. Angus & Robertson Publishers, Sydney, Australia. Klausnitzer, B. 1991-1999. Die Larven der Käfer Mitteleuropas. Band 1-5. Goecke & Evers, Kre - feld & G. Fischer, Jena. Klausnitzer B., F. Hieke, M. Uhlig, and L. Behne. 2000. Coleoptera – Käfer. In: Stresemann E., Hannemann H.-J., Klausnitzer B., Senglaub K. Exkursionsfauna von Deutschland. 2. Wirbellose: Insekten. 9th Ed. Spektrum Akademischer Verlag, Heidelberg, pp. 314-552. Triplehorn, C. A. and N. F. Johnson. 2005. Borror and DeLong’s introduction to the study of in - sects. Seventh ed., Thomson, Brooks/Cole, Belmont, CA. 888 pp.