Posted July 17, 2014
We had no correct guesses to this week’s Freak of the Week, so here’s Bob’s answer:
If you answered the larva of a Tiger Beetle, you are right on! Specifically, it is the larva of a Hairy-necked Tiger Beetle (Cincindela hirticollis). The sand grains show that this animal is very tiny, and the two large eyes prove that it is not a burrowing spider which would have either 6 or 8 eyes. Ohio has twenty species of tiger beetles, a few of which are wide-spread and common. All tiger beetles are predacious both as larvae and as adults. The larvae burrow into the sand with just the tip of their head at the sands surface exposing only their eyes and their mouth parts. They lay waiting for a small insect to come scurrying by, then dart out and grab them. If you are an ant or other small insect, they are indeed a “tiger”.
The adults of the Hairy-necked Tiger Beetle are brown to brownish-green, or in some regions even green, with distinctive marking on their elytra (wing coverings) and stiff hairs around their necks. The adults measure about 10-15 mm long – so the larvae are really very tiny (see the concealed one barely visible in the circle above and right of the mating pair). Adult tiger beetles are swift, running predators of other insects. Many people are familiar with the common bright green Six-spotted Tiger Beetle (the only bright green tiger beetle in Ohio), whose life style is very similar. They sometimes run off or fly off as you approach them, landing a short distance away.
Hairy-necked Tiger Beetles have a continent-wide distribution, from sandy beaches on New Yorks Long Island, all the way to Pacific coast of Oregon. Within this huge range however, they are restricted to sandy beaches of larger lakes as well as ocean coastal beaches. In Ohio, they are listed as State Threatened and across their range they are described as “populations in decline”. One of the biggest threats is disturbance of beach habitats. Especially problematic is the custom of driving ATVs and four-wheel vehicles along the beaches that they inhabit. In this regard, they are like the endangered Piping Plover – which pits beach driving fishermen against the welfare of the animal. On a nature preserve like Sheldon’s Marsh they are well protected.
Curator Emeritus of Natural History