Monday, August 23, 2010

Tiger Beetle Larva

I’ve been busy searching for Tiger Beetles this summer. I’ve found adult specimens of three species and have been anxious to find my first larva. The larvae are found in burrows that they create in the soil. The trick is to find an active burrow and then wait for the larva to come to the entrance where it will wait to ambush small insect prey. My most recent search revealed many pinhole sized burrows in the clay soil.

There are many things that make small holes in the ground. I’ve been fooled by bees into thinking that their burrows were those of tiger beetle larvae, but I’ve never seen a bee small enough to fit into a pin hole. It’s been a couple of weeks since I’ve seen any adult tiger beetles in this location, so I’ve been expecting that their eggs would hatch and the resulting tiny larvae would dig tiny burrows. These holes looked like just what I had imagined finding.

I settled down to wait for something to show itself in the hole. After a few minutes, I noticed that there was now a reflection where before the hole had been dark. There was something in the hole.

I managed to take several photos, but my camera doesn’t do very well with pinhole sized subjects. Fortunately, I have a book that shows an unfocused picture of a tiger beetle larva at the entrance to its burrow and my photo is a very close match. As the subjects grow I should be able to get some better shots.

I found the pin hole burrows in this area that was earlier filled with adult Cicindela rufiventris. I’m assuming that the larvae represent that species.


  1. What patience you have. I've often wondered what lurked beneath the many holes one finds in the soil, but I've never sat and waited to see what would come out of one! ~karen

  2. Steve, what are the other two adult species you have found this year?
    Bill Hull

  3. That's a tiger beetle larva alright. Whether it is rufiventris or punctulata or some other species remains to be seen. If you want an interesting (albeit long-term) project, you can extract the larva from its burrow, place it in a container of soil, and rear it to adulthood. I've got several posts dealing with techniques - just enter the search term "rearing".

  4. Karen – There’s a fine line between patience and enjoying a quiet sit in the prairie.

    Bill – Besides Cicindela rufiventris, I’ve found C. punctulata and C. sexguttata. All three are fairly common species. This is the first year I’ve taken a close enough look to identify what I’ve been seeing.

    Thanks for the confirmation, Ted. I thought about rearing a couple to adulthood and may bring one in when they get a bit larger.

  5. Thanks for tell me what the little holes are ,am not going to sit and wait for a bug to come out .