What's That Bug? does not endorse extermination

Giant larva in my copost bin?
Location: Burbank, California
May 1, 2011 5:39 pm
We get lots of interesting creatures in our compost and I see many of these larve that are about as thick around as my middle finger. Last time I was turning the compost, I pulled a few out to take a picture and hopefully identify them.
I hope you can help, my kids and especially interested in learning what they areso they can tel their classmates at school.
Our guess was perhaps tomato bug larvae?
Signature: Curious Dad


Hi Curious Dad,
You have Crawlybacks, the larvae of the Green Fruit Beetle or Figeater,
Cotinus mutabilis.  The name Crawlyback is discussed by Charles Hogue in his awesome book, Insects of the Los Angeles Basin, where he writes that the larvae “obtain purchase on the substratum with traverse rows of still short stout bristles on the back of the thorax.”  The larvae do not affect lawns or grass.  The bright metallic green adults are active in August and September.


What's That Bug? does not endorse extermination
Location: California

One Response to Crawlybacks in the compost pile

  1. Kristin says:

    We had a big population of these in OUR compost heap in the High Desert of California years ago. I’ve always wondered what they were, and I just found out what they are thanks to this site 🙂

    My step-son had pet rats, and for “fun” (sorry!) he put a couple of these into the rat’s cage and the rats went NUTS over them- the rats loved them and acted like they hadn’t eaten in days! I assumed the grubs were not beneficial so I let the rats have a go at it on the compost heap and I never saw rats move so fast. Maybe rats do have a benefit to mankind after all?

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