What's That Bug? does not endorse extermination

Subject: Green June Beetle Grubs
Location: Rose Hills
January 27, 2014 12:21 pm
Happy New Year Daniel,
I hope all is well on the other side of the hill.
I wanted to share & get your thoughts on my morning find. I lifted a board in the back yard known to harbor a variety of chicken treats and much to my shock founds grubs the size of fingers! I diligently fought off 5 chickens & saved them for their photo shoot.
A little internet research tells me they are Green June Beetle Larvae. (I used this site: http://blog.growingwithscience.com/2008/10/bug-of-the-week-green-june-beetle/)
One telltale trademark is that they flip over onto their back to crawl away. They are pretty fast at doing that too. Gave me a hard time photographing them.
I am pretty sure this is what I have. My conundrum is, now what do I do with them? I imagine I should just put them back and make the girls wait for when they emerge to fly and they can chase them around the yard. We had a lot last year and a repeat would be nice… for the chickens. I’m just not sure how much of a pest they really are in greater Los Angeles nor do I feel right intervening in the circle of life.
Here are the photos I managed to get.
Kind regards
Signature: joAnn Ortiz


Crawly Back

Hi joAnn,
Thank you so much for your kind greeting and wonderful contribution.  We love the common names Crawly Back for the larva and Figeater for the adult Green Fruit Beetles,
 Cotinis mutabilis.  Crawly Back is a reference to the manner in which the larvae move through substrate, which you noted in your letter.  Our initial inspection of the link you provided did not indicate the home base for the blogger, and there are other Green June Beetles in the genus, but our western species is Cotinis mutabilis.  In our opinion, Crawly Backs are beneficial as they help to break down materials in the compost pile, and though your letter did not mention a compost pile, we suspect that if you have chickens, you also have a compost pile.  We would release the Crawly Backs into the compost pile.

Crawly Backs

Crawly Backs

Close Up of a Crawly Back

Close Up of a Crawly Back


What's That Bug? does not endorse extermination
Location: Rose Hill, Montecito Heights, Los Angeles, California

One Response to Crawly Backs

  1. Cassandra L. Oelke says:

    Corona, California
    While walking my dog this morning (approximately 9:15am) I found a Crawly Back scooting along the edge of a lawn and brought it home to “Google it” after an appointment. Not knowing what it was outside of a grub I put it in a clean jar with some soil from my yard along with some tomato leaves, small tomato, parsley and poked plenty of holes in the lid for ventilation. Put a note on the jar not to disturb my creature and don’t open.
    I’m excited to learn what this grub baby will grow up to be. I’m going to keep it in the jar (hopefully it’s a proper environment), watch it mature and release it.

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