What's That Bug? does not endorse extermination

grub in the wood
Location: houston, texas
May 2, 2011 10:24 am
I had a water oak that died a year ago. I chopped it down and was splitting the wood for firewood. This grub fell out. It was burrowed in the middle of the log and is about 2 and half inches long. What is it, and could it be the reason the tree died?
Signature: shawn

Round Headed Borer Larva

Hi Shawn,
This is the larva of a beetle in the family Cerambycidae, the Longhorned Borers.  The Larvae are known as Round Headed Borers.  You can compare your images to those posted to BugGuide.  The BugGuide information page indicates this about food:  “Larval habits: Most species feed within dead, dying or even decaying wood, but some taxa can use living plant tissue. Girdlers (adults of the Onciderini, larvae of genera in the tribes Methiini, Hesperophanini and Elaphidiini) sever living branches or twigs, with the larvae developing within the nutrient-rich distal portion. The larvae of a few species move freely through the soil, feeding externally upon roots or tunneling up under the root crown.”  BugGuide goes on to reveal this about the life cycle:  “The life spans in temperate regions typically range from 1 to 3 years, but cycles of 2-3 months to decades have been documented. Most of the lifetime is spent in the larval stage; the adults usually emerge, disperse, reproduce, and die within a few days to months. Cellulose digestion appears to be aided primarily by enzymes rather than symbiotic microorganisms. In many cases, Cerambycidae are primary borers, providing a vital ‘first step’ in the biorecycling of wood.”  The other major family of wood boring beetles are the Metallic Wood Borers in the family Buprestidae.  The Buprestid Larvae are known as Flat Headed Borers.  You may compare the Round Headed Borers to the Flat Headed Borers by looking at these images on BugGuide.  Except in rare cases, Borers feed on dead and dying wood and they do not infest the wood of healthy trees, so we doubt that the death of the tree was caused by this Round Headed Borer.

Round Headed Borer Larva

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

11 Responses to Round Headed Borer Larva

  1. ethan says:

    just found one in the base of my 50 year old, invasive yuonimous (sp?) fire/smoke bush… in SE CT
    crazy.. thanks for the info

  2. Sally Smith says:

    I Just found one in the roots of a big Redwood in my yard while digging holes for sunflowers. OH he is ugly and huge.

  3. Stiv says:

    It’s hard to kill. He lives in the tree till 7 years. The most successful way to destroy the face is microwave treatment. http://beetlestop.com/ – here sell this device.

  4. Please describe the temporary care, feeding, and procedure for translocating Round Headed Borer Larva rescued from split logs. Thanks

  5. Please describe the temporary care, feeding, and procedure for translocating Round Headed Borer Larva rescued from split logs. Thanks
    What if I drilled a 3 inch deep 5/16 inch diameter whole and placed them well inside, facing in mouth first.

  6. Thomas says:

    Hi yeah I live in Riverside California and was hired to remove 4 dead cypress trees from a property, decided to bring the wood home and split it for firewood. These 4 dead cypress trees were riddled with the Flatheaded borer larvae, every biscuit I split, fell out 5-10 larvae at a time. I read that they go for stressed, dyeing and/or dead trees but the numbers in which these trees were infested with beg the question of what really happened.

  7. FRANCES MUNSCHAUER says:

    White 1.5 inch hard plastic looking thing with regular bumps found in soil not curved? I just found one turning brownish with a sprout sticking out. What is this?

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