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I noticed this small (~1cm long) insect on my rose bush in Santa Cruz, California, U.S.A.. I also noticed that all the scales, usually infesting my rose, were missing. I was pleased and am currently attributing this attrition to the new visitor.

Any thoughts on what this insect may be and if it is indeed to be commended for it's excellent work?

Unidentified Insect on Rose Bush, note no scales present. Unidentified Insect on Rose Bush, note no scales present. Unidentified Insect on Rose Bush, note no scales present.

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    Nice pictures! Not that I know the bug, but should help immensely for a better entomologist.
    – Ecnerwal
    Feb 14 '17 at 1:45
  • i have a working rule that if it's not pollinating or actively eating a pest, it's there to feed on my plants in some not nice way.
    – Graham Chiu
    Feb 14 '17 at 6:04
  • Side note: if you have a constant scale problem and now beetles, I recommend you check environemental parameters like water, drainage, temperature, wind, nutrition in soil.... Repeat or multiple infestations can be an indication that your rose is generally "weak", i.e. that something larger is amiss.
    – Stephie ♦
    Feb 14 '17 at 8:41
  • I hate doing a thumbs down on any living creature. In my experience most beetles are after dead organic matter. It is their larvae/grubs that do the damage. Sure looks like the Rose Weevil. I'd be digging down in the roots to find larvae...in the spring. There is a BT designed just for beetles. I'd check that out. Killing just one ain't gonna help.
    – stormy
    Feb 14 '17 at 18:50
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I'm not an entomologist but by googling, it looks to be a Rose Weevil or Fuller Rose Beetle aka Naupactus (Asynonychus) godmani.

It doesn't look like it's a goodie to have on your roses

enter image description here

The damage done by this beetle is to the foliage of the host plant by the adults and the root system is damaged by the larvae. Death of the host rose bush is a very real possibility if not controlled. Part of figuring out the pest we have is in recognition of the damage the particular insect does. With the fuller rose beetle, the leaf damage is typically serrated (notched edges), creating a ragged appearance. Under heavy infestations, these beetles can easily consume an entire leaf, leaving only the midrib of the leaf! The younger larvae eat at the root hairs or rootlets, and the older larvae girdle the lateral roots of the host plant. Such damage to the root system will result in stunted growth since the roots are unable to effectively take up the nutrition it needs. Weakening of the root system also makes it a good candidate for fungal infections that will aid in the death of the rose. Early recognition of such a problem is priceless, making the treatment of fuller rose beetles imperative.

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  • Naupactus godmanni doesn't look nice at all.
    – dakab
    Feb 14 '17 at 5:27
  • Thanks for the slick response. I think you are spot on. I sprayed the rose last night with neem and then found the Bugger this morning had survived. My first attempt to terminate it resulted in escape, but now it's on my radar. Thank you very much for the help.
    – J.P.M.
    Feb 14 '17 at 19:21

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