Harlequin Flower Beetles

Subject: Black Yellow Beetle
Location: Sanford, FL
May 10, 2014 3:25 pm
We live in Sanford, FL and have a screened in porch that is sealed up. These beetles keep appearing and I am wondering if they are coming out of a plant, pygmy date palm or other.
We cannot identify where they are coming from and think they may be living in the large potted palm, that is 24″ tall by 18″ wide.
Do you know what this beetle is and does it live in plant soil? When I find them, they are not dirty or wet. I have soaked the plant and compressed the top soil to see if they are coming out the top, but no soil is disturbed. Thought maybe the bottom of the planter as it was up on wheels, but I sat it on the floor and still they appear. In 3 months we have had over 20 of them appear and all the same type, but different patterns on their backs.
Signature: Mike

Harlequin Flower Beetles
Harlequin Flower Beetles

Hi Mike,
These are Harlequin Flower Beetles,
Gymnetis caseyi, and as you have indicated, the markings can be quite variable, with some individuals almost entirely yellow and others mostly black.  We thought assisting you in figuring out their place of origin would be easy, but according to BugGuide:  “Adults readily come to bait. However, little is known about the habits of the larvae. Ritcher (1966) reported three third-stage larvae collected December 31, 1919, at Blue Mott, Victoria Co., TX in rotten moss in a hollow anacua (Ehretia anacua) tree.”  Most Scarab Beetle larvae we know about are found in soil or in rotting wood.

8 thoughts on “Harlequin Flower Beetles”

  1. Hello Mike,

    I am an avid insect collector and would be thrilled if I could visit Your property and collect some of Your beetles. That species is native to the Southwestern United States and has recently spread to Central Florida. I would appreciate it if I could make the 1.5hr or so drive to Your location instead of the 2 day trip to Texas to collect some lol. Please let Me know, Eddie.

    Reply
  2. Hello Mike,

    I am an avid insect collector and would be thrilled if I could visit Your property and collect some of Your beetles. That species is native to the Southwestern United States and has recently spread to Central Florida. I would appreciate it if I could make the 1.5hr or so drive to Your location instead of the 2 day trip to Texas to collect some lol. Please let Me know, Eddie.

    Reply
    • BugGuide does not provide any information on diet, however for members of the subfamily Cetoniinae to which it belongs, BugGuide states: “Many found on flowers, where feed on pollen.” There is no indication they are harmful to plants.

      Reply

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