Wedge Shaped Beetle

Subject:  Feathery Tiara
Geographic location of the bug:  Andover, NJ
Date: 08/03/2018
Time: 03:14 PM EDT
Your letter to the bugman:  Hi Daniel,
I found this very festive beetle (I think?) on my common milkweed today.  I’ve gone through several searches for beetles with feathery antenna  and can’t find anything that quite matches this little guy.  The overall look of it makes me think it might be a nymph form of something.  Hoping you can ID it for me.
How you want your letter signed:  Deborah Bifulco

Wedge Shaped Beetle: Macrosiagon limbata

Dear Deborah,
This is a Wedge Shaped Beetle in the family Ripiphoridae, and thanks to this image on BugGuide, we have identified it as
Macrosiagon limbata.  This is a new species in a very underrepresented genus on our site.  According to BugGuide: “Adults on flowers of goatweed (Capraria), elderberry (Sambucus), thoroughwort (Eupatorium), beebalm (Monarda), goldenrod (Solidago), mountain mint ( Pycnanthemum),” and “They go through hypermetamorphosis. The female deposits eggs on flowers frequented by bees. The first instar is a planidum, an active larva capable of climbing on a bee or bumble bee (their hosts). They are transported to the bee nest where they behave as parasitoids. The following instars don’t have legs and feed on the bee larvae and stored pollen and nectar.”  Of the family, BugGuide notes:  “bee/wasp parasites lay eggs on/near flowers, sometimes inside flower buds. Larvae attach to visiting bees and are taken back to nest, where they are internal parasites of larval hymenoptera, in some cases only in early stages. Some are reported to feed on leaves in later stages. Adults are short-lived.”  Thank you for this marvelous addition to our archives.

Thank you so very much for the ID!  I found the genus in my Beetles of Eastern NA after you gave me the id and read up a little on them.  Fascinating, and I feel so very fortunate to have seen one.  I need to start keeping a yard list of all the insects I’ve seen here. Thank you again, and have a great weekend.  I’m off to see what I can find in the garden…

You are most welcome Deborah.  There is a pretty good record of your sightings on WTB?  You can use the search engine with your name to bring them all up.

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