Currently viewing the category: "Wedge Shaped Beetles"
What's That Bug? does not endorse extermination

Subject: What is it?
Location: New Jersey
July 13, 2014 8:46 pm
I saw this bug sipping the nectar of a butterfly weed plant – asclepias.
Thanks so much for your help!
Signature: Bridget

Wedge-Shaped Beetle

Wedge-Shaped Beetle

Dear Bridget,
We now do most of our research online, but in the case of your unusual beetle, we turned to our brand new copy of Beetles of Eastern North America by Arthur V. Evans and we quickly identified your beetle as
Macrosiagon flavipenne, one of the Wedge-Shaped Beetles in the family Ripiphoridae.  According to Evans:  “Adult Ripiphrids live for only a few days and information on their lives is fragmentary.  They rest on low grasses or flowers and meet in mating swarms.  The comblike antennae on the male persumably increase its ability to locate females emitting sexual pheromones. …  All species undergo hypermetamorphosis.  Early instars feed internally on the larvae of other insects, whereas the later stages feed externally on their hosts. …   Macrosiagon larvae parasitize wasps in several families, including Vespidae, Sphecidae, Crabronidaeand Tiphidae.  Of the species Macrosiagon flavipenne, Evans writes:  “Abdomen black (male) or red (female). … Adults active in summer, found mainly on flowers.”  There is a differing spelling of the species name on BugGuide, where it is listed as Macrosiagon flavipennis.  BugGuide also notes:  “Females lay eggs on flowers. Eggs hatch into an active larva that attaches itself to visiting wasp. It is carried back to wasp nest where it burrows into a host larva.”

Wedge-Shaped Beetle

Wedge-Shaped Beetle

Thank you so much for identifying the beetle. I’ve been trying to figure it out for days. You’re the best!

What's That Bug? does not endorse extermination

Subject: Beautiful looking antler(ed) bee
Location: Milton, Ontario
September 1, 2013 6:35 pm
Hi
I’m starting to take macro shots of insects, I found this ’bee’ on a trip to an apple orchard, the little guy was holding a weird looking leave of one of the apple trees. I was able to take a couple of nice pictures of it, profile and front. I haven’t seen anything like this before. I was wondering if you could help me identify it
Thanks!!
Signature: DrZhark

Wedge Shaped Beetle

Wedge Shaped Beetle, genus Ripiphorus

Dear DrZhark,
We are very excited with your submission, which we believe creates a new genus on our site.  Though your insect resembles a bee, the antennae are very characteristic of certain beetles, especially Scarabs.  We did some research and quickly found a family on BugGuide known as the Wedge Shaped Beetles, Ripiphoridae, which is described as:  “Small to medium-sized beetles, sometimes found on flowers. Many have fan-like (flabellate) antennae, esp. males. Abdomen blunt. Tarsal formula 5-5-4.”  Within that family is a genus
 Ripiphorus which is described on BugGuide as:  “Body appears wasp-like…with very short elytra (looking like large tegula) and long, exposed wings…but with very un-wasp-like antennae.  Male antennae are biflabellate, i.e. with two rami (= side-branches) at each joint, and the rami usually of roughly equal size at each joint of the relatively short main axis of the antennae.”  BugGuide also notes:  “Females lay eggs on flowers (often on buds). Eggs hatch into active first stadium larvae (triungulins) which hitch a ride on bees to their nests. Once there they feed on the brood: first as internal parasites, and later in their development as external parasites…a habit otherwise almost unknown in Coleoptera(3)  Adults are very short-lived: in many species the males live no longer than a day; females may be similarly short-lived but tend emerge over a longer period” and “Females are more commonly seen than males because they visit flowers to deposit eggs; and males are shorter lived.  The genus badly needs revision; only a fraction of spp. can be confidently identified.”  We will contact Eric Eaton to see if he can add any information.

Wedge Shaped Beetle, genus Ripiphorus

Wedge Shaped Beetle, genus Ripiphorus

Daniel:
Not only do I agree with the identification, but I learned a few things about these beetles I did not know before myself!  Like, how short-lived they are.  I think the information you provide through the Bugguide page is more than thorough.  Nice work.
Eric

Thank you for your help, and running your magnificent web site.
I had no idea the beetle was rare, I only thought it was unusual. I was very lucky to have found it =).  I left it unharmed and moved on.
I have higher resolution versions of the pictures:
http://www.flickr.com/photos/99458228@N05/9639763141/
http://www.flickr.com/photos/99458228@N05/9642999006
Thanks again

What's That Bug? does not endorse extermination

two-toner
Location: Jamestown, RI
August 22, 2011 3:06 pm
This little guy was visiting the mountain mint 8/19/11.
Signature: PeeGee

Wedge Shaped Beetle

Dear PeeGee,
At first we thought this looked like a Tumbling Flower Beetle in the family Mordellidae, but when we couldn’t find a match on BugGuide, we broadened our search, and eventually identified it as a Wedge Shaped Beetle,
Macrosiagon dimidiata, which we found on BugGuide where this information is provided:  “Adults said to like to feed on Mountain-mint, Pycnanthemum spp.(1)  Larvae, like other members of the genus, are parasitoids of Hymenoptera.”  BugGuide expands on that with this remark:  “Females lay eggs on flowers, larvae hitch a ride from one of its hosts (Hymenoptera) and parasitize the brood.”  We are creating a brand new Beetle subcategory to house your submission.

What's That Bug? does not endorse extermination