Bug FAQBordered Wedge-shaped Beetle
Macrosiagon limbatum · Order: Coleoptera · Family: Ripiphoridae
Adults are active in summer, visit flowers such as elderberries and goldenrod, and have long elytra that extend beyond the abdomen. The species undergoes hypermetamorphosis, with legless early instars feeding on larvae or stored pollen and nectar, and later stages act as internal parasites of other insects.
Source: Wikipedia
How to recognize it
Males have comb-like antennae while females have serrated antennae. The wing covers are longer than the abdomen and spread apart at the tip.
Source: Wikipedia
Where it lives
Adults can be found on summer-blooming flowers such as elderberries and goldenrod.
Source: Wikipedia
What it eats
They have elongated mouthparts that are thought to be used for sucking nectar. Early larval stages lack legs and feed on other insect larvae or on stored pollen and nectar.
Source: Wikipedia
Life cycle
During their life cycle they act as internal parasites of other insects. They undergo hypermetamorphosis, with larvae passing through several morphologically distinct stages.
Source: Wikipedia
When you see it
Adult beetles are active in the summer months.
Source: Wikipedia
Where it comes from
It is possible their range reaches into South America, though this is not confirmed.
Source: Wikipedia
Lookalikes
They are often mistaken for tumbling flower beetles (Mordellidae) but can be told apart by their longer elytra. They also resemble false darkling beetles (Melandryidae) in appearance.
Source: Wikipedia
Where it is found in the US
Recorded in 34 of 51 states and DC. Most records: Massachusetts, Pennsylvania, Ohio, Virginia, Illinois, New York, Minnesota, Indiana.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
What flowers do these beetles visit?
Adults are commonly found on elderberries and goldenrod during the summer.
Source: Wikipedia
How can I tell this beetle apart from a tumbling flower beetle?
Look at the wing covers to this species has elytra that extend beyond the abdomen, unlike tumbling flower beetles.
Source: Wikipedia
Do the larvae have legs?
The early instar larvae are legless and feed on other larvae or stored pollen and nectar.
Source: Wikipedia
Is this beetle a parasite?
Yes, at some stage they live inside other insects as internal parasites.
Source: Wikipedia
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Macrosiagon_limbata
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.