Common Hover Fly Parasitoid Wasp

Diplazon laetatorius · Order: Hymenoptera · Family: Ichneumonidae

Also called: Common Hover Fly Parasite Wasp, Parasitoid wasp

No source yet on danger. We have no source yet on whether it bites, stings or damages anything.
Common Hover Fly Parasitoid Wasp
Photo: Judy Gallagher, CC BY

Diplazon laetatorius is a wasp that belongs to the Ichneumonidae family, subfamily Diplazontinae. Adults drink nectar from flowers, especially those in the umbellifer family, while females lay eggs near hoverfly eggs and larvae. The wasp’s larvae develop inside the hoverfly host, eating it from within before emerging as adult wasps.

Source: Wikipedia

What it eats

Adult wasps feed on floral nectar, preferring umbellifer flowers. Females lay eggs on or near hoverfly (Syrphidae) eggs and larvae.

Source: Wikipedia

Life cycle

The developing larvae consume the hoverfly host from within, then emerge as adult wasps.

Source: Wikipedia

Where it is found in the US

Recorded in 43 of 51 states and DC. Most records: California, Illinois, Wisconsin, Texas, Minnesota, New York, Ohio, Arizona.

Darker = more records. Counts are museum and citizen-science records, not population size.

Source: GBIF

Months it is reported in the US

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Source: GBIF

More photos

Common Hover Fly Parasitoid Wasp photo 3
Photo: Steve Kerr, CC BY
Common Hover Fly Parasitoid Wasp photo 4
Photo: Adrienne van den Beemt, CC BY
Common Hover Fly Parasitoid Wasp photo 5
Photo: Healthy Yards, CC BY
Common Hover Fly Parasitoid Wasp photo 6
Photo: Jesse Rorabaugh, CC BY

Same family (Ichneumonidae)

Long-tailed Giant Ichneumonid WaspLong-tailed Giant Ichneumonid WaspMegarhyssa macruraHarmlessToothed Tiger IchneumonToothed Tiger IchneumonAmblyteles armatoriusOrchid Dupe WaspOrchid Dupe WaspLissopimpla excelsaBlack Giant Ichneumonid WaspBlack Giant Ichneumonid WaspMegarhyssa atrataCream-spotted IchneumonCream-spotted IchneumonEchthromorpha intricatoriaHarmlessBlack-tipped Orange Ichneumon WaspBlack-tipped Orange Ichneumon WaspCtenochares bicolorus

Sources

  • Wikipedia: https://en.wikipedia.org/wiki/Diplazon_laetatorius

Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia

Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.

How this page works

This is one bug's fact sheet. The colored box at the top says whether it is dangerous. Sections below cover how to recognize it, whether it is a pest, and how to deal with it. The US map shows which states have records; tap a state to see other bugs there.

Every fact on Bug FAQ comes from a named source (university extension sites, government agencies, GBIF, iNaturalist, Wikipedia). The source is linked next to each section. If we have no source for something, we leave it out.