Bug FAQField digger wasp
Mellinus arvensis · Order: Hymenoptera · Family: Crabronidae
The field digger wasp is a yellow and black insect with a notably narrow waist. Females are larger than males and dig solitary underground nests in sandy soil, provisioning them with flies for their larvae. They are most common from July through late September or October, especially in areas recovering from forest fires.
Source: Wikipedia
How to recognize it
They are yellow and black like many wasps but have a slimmer waist.
Source: Wikipedia
Size
Females are larger than the males.
Source: Wikipedia
Where it lives
Their nests are underground burrows in sand or soil.
Source: Wikipedia
What it eats
Females stock their underground cells with flies for the developing larvae.
Source: Wikipedia
Life cycle
Field digger wasps hunt alone but live in loose colonies. Females dig multi-cell nests in sand, lay eggs, and supply each cell with flies.
Source: Wikipedia
When you see it
Adults are active from July through late September or October.
Source: Wikipedia
Where it comes from
They become the dominant wasp species right after forest fires.
Source: Wikipedia
Lookalikes
They may be confused with other yellow-and-black wasps, but their narrower waist sets them apart.
Source: Wikipedia
More photos
Questions people ask
When are field digger wasps active?
They are most commonly seen from July to late September or October.
Source: Wikipedia
What do field digger wasps look like?
They are yellow and black with a slimmer waist than typical wasps.
Source: Wikipedia
Where do field digger wasps build their nests?
They dig underground burrows in sandy soil to create nests.
Source: Wikipedia
What do the larvae eat?
The females stock each nest cell with flies for the larvae to consume.
Source: Wikipedia
Same family (Crabronidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Mellinus_arvensis
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-24 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.