Bug FAQStylops melittae
Stylops melittae · Order: Strepsiptera · Family: Stylopidae
Stylops melittae is a parasitic insect that lives inside sand bees of the genus Andrena, especially those that collect pollen from many plant species (polylectic). Infested female bees become sterile and look more like males, with reduced pollen-gathering structures and a flatter abdomen. The parasite releases many mobile larvae onto flowers, where they hitch a ride on pollen back to bee nests, and most infected bees are seen from March to May.
Source: Wikipedia
How to recognize it
Female sand bees parasitized by Stylops melittae lose the ability to reproduce and show male-like coloration, a flatter abdomen, and a reduced pollen-gathering apparatus.
Source: Wikipedia
Where it lives
The parasite mainly targets sand bee species that visit a variety of flowering plants; specialists that visit only one or few plant species are less often affected.
Source: Wikipedia
What it eats
Female Stylops melittae release large numbers of motile primary larvae onto blossoms, which are then carried with pollen to the nests of their sand-bee hosts.
Source: Wikipedia
Life cycle
After entering a bee host, the parasite moves through several molts, settles in the abdomen, and its front part breaks through between abdominal segments to pupate outside the host’s body.
Source: Wikipedia
When you see it
Most infected bees appear in the early part of the year, typically from March through May, although a second generation can occur.
Source: Wikipedia
Where it comes from
Stylops melittae is found wherever its sand-bee hosts occur, as it is a member of the order Strepsiptera that parasitizes Andrena bees.
Source: Wikipedia
Lookalikes
The appearance of female Stylops melittae varies widely, especially in the shape of the cephalothorax, which has led to many previously described host-specific species now merged into this single species.
Source: Wikipedia
More photos
Questions people ask
Which sand bees are most likely to be parasitized by Stylops melittae?
It mainly parasitizes polylectic Andrena sand bees that collect pollen from many different flowers, while specialists on few plant species are less often affected.
Source: Wikipedia
When are Stylops-infested bees most commonly seen?
Infested bees are most common from March to May, with most emerging in a single generation during this period.
Source: Wikipedia
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Stylops_melittae
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Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.