Bug FAQPolyphagous Shot Hole Borer
Euwallacea fornicatus · Order: Coleoptera · Family: Curculionidae
Also called: Polyphagous Shothole Borer Beetle
Source: Wikipedia
Adult females are 1.9 to 2.5 mm long, while males are much smaller and have non-functional wings. The beetle breeds in living trees, carries a fungus in a mycangium, and the fungus together with massive beetle numbers kills the host. Control relies on removing infected material and preventing spread; chemicals may be used on non-food hosts.
Source: Wikipedia
How to recognize it
They are bulky and dark brown or black in color. Elytral declivity bears erect setae in rows with a costa on the posterolateral edge.
Source: Wikipedia
Size
Adult females range from 1.9 to 2.5 mm long. Males are significantly smaller and have non-functional wings.
Source: Wikipedia
Is it a pest in the house?
The beetle harms trees by tunnelling deep and cultivating fungus that blocks the tree’s vascular system.
Source: Wikipedia
Does it bite or sting?
It is not considered a health threat to people.
Source: Wikipedia
How to get rid of it
Recommended management includes sanitation of infected hosts and preventing spread of infected material. Chemical control may be used on non-food hosts, while biological control attempts have had limited success.
Source: Wikipedia
Where it lives
It breeds in a variety of live host trees.
Source: Wikipedia
What it eats
The massive beetle numbers together with the fungus kill the trees.
Source: Wikipedia
Life cycle
Larvae are legless, C-shaped, and have a hardened head capsule, typical of Curculionidae.
Source: Wikipedia
Where it comes from
It was detected in South Africa in early 2017.
Source: Wikipedia
Where it is found in the US
Recorded in 4 of 51 states and DC. Most records: California, Hawaii, Florida, Kansas.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
How does the beetle damage trees?
It tunnels deep into the wood and cultivates a fungus that blocks the tree’s vascular system, eventually killing the host.
Source: Wikipedia
How can I control an infestation?
Remove and destroy infected material and avoid moving infected wood; chemicals can be used on non-food hosts, though biological control has been largely ineffective.
Source: Wikipedia
Does it bite or sting people?
It is not considered a health threat and does not bite or sting people.
Source: Wikipedia
Same family (Curculionidae)
Green Immigrant Leaf WeevilPolydrusus formosusDamages trees, gardens or crops
Black Vine WeevilOtiorhynchus sulcatusDamages trees, gardens or crops
Nettle weevilPhyllobius pomaceusDamages trees, gardens or crops
Asian Oak WeevilCyrtepistomus castaneusDamages trees, gardens or crops
Strawberry Root WeevilOtiorhynchus ovatusDamages trees, gardens or crops
Common Leaf WeevilPhyllobius pyriDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Euwallacea_fornicatus
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 2026-10-23.