Squash Bug

Leptoglossus occidentalis

Squash Bug, Western Conifer Seed Bug, Conifer Seed Bug

Leptoglossus occidentalis MHNT Profil by Didier Descouens (CC BY-SA 4.0)
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A photo of a western conifer shield bug on a leaf Leptoglossus occidentalis
Leptoglossus occidentalis MHNT Profil by Didier Descouens (CC BY-SA 4.0)
1 of 4
A Western Conifer Seed Bug is a true bug (Hemiptera) in the Coreidae family (leaf-footed bugs). Leptoglossus occidentalis is large, with distinctive extensions in the lower back legs that have a close resemblance to a plant. L. occidentalis is native to North America, with the main foodplants consisting of pine and some conifers. Like many true bugs, Western Conifer Seed Bugs suck the sap of plants. They specifically target the seed cones and sometimes can affect seed viability.


May cause problems for nurseries and coniferous woodland.
Unlikely to affect the health of garden plants and trees.


Adults: Mature bugs are a reddish-orange brown, with pale zig-zag patterning on the wings. Likewise, there's some checkering on the edges of the wings. The very back legs get significantly wider before narrowing again. The insect is substantially more narrow than that of the common green shield bug. Nymphs: Young capsid bugs are known as nymphs; generally, they are similar in shape but paler in colour, smaller and wingless. The first nymphal stage is tiny and the body distinctively thin. The antennae are longer than the body at this point. Throughout moults, the abdomen displays two black dots which disappear when the bug is mature.


Large, brown shield bugs may be evident near the cones of pine and conifer. Can reduce seed production in the trees affected badly.











North America, Europe and the UK

Biological treatment

Unfortunately, there are currently no chemical treatments available for home gardeners that will give effective control over this insect. Seed bugs like this one are unlikely to damage garden plants so treatments are unnecessary.

Chemical treatment

There are no chemical alternatives for this insect.


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