Leptoglossus occidentalis (western conifer-seed bug)

Leptoglossus occidentalis is a member of a family of true bugs called the Coreidae, which is part of the order Hemiptera. It is an invasive insect that has recently established itself in western Europe and the UK.

There are around 2,000 species of coreids world-wide, some of which are amongst the largest terrestrial insects. Some members of this family, such as Leptoglossus occidentalis, have enlarged leaf-like structures on their hind legs giving the family one of its common names: the leaf-footed bugs.

Coreids are found throughout the world but show the greatest diversity in tropical and semi-tropical regions. They are primarily phytophagous - they feed on plants.

Some coreids exhibit interesting behaviour such territorial defence, gathering in large numbers and carrying their eggs to protect them.

Less than 1 in 10 coreid species are regarded as agricultural pests, but a number of economically important species belong to the genus Leptoglossus.

Leptoglossus occidentalis was first described by Otto Heidemann in 1910.


Leptoglossus occidentalis was previously limited to western North America. In the past 50 years it has increased its range in North America and in the last 10 years has become established in many European countries including the UK.


It feeds on a number of trees from the pine family (Pinaceae), with nymph feeding causing significant seed loss in commercially important crops such as Douglas fir (Pseudotsuga sp.).

Species detail

  • Leptoglossus occidentalis

    There are more than 40 species of Leptoglossus, and a quarter of them are considered agricultural pests. Leptoglossus occidentalis is one of them. Find out more about this species and its relatives.


Laurence Livermore
Junior Researcher (Hemiptera: Heteroptera)

A word from the author

"I chose Leptoglossus as species of the day because I am currently working on the Coreidae and it’s a recently introduced species that people may find in their gardens, especially in southern England."

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Mitchell. 2000. Leaf-Footed Bugs (Coreidae). In Schaefer, CW and Panizzi [Ed]. Heteroptera of Economic Importance. 337–403.

Schuh and Slater, Dr 1995. True Bugs of the World (Hemiptera: Heteroptera). Classification and Natural History. i-xii, 274–278.