western conifer seed bug

(Leptoglossus occidentalis)

Conservation Status
western conifer seed bug
Photo by Emily
  IUCN Red List

not listed


not listed


not listed


Western conifer seed bug is a common and widespread, terrestrial, true bug. It is most often encountered in the fall, when it seeks shelter for the winter.

Adults are to ¾ in length.

The front (anterior) thoracic shield (pronotum) is covered with long, erect hairs.

The upper (dorsal) side of the abdomen is mostly hidden by the wings and is rarely visible except in flight. It is orangish-yellow with black markings, including two narrow, elongated, lance-shaped longitudinal marks in the center; and five broad, horizontal patches on each side.

There are two pairs of wings, and they are held flat over the body when at rest. Between and at the wing bases there is a triangular plate (scutellum). The forewings (hemelytra) on the mature adult are longer than the abdomen but do not completely cover the sides of the abdomen. The sides of the abdomen are exposed and appear conspicuously striped when the wings are closed. The hemelytra have a thickened section at the base and a thin membranous section at the tip with a clear dividing line between the two. The thickened basal part is comprised of a narrow area (clavus) behind the scutellum when the wings are closed, and the remaining broad marginal area (corium). There is a yellowish-white, horizontal, zig-zagged line on the corium that is narrow and confined to the veins. At the end of the corium there is a small but distinct triangular area (cuneus). The hindwings are thin, membranous, and concealed under the forewings.

The head is small, much narrower and somewhat shorter than the pronotum. At the front of the head there is a rounded lobe that projects forward. There is a pair of large compound eyes and a pair of small simple eyes (occelli). The mouth parts are optimized for piercing and sucking. They take the form of a long, 4-segmented beak that extends along the underside of the body between the legs. It consists of 4 hair-like blades (stylets) with sharp tips enclosed in a 4-segmented sheath. There are two channels in the beak, one spitting out saliva to keep the food flowing, and one for sucking in liquid food. The two lower jaw-like structures (maxillae) and two lower lips do not have feeler-like structures (palpi) attached. The antennae are exposed, conspicuous, and long, much longer than the head. They have four segments. The first segment is chestnut orange with a black longitudinal stripe.

The third segment (femur) of the hind leg is is stout and spurred below. The fourth segment (tibia) is greatly dilated. The dilations are nearly equal in length and are less than 70% of the length of the tibia. They are lance-shaped and are not scalloped. The outer dilation is slightly wider than the inner. The feet (tarsi) have only 3 segments.




Total length: to ¾


Similar Species






One generation per year: Late May to the onset of cold weather in the fall




When in flight the wings create a loud buzz. Unlike similar-looking assassin bugs, they do not bite. When handled they squirt a foul-smelling chemical from glands on the sides of their bodies that is an effective deterrent. As the weather turns cold in the fall they often bask in the sun on the south side of human dwellings.


Life Cycle


Adults emerge in late May or early June. The female lays rows of 1 16 long eggs on needles of host species. The eggs hatch in about 10 days. The young (nymphs) pass through 5 instar stages before becoming an adult. Adults overwinter.


Nymph Food


Developing seeds and early flowers of host species


Adult Food


Sap from green cones and twigs of pine, hemlock, spruce, and fir.


Distribution Map



7, 27, 29, 30, 82.




Common and widespread



Hemiptera (true bugs, hoppers, aphids, and allies)  


Heteroptera (true bugs)  


Pentatomomorpha (pentatomomorph bugs)  


Coreoidea (leaf-footed bugs and allies)  


Coreidae (leaf-footed bugs)  


  Tribe Anisoscelini  





Narnia anaticula


Common Names


pine seed bug

western conifer seed bug

western conifer-seed bug













The thickened basal portion of the front wing that lies between the clavus and the membrane of insects in the family Hemiptera. Plural: coria.



On insects and arachnids, the third, largest, most robust segment of the leg, coming immediately before the tibia. On humans, the thigh bone.



The forewing of true bugs (Order Hemiptera), thickened at the base and membranous at the tip. Plural: hemelytra.



The developmental stage of arthropods between each molt; in insects, the developmental stage of the larvae or nymph.



Simple eye; an eye with a single lens. Plural: ocelli.



The exoskeletal plate on the upper side of the first segment of the thorax of an insect.



The exoskeletal plate covering the rearward (posterior) part of the middle segment of the thorax in some insects. In Coleoptera, Hemiptera, and Homoptera, the dorsal, often triangular plate behind the pronotum and between the bases of the front wings. In Diptera, the exoskeletal plate between the abdomen and the thorax.



On insects, the last two to five subdivisions of the leg, attached to the tibia; the foot. On spiders, the last segment of the leg. Plural: tarsi.



The fourth segment of an insect leg, after the femur and before the tarsus (foot).






Visitor Photos

Share your photo of this insect.

  This button not working for you?
Simply email us at info@MinnesotaSeasons.com.
Attach one or more photos and, if you like, a caption.


    western conifer seed bug      

Alfredo Colon

    western conifer seed bug      

Nicky Clark

    western conifer seed bug      


    western conifer seed bug   western conifer seed bug  
    western conifer seed bug      
MinnesotaSeasons.com Photos





Western Conifer Seed Bug
  Western Conifer Seed Bug  

Copyright DianesDigitals

Western Conifer Seed Bug
Andree Reno Sanborn
  Western Conifer Seed Bug  

Leptoglossus occidentalis

This bug used to be only in the west but now is common in the northeast US and Canada. Harmless to humans but it does make quite a stink if you pick it up or touch it!


has infrared receptors and is able to exploit the difference between cones and needles in the infrared spectrum, and zero in on cone-laden conifers from afar. This insect is a specialist herbivore that feeds on the contents of developing conifer seeds (from http://www.ubcbotanicalgarden.org/potd/2009/01/pinus_monticola_and_leptoglossus_occidentalis.php)

Leptoglossus occidentalis (Western Conifer Seed Bug)
Allen Chartier
  Leptoglossus occidentalis (Western Conifer Seed Bug)  



Visitor Videos

Share your video of this insect.

  This button not working for you?
Simply email us at info@MinnesotaSeasons.com.
Attach a video, a YouTube link, or a cloud storage link.


Other Videos
  Leptoglossus occidentalis

Published on Dec 30, 2014

Western Leaf-footed Bug found walking majestically in our office this December 30, 2014 , Burnaby, BC

  INSECTOS, Leptoglossus occidentalis en Móstoles
José Martín Roldán

Uploaded on Nov 8, 2010

El insecto Leptoglossus occidentalis, es un chinche de origen americano. Se ha localizado en Europa, primeramente en Italia en 1999 y en 2004 en Cataluña (España). Es un chinche (Heteroptera, Coreidae), de color marrón, que se diferencia de otros ibéricos rápidamente, por el ensanchamiento de las tibias en las patas posteriores. En los élitros con dibujo enladrillado, destaca en blanco la forma de una hache minúscula, invertida en el opuesto.
El insecto se encontraba en una crasulácea, en un jardín de Móstoles, donde abundan los pinos ya que precisamente se alimenta de las partes nuevas y blandas de dichos árboles.

Google Translate: The insect Leptoglossus occidentalis is a bug of American origin. It is located in Europe, primarily in Italy in 1999 and 2004 in Catalonia (Spain). It is a bug (Heteroptera, Coreidae), brown color, which differs from other Iberian quickly, widening the lukewarm on the hind legs. In the elytra with brickwork drawing highlights in the form of a white hache tiny, inverted on the opposite.
The insect was in a crasulácea, in a garden of Mostoles, pine trees abound precisely because it feeds on new and soft parts of these trees.

  Invasor Bug - Leptoglossus occidentalis (Heidemann, 1910) - Tiny Tenants
motionEmotion TV

Uploaded on Jan 11, 2012


  leptoglossus occidentalis-cimice americana delle conifere
TheCrot2009 - Krotalo

Uploaded on Dec 5, 2011

Originaria degli Stati Uniti occidentali (California, Oregon e Nevada) ove trova il suo habitat naturale, le foreste di conifere, la specie è stata importata anche in Italia.
La cimice dei pini (Leptoglossus occidentalis Heidemann, 1910) è un insetto fitofago della famiglia dei Coreidi (Rhynchota Heteroptera).

Arriva in Italia probabilmente con l'importazione di legname. Nel 1999 è segnalato in Veneto. Quindi lo si trova anche in Lombardia, Friuli-Venezia Giulia, Trentino, Sicilia ed Emilia-Romagna. Nell'autunno 2006 è stato avvistato anche in Umbria. In Sardegna è ormai diffuso in tutta l'isola[1].
La sua presenza in ambienti meno ricchi di conifere non deve meravigliare in quanto l'insetto vive anche a spese del pistacchio.

Google Translate: Native to the western United States (California, Oregon and Nevada) where it finds its natural habitat, coniferous forests, the species was imported in Italy. The bug pines (Leptoglossus occidentalis Heidemann, 1910) is an insect pest of the family of Coreidi (Hemiptera Heteroptera).She arrives in Italy probably by importing timber. In 1999, it reported in Veneto. So it is also found in Lombardy, Friuli-Venezia Giulia, Trentino, Sicily and Emilia-Romagna. In autumn 2006 was spotted in Umbria. Sardinia is now widespread throughout the island. [1] Its presence in some less rich conifer is not surprising because the insect lives even at the expense of the pistachio.


  Western Conifer Seed Bug (Leptoglossus occidentalis)
Fyn Kynd

Published on Jan 31, 2013




Visitor Sightings

Report a sighting of this insect.

  This button not working for you?
Simply email us at info@MinnesotaSeasons.com.
Be sure to include a location.

Location: Alexandria MN Douglas CO

western conifer seed bug


Location: Morrison County, MN


  Alfredo Colon
October 2017

Location: Woodbury, MN

western conifer seed bug


Location: Mound MN

western conifer seed bug

MinnesotaSeasons.com Sightings






Created: 10/29/2015

Last Updated:

About Us | Privacy Policy | Contact Us | © MinnesotaSeasons.com. All rights reserved.