weevil

(Lixus terminalis)

               
Conservation Status

IUCN Red List

not listed

weevil (Lixus terminalis)

 

NatureServe

NNR - Unranked

Minnesota

not listed

Occurrence

 

Flight/Season

One generation per year: April through August

Habitat/Hosts

Unknown

Size

Total Length: 5 16 to 7 16

          Photo by Alfredo Colon

Identification

Lixus terminalis is a medium-sized true weevil. It occurs across North America. The body is elongated, cylindrical, smooth, and 5 16 to 7 16 (8 to 11 mm) long. The overall color is walnut brown, at least in museum specimens.

The thorax is composed of three segments. The first segment (prothorax) is large and prominent and appears to be the entire thorax. It is covered by a saddle-shaped plate (pronotum). The pronotum is longer than wide, has straight sides, is rounded vertically, and is depressed in the middle. It is slightly wider at the base than the wings at their base. The base is straight near the sides and has a small triangular projection (lobe) in the middle. The surface is pitted with scattered large and small punctures.

There are two pairs of wings, a membranous inner pair and a hardened outer pair (elytra). The elytra are attached to the second thoracic segment (mesothorax). They cover the mesothorax, the third thoracic segment (metathorax), and completely cover the abdomen. They are wider than the pronotum, oblong egg-shaped, narrowed toward the tips, moderately convex, longitudinally grooved, and pitted. There is a deep depression at the base in the middle that joins the similar depression on the pronotum. The tips of the elytra are rounded and distinctly separated. The pronotum and elytra are covered with short, fine, gray hairs. These hairs wear off irregularly, becoming patchy on older individuals.

The head is greatly elongated between the eyes and the mouth parts forming a conspicuous snout (rostrum). The rostrum is relatively thickened, enlarged toward the tip, and very long, as long as the prothorax. It is projected forward and slightly bent downward. Antennae are inserted one fifth of the way from the tip. The antennae are short, slender, and elbowed. The last 3 segments are expanded and form a club. There are seven jointed segments between the base and the club. The first two segments are long, the second much longer than the first. The third through seventh segments are short. The first antennal segment (joint) beyond the base is thicker than the second joint. The second joint is as long or longer than the next two joints combined.

The third leg segment (femur) is slightly club-shaped.

 
Similar
Species

Overwintering adults become active in April. After mating, the female punctures the stem or crown of a host plant with her snout and feeds, creating a cavity. She then inserts a single egg about deep into the cavity. The egg hatches in 7 to 10 days. The larva burrows into the stalk or roots creating a gallery and pupates within the gallery. Adults overwinter in leaf litter.


Larval Food

Host plant stalks.

Larvae have been reared on the laboratory on water smartweed and Pennsylvania smartweed. What the hosts are in nature is unknown.

 
Adult Food

Host plant soft tissues

 
Life Cycle

 

 
Behavior

 


Distribution Distribution Map  

Sources: 24, 27, 29, 30.


Comments

No Common Name
This species has no common name. One of the common names of the family Curculionidae is weevils, and is applied here for the sake of convenience.


Taxonomy

Order:

Coleoptera (beetles)

 

Suborder:

Polyphaga (water, rove, scarab, long-horned, leaf and snout beetles)

 

Infraorder:

Cucujiformia

 

Superfamily:

Curculionoidea (snout and bark beetles)

 

Family:

Curculionidae (snout beetles, weevils)

 

Subfamily:

Lixinae

 

Tribe:

Cleonini

 
Synonyms

Lixus blakeae

 
Common
Names

no common name


 

 

 

 

 

Glossary

Elytra

The hardened forewings on an insect used to protect the fragile hindwings, which are used for flying, in beetles and true bugs.

 

Femur

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

 

Pronotum

The saddle-shaped, exoskeletal plate on the upper side of the first segment of the thorax of an insect.

 

Prothorax

The first (forward) segment of the thorax on an insect, bearing the first pair of legs but not wings.

 

Rostrum

The stiff, beak-like projection of the carapace or prolongation of the head of an insect, crustacean, or cetacean.

 

 

 

 

 

       

Visitor Photos

   
Share your photo of this insect.

Alfredo Colon


  weevil (Lixus terminalis)    

       
       
       

MinnesotaSeasons.com Photos

   
       
       
       

 

Camera

     

Slideshows

   
     
     
     
     

 

slideshow

     

Visitor Videos

   
Share your video of this insect.

     
     

Other Videos

 
     
     
     

 

Camcorder

         

Visitor Sightings

   
Report a sighting of this insect.

Alfredo Colon
6/21/2018

Location: Woodbury, MN

weevil (Lixus terminalis)


     
     
 

MinnesotaSeasons.com Sightings

   

 


 

 

Binoculars

Last Updated:

About Us | Privacy Policy | Contact Us | © 2019 MinnesotaSeasons.com. All rights reserved.