Lagocheirus araneiformis insulorum (Linnaeus, 1767) (Dillon, 1957)

Cassava cerambicide

General

• Phytophagous beetle insect of the Cerambycidae family.
• Native to the Antilles (Guadeloupe, Martinique) and Guyana, it has been introduced into New Caledonia.
• Mainly affects cassava stems.
• No observation of the adult in the open field, only the larvae are visible in the attacked feet. 

• Sensitive botanical family (s)

• Affected production areas :

• Organs attacked

 Symptoms, damage

• Symptoms : 
  • Only larvae and pupae cause damage.
  • Presence of galleries in the stems caused by the activity of xylophagous larvae feeding on the wood (figures 1 to 3).
  • Leaf wilting of parasitized twigs, sometimes even dieback of entire plants.
  • Noticeable impact on yield in the event of heavy infestation.

• Signs : Presence of larvae in the stems (Figures 2 to 4).
• Possible confusion :

 Biology

•  Development cycle : includes 3 stages of development: larva, pupa and adult.
  • The larvae and pupae develop in the wood. The larvae are fleshy and cylindrical in shape (Figures 2-4). They are white to slightly ivory in color.
  • pupation, which lasts about a month, usually takes place under the stumps.
  • Emerging adults can remain in their pupation sites for several months, the time necessary for their integuments to harden. Then thereafter they have a rather aerial life. They measure between 18 and 28mm in length, and are characterized by a robust body made up of different reliefs. Gray-brown in color, their antennae are very developed, even longer than their body. They feed mainly on pollen and wood debris, some can consume and live on the reserves accumulated during the larval stage. 

 Protection 

• No effective protection methods have been reported for this pest.
• Eliminate and destroy affected twigs or plants during and at the end of cultivation.