Argentine Stem Weevil

Common Name

Argentine Stem Weevil

Seasons of Activity

All year round

Areas of Plant Affected

Foliage

Scientific Name

Listronotus bonariensis

Key Distinguishing Feature

Water stressed appearance in late spring/summer.

The adult Argentine Stem Weevil, which are dark grey to black in colour and have a distinctive protruding snout, lay eggs within the turfgrass canopy under the sheath of the leaf blades. Once the eggs hatch, the larvae (first instar) begins feeding on the inside of the plant stems, until the 2nd or 3rd instar, where they then burrow out of the plant and fall to the ground.

At this stage they then feed on the plants crowns and growing points causing significant damage. The older instars live in the thatch and feed on the roots. After the fifth instar is reached the larva pupates within the upper soil profile and the adult soon emerges. The cycle then begins once again with the adults laying eggs from July. The larvae are more destructive than the adult Argentine Stem Weevil.

Key Products for Control:

Acelepryn Liquid - 15mL/100sqm in 6-10Ltrs water, then water into soil.

Acelepryn GR - 1.5Kg/100sqm then water into soil.

Monarch G - 0.6-1.5kg/100sqm

Rumbler - 12-44mL/100sqm