Forages: Alfalfa Snout Beetle (Otiorhynchus ligustici)

Excerpt from Chapter 3, Field Crop Protection Guide, Order this publication

Table of Contents

1. Description
2. Integrated Pest Management Options
3. Related links...

Description

The adult is a flightless, dark grey weevil approximately 12 mm in length. Larvae are small, white and legless with a light-reddish-brown head and can be found in the soil, feeding on or in the roots. The alfalfa snout beetle (ASB) is an introduced insect in North America. The insect was detected initially in New York state and has been a pest of concern there since 1933. The ASB has spread mainly in a northeasterly direction during last 60 years in New York state. Two localized infestations 50 miles apart exist in Ontario. One is on Wolfe Island where the initial find was made in 1967. The second infestation is on the mainland near Prescott and Brockville in Grenville and Leeds counties, an area consisting of about 14 km2. Serious damage has been found on several farms in the area.

Image 1. Adult of alfalfa snout beetle.

Image 2. Larva of alfalfa snout beetle.

Image 3. Aboveground symptoms of alfalfa in late summer due to the damage by snout beetle.

Image 4. Damage of alfalfa taproot by snout beetle.

Image 5. Dead area in alfalfa field caused by snout beetle.

Integrated Pest Management Options

Related links...

• Agronomy Guide for Field Crops - Publication 811
  • Forages: Alfalfa Snout Beetle
• Alfalfa Snout Beetle Infosheet
• Insects
• Forages