Asparagus beetle on asparagus head

Asparagus spear infested with asparagus beetle.

Updated: February 20, 2023

Appearance

  • Common or striped asparagus beetle: This is the more common beetle feeding on asparagus spears and ferns. The adults have colorful orange and blue-black markings.
  • Spotted asparagus beetle: This beetle has orange wing covers with 12 spots. Mainly a pest of the older asparagus cultivars that produce berries (newer all-male hybrids produce no fruit) because the larvae feed on the berries.
Adult common asparagus beetle
Adult common asparagus beetle
Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org
Asparagus beetle larvae on fern
Asparagus beetle larvae on fern
Adult spotted asparagus beetle. Credit:Whitney Cranshaw, Colorado State University, Bugwood.org
Adult spotted asparagus beetle. Credit:Whitney Cranshaw, Colorado State University, Bugwood.org

Life cycle and habits

  • The ¼ inch long adults emerge from overwintering sites in and around the garden in early spring and feed on emerging spears.
  • There are multiple generations each year and populations can reach high levels leading to severe loss of spears and foliage.

Signs and symptoms

  • After mating, very small black eggs are inserted into the spears and the small gray larvae that emerge begin feeding on spears. 
Asparagus beetle eggs on spear
Asparagus beetle eggs on spear
Asparagus beetle feeding damage and eggs
Asparagus beetle feeding damage and eggs

Prevention and control

  • Handpick adults and larvae or control with a botanical insecticide (neem, pyrethrum).
  • Cut spears quickly after they reach eating size and clean up all plant debris and weeds at the end of the season to remove over-wintering sites.

Related information

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