University of Maryland Extension

Asparagus Beetles - Vegetables

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Damage to asparagus spears and feeding damage on the ferns is a sign of an asparagus beetle infestation.

asparagus beetles on spear
Asparagus spear infested with asparagus beetle

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.

striped and spotted asparagus beetle adults
Striped cucumber beetle and spotted cucumber
beetle adults 
Photo: Whitney Cranshaw, Colorado State University, Bugwood.org

beetle larvae on asparagus ferns 
Asparagus beetle larvae on fern

Life Cycle/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/Symptoms

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

asparagus beetle eggs damaging spear
Asparagus beetle eggs on spear

asparagus beetle eggs
Asparagus beetle feeding damage and eggs

Prevention/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.

 

 

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