The Asparagus Beetle: Organic Control Tips

If your asparagus patch looks weak and unhealthy, chances are the asparagus beetle has struck again. Protect your crop with organic pest control methods, such as attracting beneficial insects and spraying neem. Plus, learn to recognize asparagus beetle damage before it's too late.


| January 18, 2013



Asparagus Beetle

Asparagus beetles overwinter in plant debris, so removing fronds in winter will reduce their numbers.


Illustration By Keith Ward

This article is part of our Organic Pest Control Series, which includes articles on attracting beneficial insects, controlling specific garden pests, and using organic pesticides.   

The most common of asparagus pests, asparagus beetles weaken plants when fed upon by adults and larvae. Organic methods of asparagus beetle control include handpicking, and gathering up and composting old asparagus foliage and berries. Originally from Europe, asparagus beetles are now found throughout North America, wherever asparagus is grown.

What Are Asparagus Beetles? 

The common asparagus beetle (Crioceris asparagi) is the most prevalent asparagus pest that damages young asparagus spears. Overwintering as an adult, this slender, elongated beetle bears four white or yellowish spots on its wings, is reddish underneath and on the wing edges, and has a dark-red thorax. It is 1/4 to 1/3 inch long. 

The spotted asparagus beetle (Crioceris duodecimpunctata) is also quite colorful. In the western United States, the spotted asparagus beetle is bright pumpkin orange with tiny black dots on its wings. In other areas, the background color of spotted asparagus beetles can be red to dark red. The antennae of both asparagus pests measure about half its body length.

Asparagus Beetle Damage 

In early spring, just as asparagus spears are breaking the surface, adult asparagus beetles emerge after overwintering in plant debris. They begin feeding on the earliest spears, causing them to crook like a shepherd’s crook. Soon after mating, the females lay tiny, dark, elongated eggs on the little spears and new foliage, which stick out at right angles. Adults dine on the main spears, while the grayish-green, soft-bodied larvae feed on spears and foliage. Indentations caused by the feeding are brown in color and will decrease the vigor and size of affected spears. Severe feeding reduces the vigor of the asparagus plants.

Adult spotted asparagus beetles emerge one to three weeks later than common asparagus beetles. Late in the spring, these asparagus pests may be found all over asparagus plants, but usually they do only minor damage. The egg-laying cycle is timed to coincide with the formation of asparagus berries. Adults lay eggs on or near berries, the larvae bore inside to feed, and then drop to the ground to pupate into adults. The larvae feed only within the berries. Spotted asparagus beetle larvae are yellowish with black heads and legs.

carmeno
7/21/2016 7:08:17 PM

The best way I found to deal with asparagus beetles is to plant either tomatillos or ground cherries close by. In my garden they will go for those two and forget about the asparagus. I found out by chance. I am able to harvest asparagus and zero ground cherries. The tomatillos' production is reduced.






mother earth news fair

MOTHER EARTH NEWS FAIR

Oct. 21-22, 2017
Topeka, KS.

More than 150 workshops, great deals from more than 200 exhibitors, off-stage demos, inspirational keynotes, and great food!

LEARN MORE