Hero Image

A Field Key to Lygus Species of the San Joaquin Valley

The Issue

Lygus bugs are a key economic pest of many crops in California, including field crops, vegetables, nuts and fruits. There are 43 species of Lygus bugs in the world, 34 of which are known to exist in North America. Three species are reportedly found in the central San Joaquin Valley of California: Lygus hesperus, Lygus elisus, and Lygus lineolaris. To date, there has been no simple method to distinguish among these three species. Pest management strategies must begin with correct identification.

What Has ANR Done?

A team of UC DANR scientists collaborated on a pictorial key to the three species of Lygus bugs commonly found in agronomic crops of the central San Joaquin Valley. UCCE Fresno County Farm Advisor Shannon Mueller worked with UC Davis Entomologist Charlie Summers and UC IPM Entomologist Pete Goodell to improve her understanding of Lygus bug ecology and identification.

One outcome of her work was development of a field key with photographs showing significant differences among the species. The pictorial key is based on characteristics that are easy to observe and is illustrated to highlight important morphological features. The key also contains a detailed description of Lygus as well as pictures of other similar-appearing plant bugs, which helps prevent misindentification. A "quick guide" to identifying the species can be removed from the publication and used independently once the user is familiar with key distinguishing features. Although primarily developed for use in field crops, the key can also be used to identify Lygus found in other cropping systems.

These two ANR publications, "A Field Key to the Most Common Lygus Species Found in Agronomic Crops of the Central San Joaquin Valley of California" and "Key Features of Common Lygus Species in the Central San Joaquin Valley", are available on the web at Lygus.uckac.edu or through the ANR Publications E-catalog http://anrcatalog.ucdavis.edu/. The ANR Lygus Management Workgroup supported this work and has provided funds to print 500 copies.

The Payoff

Accurate identification of Lygus improves pest management

Growers, pest control advisers and researchers now have a simple tool available to allow them to identify species of an important economic pest. Because proper identification of a pest organism is the first step in IPM, a detailed key to the Lygus species and its companion "quick guide" are improving pest management strategies and effectiveness. In addition, the ability to correctly identify various Lygus species can improve interpretation of research results or enhance progress in areas such as biological control and assessment of economic damage.

Clientele Testimonial

"The glossy key and accompanying manuscript make for an excellent guide for distinguishing among the various Lygus species in the San Joaquin Valley and will be beneficial to scientists and PCAs."


Supporting Unit: Fresno County and Kearney Agricultural Center

Shannon C. Mueller, UCCE Agronomy Farm Advisor, 1720 S. Maple Avenue, Fresno, CA 93702, (559)456-7261

Charlie Summers & Peter Goodell, Kearney Agricultural Center, (559) 646-6500