Friscanus friscanus (Ball)

Description & Identification

Small to medium size species; male slender, macropterous; female robust, submacropterous. male 3.70—3.80 mm., female 5.40—5.80 mm. (Nielson, 1968)General colour light tan. Crown and pronotum of male tan with pair of distinct sinuate longitudinal markings, female unmarked; elytra light yellowish tan.(Nielson, 1968)Pygofer in lateral aspect about as long as wide, ventral margin distinctly notched near middle, caudal margin with long, narrow, prominent spine arising from caudoventral margin and projecting dorsally; aedeagus in lateral aspect broad basally, narrow, tubelike, and curved laterally at apical half; gonopore subapical on ventral surface of shaft; style in dorsal aspect with apex narrow and curved laterally; female seventh sternum in ventral aspect with caudal margin nearly truncate. (Nielson, 1968)This is the only species of Friscanus that is a vector. DeLong and Severin (1949) illustrated the genitalia and Severin (1949) presented colored reproductions of the adults.(Nielson 1968)

Biology & Ecology

The biology of this species is not well known. The principal host is Lupinus arboreus Sims. In 1938, Oman (582) collected numerous nymphs and adults on this plant in the area around San Francisco. DeLong and Severin (197) reported collections from the same host in San Francisco County in 1949 and in canyons and exposed slopes on the Montara Mountains in San Mateo County during May and June. The adults moved to other plants and were occasionally taken on California sagebrush (Artemisia californica Less.). Severin (706) reported low longevity of adults in 1949, 2 to 6 days on grape and 3 to 12 days on alfalfa. (Nielson, 1968)

Classification

Order

Hemiptera

Suborder

Auchenorrhyncha

Family

Cicadellidae

Subfamily

Errhorominae

Tribe

-

Genus

Friscanus

Species

friscanus

Authorship

(Ball)

Synonymy

Errhomenellus friscanus Ball, 1909
Memnonia simplex Van Duzee, 1917

Additional Images

Images provided by GBIF data providers. We cannot verify that identifications are correct.

Worldwide Distribution

It is restricted to the San Francisco Bay area of California and is not known to occur outside of this State. (Nielson, 1968)

Vector Status

Economic Crops

This species is a vector of Pierce’s disease virus of grape in California. It was first reported as a vector of this virus by Frazier and Freitag (275) in 1946. Transmission of the virus from diseased alfalfa to healthy grape and alfalfa was accomplished, but the insect was unable to infect grape and alfalfa from diseased grape. Twenty-one percent of the plants tested were infected. Both grape and alfalfa proved to be poor hosts for feeding. Severin in 1949 (706) confirmed transmission, but reported this species as an inefficient vector of the virus owing to low longevity of adults on grape and alfalfa. The latent period of the virus varied from 1 to 6 days. In 1954, Freitag and Frazier (286) found 14.8 percent of the lots collected on Lupinus to be naturally infective.(Nielson 1968)This species is not considered an important vector of Pierce’s disease virus of grape.(Nielson 1968)

Plant Diseases