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Species Account


CAS; Male; Det. Nielson; 'Laguna Mt. Cal. US'; 6000ft
E001771

CAS; Male; Det. Nielson; 'Laguna Mt. Cal. US'; 6000ft
E001772

CAS; Male; Det. Nielson; 'San Diego Co. Cal. US'
E001773

USNM; Paratype; Male; Desig. Beamer; 'Redland,Cal.'
E002718

USNM; Female; Det. Beamer
E002719

CAS; Male; Det. Nielson; 'Laguna Mt. Cal. US'; 6000ft
NMW Image No. E001771

Cuerna occidentalis Oman & Beamer 1944a: 119

Membracoidea : Cicadellidae
Diseases Transmitted

Distribution Map
(simplified continental distribution)
Geographical Distribution:
North America

Recorded Distribution(s):
United States: California (Nielson 1965a)

It is known only from the southern half of California. In 1965, Nielson (563) examined specimens from Alpine, Bbythe, Campo, Cbaremont, Cucamonga, Davis Creek, Green Valley, He-met, Idyllwild, Jacumba, Laguna Mountains, Mill Valley, Mint Canyon, Pasadena, Pine Hills, Pine Meadows, Riverside, San Diego, San Jacinto Mountains, and Santa Maria. (Nielson, 1968)

Cuerna occidentalis Oman & Beamer 1944a: 119
Diseases Transmitted Pathogen Type
Crops Affected by Cuerna occidentalis Oman & Beamer 1944a: 119
Rice Citrus Carrot
Barley Apple Tomato
Maize (Corn) Pear Potato
Sugarcane Elm Strawberry
Wheat Palms Rubus
Sorghum Grapevine Papaya
Other (grasses/cereals) Ornamentals Peach

This species is a vector of Pierce’s disease virus of grape in California. Frazier (273) first reported this species as a vector of this virus in 1944. Later, in 1952 Freitag et al. (287) confirmed these results and showed that the species was an efficient vector by infecting 63 percent of plants tested. The virus was transmitted from diseased grape to healthy grape and alfalfa, and from diseased alfalfa to healthy grape and alfalfa. The high percentage of transmission was attributed to long survival of the vector on test plants. Natural infectivity was demonstrated by testing field-collected specimens (Freitag and Frazier 1954) [286]. Twenty-eight percent of seven individuals tested were infective.
(Nielson 1968)

This species is considered of some importance in the natural spread of Pierce’s disease virus of grape.


(Nielson 1968)

Identification Plates
Cuerna occidentalis


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Plate 1
Species Description

Length:
Medium size, slender species.male 5.80—6.60 mm., female 6.60—7.40 mm.

Colour:
General colour yellowish gray to black with prominent yellow or ivory band running laterally from anterior margin of head to eighth tergum; head, pronotum, scutellum, and elytra with numerous fine yellow and black markings.

Genitalia:
Pygofer in lateral aspect about 1½ times as long as wide, can-dab margin convex; aedeagus in lateral aspect excluding atrial processes about 1½ times longer than wide, shaft very short, curved posterodorsad with prominent tooth on each side of middle in caudal aspect; lateral atrial processes bong, about 1½ times longer than caudal atrial processes, basal two-thirds straight, apical one-third curved posterodorsad, projecting dorsad beyond apex of aedeagal shaft, broad basally, attenuated apically; caudal atrial processes short, narrower than lateral atrial processes, nearby straight, projecting dorsad to but not extending beyond apex of aedeagal shaft, curved slightly laterad in caudal aspect; female eighth sternum in dorsal aspect with two weakly sclerotized, elongate, oval-shaped, symmetrical plates about half as long as seventh tergum and broadly separated from each other; each plate projecting posterolaterad, sometimes nearly laterad, lateral sides nearly parallel, apex convex.

Species Diagnosis

This species, similar to yuccae in general habitus, can be distinguished by the aedeagus with lateral and caudal atrial processes straight and projecting dorsad in lateral aspect.

(Nielson 1968)

Ecology

Host Plant Activity Period (Months) Dormancy Generations
- -
Eggs -
Nymphs -
Adult -
One per year -
Continuous -
Variable -
Cuerna occidentalis Oman & Beamer 1944a: 119

Higher taxonomy

Kingdom Phylum Class Order Superfamily Family
Animalia Arthropoda Insecta Hemiptera
Suborder: Auchenorrhyncha
Infraorder: Cicadamorpha
Membracoidea Cicadellidae
Subfamily: Cicadellinae
Cuerna occidentalis Oman & Beamer 1944a: 119
References
Nielson, M. W. 1968b. The leafhopper vectors of phytopathogenic viruses (Homoptera, Cicadellidae). Taxonomy, biology and virus transmission. United States Department of Agriculture Technical Bulletin . 1382 386 pp.
Record last updated - 25/09/2019