Circulifer tenellus (Baker 1896a: 24 )Membracoidea : Cicadellidae
|Diseases Transmitted||Pathogen Type|
|[beet]curly top virus (Phytoplasma) (Virus)||Virus|
|Tomato big bud 16SrVI-A||Phytoplasma|
|Crops Affected by Circulifer tenellus (Baker 1896a: 24 )|
This species is a vector of curly top virus and sowbane mosaic virus. It was the first reported leafhopper vector of a plant virus in North America. Ball in 1907 and 1909 (24, 27) was first to report the association of the beet leafhopper with “curly leaf” disease of sugarbeets, but Shaw in 1910 (716, 717) reported the first evidence of transmission of the virus by the insect. Transmission of the virus has since been confirmed by numerous investigators, and a long list of host plants susceptible to the disease has been recorded.
In 1910, Shaw (716) demonstrated transmission with single leafhoppers feeding for a short time on diseased sugarbeets. Smith and Boncquet in 1916 (745) and Boncquet and Hartung in 1915 (103) tested leafhoppers collected from wild plants and placed on healthy sugarbeet seedlings, which did not become infected. However, part of the populations was fed on diseased plants from 3 to 7 days and transferred to healthy plants, which came down with - the disease. Smith and Boncquet in 1916 (745) confirmed these results and found that 3 hours’ feeding on diseased plants produced viruliferous leafhoppers. They reported an incubation period of 1 to 2 days before the leafhopper transmitted the causative organism.
Ball in 1917 (29) was convinced that the disease was caused by the punctures of the leafhopper while feeding on plants. Transmission of the virus from naturally infective leafhoppers was demonstrated by Severin in 1919 (684), and he also reported an incubation period of a few hours in the insect before transmission was effected. Multiplication of the virus in the insect’s body was first suggested by Carsner and Stahl in 1924 (122) when they found that longer feeding periods on diseased plants produced more infective leafhoppers.
Further studies on the mode of transmission by the beet leafhopper were reported by Severin 1931 (689). Percent transmission increased from 2.4 after feeding 20 minutes on test plants to 33.3 after feeding 4 hours. An increase in the number of leafhoppers per test gave an increase in percent transmission. Single insects were able to transmit after an incubation period of 7 hours. In 1938, Bennett and Wallace (67) reported a minimum incubation period of 4 hours. Fasting leafhoppers for short or very long periods prior to testing decreased transmission efficiency and percentage of transmission.
There was no evidence of multiplication of the virus in the insect. In 1936, Freitag (281) presented negative evidence of multiplication of the virus in the insect by demonstrating that certain adults lost their ability to transmit later in adult life after receiving a “low charge” of the Virus as young adults. Others retained ability to produce infections, but only at great intervals. Virus retention in some adults was as long as 151 to 180 days.
Several strains of curly top virus have been reported that varied in their symptomatology from mild to severe (Giddings 1950 , Menzies and Giddings 1953 ; and Bennett 1955  1962 ). Some strains would not cross-protect, indicating that they may be different but closely related viruses.
Transmission of the curly top virus from Turkey was reported in 1957 and 1958 by Bennett and Tanrisever (65, 66), and thus similar relationships of the virus were established between Turkey and North America. This is additional evidence that the origin of the virus and leafhopper is in the Mediterranean region.
Transmission of sowbane mosaic virus was reported by Bennett and Costa in 1961 (63). After fasting the leafhoppers for 8 hours, four successive transfers at 2-hour intervals were obtained. Little infection was obtained after the fourth feeding period, indicating the leafhoppers lost their ability to transmit the virus; Sowbane plants were infected from contaminated mouth parts, since the leafhoppers were infected only for 8 hours following an initial 2-hour acquisition feeding period.
This species is the only known vector of curly top virus in North America and is one of the most important leafhopper vectors of plant viruses. Transmission of sowbane mosaic virus is of academic importance.
Small, linear species. male 3.10—3.20 mm., female 3.40—3.60 mm.
General color light tan, immaculate. Crown, pronotum, and scutellum light tan; elytra light tan, hyaline.
Pygofer in lateral aspect about 1½ times as long as wide, caudoventral margin produced posteriorly to small lobe, small spine arising from apex of caudoventral margin, projecting dorsad; aedeagus in ventral aspect with pair of terminal semicircular processes; gonopore terminal on apex of each process; style in dorsal aspect with apices broad and curved laterally; female seventh sternum in ventral aspect with medium excavation on caudal margin.
species is similar to
in general habitus and genital characteristics. It is most easily separated by the male plates, which together are truncate apically. Further characterization of the genitalia of
was presented by Oman in (1948)
and Young and Frazier (1954)
|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.|