Psammotettix alienus (Dahlbom 1850a: 187 )Membracoidea : Cicadellidae
|Diseases Transmitted||Pathogen Type|
|wheat dwarf [monogemini]virus 16Sr||Virus|
|Crops Affected by Psammotettix alienus (Dahlbom 1850a: 187 )|
This species is a vector of wheat dwarf virus in Czechoslovakia. Transmission of the virus was first reported by Vacke in 1961 (805) when he was able to obtain both natural and experimental transmission of the virus from diseased wheat to healthy wheat and from diseased barley to healthy barley. Both nymphs and adults were able to transmit the virus, but with a higher degree of efficiency by nymphs. From 73 to 82 percent of the plants were infected by nymphs.
In 1962, Vacke (806) determined that the incubation period of the virus in the vector varied from 1 to 4 days. There was evidence that the minimum incubation period was less than 1 day. The virus was a semipersistent type as evidenced by the inability of the insects to retain it for life. The maximum retention period was 80 days. Variation in transmissibility of the virus by individual leafhoppers was noted, and old individual adults were less efficient than nymphs or young adults. Among first-instar nymphs 97 percent of the population transmitted the virus, third instar 88 percent, fifth instar 91 percent, 1- to 4-day-old adults 84 percent, 10- to 13-day-old adults 66 percent, and 23- to 26-day old adults 58 percent. Studies failed to demonstrate transovarial transmission of the virus.
This species is an important vector in the natural spread of this virus in Czechoslovakia.
Small, linear species. Length of male 3.80—4.10 mm., female 4. 10—4.30 mm.
General color tannish brown. Crown tan with bight-brown patches on disk; pronotum tannish brown; ebytra tan, cells bordered with brown, Veins ivory or tan.
Pygofer in lateral aspect slightly longer than wide, caudal margin broadly convex; aedeagus in lateral aspect tubelike, curved; gonopore subapical on ventral surface of shaft; style in dorsal aspect with apices short, curved laterally, expanded apically; female seventh sternum in ventral aspect with caudal margin truncate (fig. 105).
This species is closely related to striatus and difficult to separate on the basis of general habitus and male genital characteristics. I have followed Ribaut (643) in his 1952 interpretation of the species, which distinguished alienus from striatus by the aedeagus, which is truncate apically in lateral aspect and emarginate apicaily in ventral aspect.
|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.|