Dalbulus maidis (DeLong [In Wolcott] 1923b: 265)Membracoidea : Cicadellidae
|Diseases Transmitted||Pathogen Type|
|Maize bushy stunt phytoplasma 16SrI-B||Phytoplasma|
|Crops Affected by Dalbulus maidis (DeLong [In Wolcott] 1923b: 265)|
This species is a vector of corn stunt virus in the Southwestern United States, Mexico, El Salvador, and Surinam. Kunkel in 1946 (430) was first to report transmission by the vector under the name “Baldulus maidis.” By 1948 he (431) confirmed transmission by transferring a colony of 50 leafhoppers, which had been reared on virus-diseased plants, to 170 healthy corn plants. After they fed for 24 days, 169 plants developed stunt disease. The incubation period of the virus in the vector varied from 14 to 32 days. The minimum incubation period was 14 days, which at that time was the longest recorded for a vector species. The minimum incubation period in corn was 26 days. Retention of the virus was as long as 88 days.
In, 1955 Maramorosch (481) transmitted two strains of the virus in Mexico called “Rio Grande” and “Mesa Central” by this species. By 1958, he (483) demonstrated later that the insect was able to transmit either strain alone or both simultaneously after short acquisition feeding periods. He demonstrated unilateral cross protection between the two strains using long acquisition feeding periods, up to 14 days. When Mesa Central strain was acquired first, it transmitted first and was followed by transmission of Rio Grande strain. When Rio Grande strain was acquired first, the insect became immune to infection by the Mesa Central strain.
This species is the most important vector in the spread of this virus in the United States, Mexico, and Central America.
Small, linear species. Length of male 3.50—4.00 mm., female 4.00—4.10 mm.
General color yellowish white. Crown with two distinct round black spots; pronotum yellowish; elytrahyaline.
Pygofer in lateral aspect about twice as long as wide, caudal margin obliquely truncate; aedeagus in lateral aspect short, broadly tubelike, with pair of hooked processes on distal end in ventral aspect; gonopore terminal; style in dorsal aspect simple, apices with lateral apical projection; female seventh sternum in ventral aspect with lateral margins distinctly convex, caudal margin distinctly concave (fig. 68).
From elimatus, to which it is similar in general habitus, maidis can be separated by the pygofer, which lacks a sclerotized ventral margin, by the distinctive aedeagus, and by the female seventh sternum with a concave caudal margin. I do not believe that this species has been properly placed generically, but I will reserve final judgment until after all species assigned to the genera Dalbulus and Baldulus have been thoroughly studied.
|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.|