Hybrids OfNephotettix impicticepsIshihara andN. apicalis(Motsch.) and their ability to transmit the tungro virus Of rice

Abstract

Rice tungo virus is tranmitted by Nephotettix impicticeps Ishihara but not by the closely related N. apicalis (Motsch.). Hybrids have been obtained from crosses between these two species. The morphological characteristics of the hybrids were not identical with either parent in respect to the marking on the abdomen of the nymphs, the submarginal black band on the vertex of the adults, or the number of teeth on the ventral surface of the aedeagus of the male genitalia. However, more than 10 per cent. of them, regardless of stage of development or sex, were able to transmit the tungo virus, indicating that the transmissive ability is inherited even in an interspecific cross. The virus seems to be nonpersistent in the hybrids as it is in N. impicticeps.

Probable natural hybrids of Nephotettix virescens (Distant) and N. nigropictus (Stal) (Hemiptera: Cicadellidae) from Sabah, Malaysia

“…In the present material, as was observed by Ling (1968), all the parts of genitalia, the pygofer, subgenital plates, parameres and aedeagus, do not show any striking differences from those of virescens or nigropictus so far as their shape is concerned. The main difference was found in the number of spines on the pygofer and the aedeagal shaft.…”

“…It is partially developed and in most specimens is represented by somewhat crescent-shaped patch behind each ocellus. Ling (1968) on male hybrids of virescens and nigropictus in the laboratory but did not describe the females. In the present material, some females have a well-developed submarginal black band on the vertex and in others it either fades in the centre or becomes completely broken.…”

“…The number of spines on the pygofer was very variable and in most cases varied between the left and right lobes of the same pygofer (Table I and Figures). Ling (1968) did not study this character. The number varied from 2 to 7 (Fig.…”

“…nigropictus (Stal) (15 specimens), but there was a third category of 30 specimens that were intermediate between these two species and showing variations in certain characters. Ling (1968) has described the morphological characters of hybrids of N. virescens and N. nigropictus bred in the laboratory. He showed that the hybrids could transmit rice tungro virus, even though one of the parents (N. nigropictus) is not a vector of this disease.…”

Biosystematics of rice brown planthopper and rice green leafhoppers

“…Though they are usually clearly separable on the basis of colour patterns, in fields sometimes morphologically intermediate individuals ate found. Hybrids of these two species were produced in the laboratory which showed intermediate morphological characters (Ling 1968;Inoue 1983). …”