Large numbers of the small brown planthopper Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae) occur in temperate regions, causing severe losses in rice, wheat, and other economically important crops. The planthoppers enter diapause in the third- or fourth-instar nymph stage, induced by short photoperiods and low temperatures. To investigate the geographic variation in L. striatellus dia...

Wolbachia, a bacterial endosymbiote of arthropods, causes cytoplasmic incompatibility (CI) in many insect species. CI traits were studied in two planthopper species, Laodelphax striatellus and Sogatella furcifera, and Wolbachia densities in these planthopper species were calculated by quantitative PCR methods. The CI level of L. striatellus was quite high and even aged males strongly caused CI....

When adult males of the smaller brown planthopper, Laodelphax striatellus were fed on 2% crude rice (leaf and stem) extract containing 15% sucrose there were characteristic stylet sheaths deposited on parafilm membrane. Further bioassays with the butanol-soluble fr. of the extract revealed that it is highly effective for the insects. When the butanol fr. was charged on an ODS open column and el...

Virus-vector relationships can be complex and diverse as a result of long-term coevolution. Understanding these interactions is crucial for disease and vector management. Rice stripe virus (RSV) is known to be transovarially transmitted within its vector, Laodelphax striatellus, and causes serious rice stripe disease. In RSV-infected L. striatellus, we found contrasting changes in vector fecund...

Insect vitellogenin (Vg) has been considered to be synthesized in the fat body. Here, we found that abundant Vg protein is synthesized in Laodelphax striatellus hemocytes as well. We also determined that only the hemocyte-produced Vg binds to Rice stripe virus (RSV) in vivo. Examination of the subunit composition of L. striatellus Vg (LsVg) revealed that LsVg was processed differently after its...

Most plant viruses are transmitted by hemipteroid insects. Some viruses can be transmitted from female parent to offspring usually through eggs, but the mechanism of this transovarial transmission remains unclear. Rice stripe virus (RSV), a Tenuivirus, transmitted mainly by the small brown planthopper (Laodelphax striatellus), is also spread to the offspring through the eggs. Here, we used the ...