Special issue: Relationship between insect vectors and plant pathogens

Abstract

Many insects including whiteflies, thrips, aphids, and planthoppers are vectors of plant pathogens such as viruses, bacteria, fungi, and nematodes. Vector-mediated transmission is one of the major propagation mechanisms of plant pathogens. Regarding the economic impact of crop production, vector insects are highly important in indirect damage by vector-borne plant pathogens as well as direct damage by themselves. The transmission mechanisms of vector-borne plant pathogens are complex including various factors such as host plants, insect vectors, plant pathogens, and endosymbiotic bacteria. However, little is known about the relationships between vector insects and plant pathogens at biochemical and molecular levels. This special issue including eight research articles will provide important information for the understanding of the role of vectors in the transmission of plant pathogens and for the development of potential application techniques for the management of vector insects as well as plant disease. Kil and Kim (arch.21992) presented a review on the small brown planthopper (Laodelphax striatellus) as a vector of the rice stripe virus, and suggested future directions for the integrated management of L. striatellus and L. striatellus-transmitted viruses. Choi and Kim (arch.21949) reported the mechanism of PGE2 mediation of egg development in Western flower thrips, Frankliniella occidentalis. These results suggest that PGE2 mediated ovarian development by affecting follicle formation and choriogenesis in F. occidentalis. Zhang et al. (arch.21970) show that Microplitis bicoloratus parasitism promotes cyclophilin D-p53 interaction to induce apoptosis of hemocytes in Spodoptera litura. These findings suggest that the CypD-p53 pathway may be an essential component of the parasitism-induced immunosuppressive response and establish a basis for further studies of parasitoid/host interactions. Khatun et al. (arch.21980) studied population dynamics and biorational management of sucking insect vectors on chili (Capsicum annuum L.) in Bangladesh. This study will aid in developing predictive models of different control agents against sucking insect vectors in vegetable crops. Lestari et al. (arch.21981) reported the genetic diversity of cryptic species of Bemisia tabaci in Asia. The Bemisia tabaci is a species complex consisting of various cryptic species worldwide. We identified the presence of 31 cryptic species from 16 countries in Asia. This study provides updated information to understand the genetic variation and geographic diversity of B. tabaci in Asia. Kim and Kim (arch.21982) studied the in vivo transient expression of a viral silencing suppressor, NSs, derived from tomato spotted wilt virus. They found that it decreases insect RNAi efficiencies. This study suggests that NSs act as a silencing suppressor in insects and would be used for a synergist for RNA pathogens to control insect pests. Lestari et al. (arch.21984) reported the identification of begomoviruses associated with the insect vector Bemisia tabaci and various host plants on Java Island, Indonesia. This study suggests B. tabaci acquires begomoviruses at different rates from plants and provides important information on the potential variation in the begomovirus transmission mechanism. Lee and Lee (arch.21987) reported that Burkholderia gut symbiont induces insect host fecundity by modulating Kr-h1 gene expression. These results suggest that Burkholderia gut symbiont modulates Kr-h1 expression to enhance ovarian development and egg production of Riptortus pedestris by increasing the biosynthesis of the two proteins. Khatun et al. (arch.21980) studied population dynamics and biorational management of sucking insect vectors on chili (Capsicum annuum L.) in Bangladesh. This study will aid in developing predictive models of different control agents against sucking insect vectors in vegetable crops. Lestari et al. (arch.21981) reported the genetic diversity of cryptic species of Bemisia tabaci in Asia. The Bemisia tabaci is a species complex consisting of various cryptic species worldwide. We identified the presence of 31 cryptic species from 16 countries in Asia. This study provides updated information to understand the genetic variation and geographic diversity of B. tabaci in Asia. This study provides updated information to understand the genetic variation and geographic diversity of B. tabaci in Asia. Lestari et al. (arch.21984) reported the identification of begomoviruses associated with the insect vector B. tabaci and various host plants on Java Island, Indonesia. This study suggests B. tabaci acquires begomoviruses at different rates from plants and provides important information on the potential variation in the begomovirus transmission mechanism. Choi and Kim (arch.21949) reported the mechanism of PGE2 mediation of egg development in Western flower thrips, Frankliniella occidentalis. These results suggest that PGE2-mediated ovarian development by affecting follicle formation and choriogenesis in F. occidentalis. Kim and Kim (arch.21982) studied the in vivo transient expression of a viral silencing suppressor, NSs, derived from tomato spotted wilt virus decreases insect RNA interference (RNAi) efficiencies. This study suggests that NSs act as a silencing suppressor in insects and would be used for a synergist for RNA pathogens to control insect pests. Kil and Kim (arch.21922) presented a review on the small brown planthopper (Laodelphax striatellus) as a vector of the rice stripe virus and suggested future directions for the integrated management of L. striatellus and L. striatellus-transmitted viruses. Zhang et al. (arch.21970) presented Microplitis bicoloratus parasitism promotes cyclophilin D-p53 interaction to induce apoptosis of hemocytes in Spodoptera litura. These findings suggest that the CypD-p53 pathway may be an essential component of the parasitism-induced immunosuppressive response and establish a basis for further studies of parasitoid/host interactions. Lee and Lee (arch.21987) reported Burkholderia gut symbiont induces insect host fecundity by modulating Kr-h1 gene expression. These results suggest that Burkholderia gut symbiont modulates Kr-h1 expression to enhance ovarian development and egg production of Riptortus pedestris by increasing the biosynthesis of the two proteins. Finally, I would like to thank Editor-in-Chief Yonggyun Kim for giving me the opportunity of being Guest Editor for this special issue on vector insects. I wish to thank all the supporters including authors and reviewers. In addition, I thank editorial staff members of Wiley who have worked diligently to get the papers published on time.