The brown planthopper (BPH) Nilaparvata lugens, whitebacked planthopper (WBPH) Sogatella furcifera and smaller BPH Laodelphax striatellus increasingly exhibit resistance to insecticides and adaptation to resistant varieties, so they threaten food security. This review draws together, for the first time, information on the parasitoids of planthopper pests of rice from the non-English literature published in Asia. This is integrated with the English language literature to provide a comprehensive analysis. Planthopper pests of rice are attacked by a large range of parasitoids from Strepsiptera, Diptera and, especially, Hymenoptera. Levels of field parasitism vary widely between parasitoid species and locations. For many taxa, especially within Mymaridae, there is evidence that non-crop habitats are important as overwintering habitat in which alternative hosts are available. These source habitats may promote early season parasitism of pest Hemiptera in rice crops, and their movement into crops could be manipulated with applications of herbivoreinduced plant volatiles. Non-crop plants can also provide nectar to improve parasitoid longevity and fecundity. Despite evidence for the importance of environmental factors affecting parasitoids of rice pests, the use of habitat manipulation to enhance biological control in the world's most important crop is surprisingly underrepresented in the literature. Current research in China, Vietnam and Thailand on ecological engineering, carefully selected vegetation diversity introduced without disrupting profitable farming, is briefly reported. Although the most important pest, BPH (N. lugens), is a migratory species, maintaining local communities of parasitoids and other natural enemies offers scope to prevent even r-selected pests from reaching damaging population densities.

Conditionally replicating adenoviruses (CRAds) represent a promising new platform for anticancer therapy. However, CRAds have been evaluated little in hematopoietic malignancies because of the lack of expression of coxsackie adenovirus receptor (CAR) on their cell surface. In this study, we showed that CAR was expressed on two types of lymphoblastic leukemia cell lines and primary leukemia cells, and that ZD55, a CRAd, exerted a potent antileukemia effect in vitro and in vivo. Furthermore, ZD55 expressing melanoma differentiation-associated gene-7/interleukin-24 (ZD55-IL-24) elicited significant enhanced antileukemia activity comparing with ZD55, concomitant with upregulation of RNA-dependent protein kinase R (PKR), increased phosphorylation of p38 mitogen-activated protein kinase (MAPK), and induction of endoplasmic reticulum (ER) stress. These data for the first time indicate that MDA-7/IL-24 exerts its antitumor effect on leukemia cells via multiple pathways, and suggest that oncolytic adenoviruses, ZD55 and ZD55-IL-24 could potentially be used against CAR-expressing hematological malignancies such as B-lymphoblastic leukemia/ lymphoma and some myeloid leukemia.

Silicon (Si) is important in plant defenses that operate in a direct manner against herbivores, and work in rice (Oryza sativa) has established that this is mediated by the jasmonate signaling pathway. Plant defenses also operate indirectly, by the production of herbivore induced plant volatiles (HIPVs) that attract predators and parasitoids of herbivores. These indirect defenses too are mediated by the jasmonate pathway but no earlier work has demonstrated an effect of Si on HIPVs. In this study, we tested the effect of Si supplementation versus Si deprivation to rice plants on subsequent HIPV production following feeding by the important pest, rice leaffolder (Cnaphalocrocis medinalis). Gas chromatography–mass spectrometry analyses showed lower production of α-bergamotene, β-sesquiohellandrene, hexanal 2-ethyl, and cedrol from +Si herbivore-infested plants compared with -Si infested plants. These changes in plant chemistry were ecologically significant in altering the extent to which parasitoids were attracted to infested plants. Adult females of Trathala flavo-orbitalis and Microplitis mediator both exhibited greater attraction to the HIPV blend of +Si plants infested with their respective insect hosts compared to -Si infested plants. In equivalent studies using RNAi rice plants in which jasmonate perception was silenced there was no equivalent change to the HIPV blend associated with Si treatment; indicating that the effects of Si on HIPVs are modulated by the jasmonate pathway. Further, this work demonstrates that silicon alters the HIPV blend of herbivore-infested rice plants. The significance of this finding is that there are no earlier-published studies of this phenomenon in rice or any other plant species. Si treatment to crops offers scope for enhancing induced, indirect defenses and associated biological control of pests because parasitoids are more strongly attracted by the HIPVs produced by +Si plants.

Abstract:The ecological effects of plant-virus-vector interactions on invasion of alien plant viral vectors have been rarely investigated. We examined the transmission of Tomato yellow leaf curl China virus (TYLCCNV) by the invasive Q biotype and the indigenous ZHJ2 biotype of the whitefly Bemisia tabaci, a plant viral vector, as well as the influence of TYLCCNV-infection of plants on the performance of the two whitefly biotypes. Both whitefly biotypes were able to acquire viruses from infected plants and retained them in their bodies, but were unable to transmit them to either tobacco or tomato plants. However, when the Q biotype fed on tobacco plants infected with TYLCCNV, its fecundity and longevity were increased by 7-and 1-fold, respectively, compared to those of the Q biotype fed on uninfected tobacco plants. When the ZHJ2 biotype fed on virus-infected plants, its fecundity and longevity were increased by only 2-and 0.5-fold, respectively. These data show that the Q biotype acquired higher beneficial effects from TYLCCNV-infection of tobacco plants than the ZHJ2 biotype. Thus, the Q biotype whitefly may have advantages in its invasion and displacement of the indigenous ZHJ2 biotype.

Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24) is a novel candidate of tumor suppressor that can selectively induce apoptosis experimentally in a spectrum of human cancer cells including leukemia cells. However, a recent study suggests that mda-7/IL-24 promotes the survival of chronic lymphocytic leukemia B-cells. In this study, we showed that mda-7/IL-24 was constitutively expressed in leukemia cell lines and primary acute myeloid leukemia samples. Using a conditionally replicating adenovirus expressing mda-7/IL-24 (ZD55-IL-24), we showed that enforced expression of mda-7/IL-24 in leukemia cells induced autophagy, which was triggered by the upregulation of Beclin-1. Immunofluorescence and coimmunoprecipitation studies suggested that mda-7/IL-24 protein interacts with Beclin-1. Class III PI3K/Beclin-1 complex was shown involved in the mda-7/IL-24-induced autophagy. Moreover, autophagy inhibition by phosphatidylinositol 3-kinase inhibitor, wortmannin, resulted in a reduced Beclin-1 expression and autophagosome formation associated with significantly enhanced cell death. Importantly, the combination of ZD55-IL-24 with wortmannin elicited a strongly enhanced antileukemia efficacy in established leukemia xenografts. These results suggest that mda-7/IL-24-induced autophagy in leukemia cells may provide survival advantage and mda-7/IL-24 combined with agents that disrupt autophagy is a promising new strategy for the treatment of leukemia.

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1 The rice leaffolder Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae) is a serious rice pest in Asia. The conspicuous foliar damage caused by C. medinalis larvae leads to early-season insecticide applications that disrupt the biological control of this and other pest species. 2 Despite the often dramatic impact of C. medinalis, rice plants can tolerate severe defoliation with no impact on grain yield, although persuading farmers to withhold insecticide application has proven very difficult. 3 The present review assesses the prevention of damage caused by C. medinalis via biological control using parasitoids. Information on the indigenous parasitoids of C. medinalis is drawn together for the first time from the non-English literature published in Asia. This is integrated with the wider English language literature to provide a comprehensive analysis of the parasitoid fauna. 4 Survey studies have been conducted in many Asian countries in recent decades, showing that parasitoids of rice pests can achieve high rates of parasitism but are far from consistent as a mortality factor. There is much less work available on the biology of leaffolder parasitoids in rice and there is an unexpected dearth of studies regarding increasing their performance by providing nectar sources, which is a widely explored approach for other crop systems. 5 It is concluded that the recently reported work in which nectar plants are established on rice bunds to support planthopper parasitoids may have significant benefit for leaffolder parasitoids. The use of plant species, however, that are selective in not allowing adult moths to feed will be essential.