The tri-trophic interaction of plants, insect herbivores, and entomoviruses is an important topic in ecology and pest control. The susceptibility of insect herbivores to entomoviruses (e.g.
View Article and Find Full Text PDFNatural acaricides are potential biorational mite control alternatives to conventional chemical acaricides. However, little is known about the molecular mechanism of defense response to natural acaricides in mites. We previously reported significant acaricidal properties of ethyl oleate (EO) against Tetranychus cinnabarinus (here referred to as a sibling species of two-spotted spider mite, Tetranychus urticae), a highly polyphagous pest devastating crops in fields and greenhouses worldwide.
View Article and Find Full Text PDFMicroplitis pallidipes Szépligeti (Hymenoptera: Braconidae) is an important parasitic wasp of second and third-instar noctuid larvae such as the insect pests Spodoptera exigua, Spodoptera litura, and Spodoptera frugiperda. As in other insects, M. pallidipes has a chemosensory recognition system that is critical to foraging, mating, oviposition, and other behaviors.
View Article and Find Full Text PDFUrbanization is a pressing challenge for earth's humans because it is changing not only natural environments but also agricultural lands. Yet, the consequences of cropland loss on pest insect populations that largely depend on these habitats remain largely unclear. We used a 17-year data set to investigate the dynamics of three moth pest species (i.
View Article and Find Full Text PDFBackground: Tri-trophic interactions among plants, insect herbivores and entomopathogens are one of the hot topics in ecology. Although plants have been shown to impact the interactions between herbivores and entomopathogens, it is still unclear how plants affect the cellular immunity of herbivores to entomopathogens.
Results: The number of hemocytes and the proportion of two main cell types (granular hemocytes and plasmatocytes), plasmatocyte-spreading rate, apoptosis rate, two Spodoptera exigua caspase (SeCasp-1, SeCasp-5) activities and gene expressions were all higher and the activities and gene expression of S.
Numerous studies have demonstrated that plant species diversity enhances ecosystem functioning in terrestrial ecosystems, including diversity effects on insects (herbivores, predators and parasitoids) and plants. However, the effects of increased plant diversity across trophic levels in different ecosystems and biomes have not yet been explored on a global scale. Through a global meta-analysis of 2,914 observations from 351 studies, we found that increased plant species richness reduced herbivore abundance and damage but increased predator and parasitoid abundance, predation, parasitism and overall plant performance.
View Article and Find Full Text PDFBackground: Interactions between herbivorous insects and entomoviruses may depend on host plant, perhaps mediated through changes in herbivore innate immunity.
Results: Caterpillars (Spodoptera exigua) fed Glycine max had high viral loads and low melanization rates together with low melanization enzyme [PO, DDC, TH] activities and gene expressions. Caterpillars fed Ipomoea aquatica had low viral loads and high melanization, gene activities and gene expressions while those fed Brassica oleracea or artificial diet had intermediate levels of each.
We determined the effects of parasitism by the endoparasitoid Microplitis pallidipes Szepligeti and/or nucleopolyhedrovirus (NPV) infection on hemocyte apoptosis of Spodoptera exigua (Hübner) larvae. Compared to healthy (control) larvae, larvae that were parasitized, virus-infected, or both all showed a significant increase in hemocyte apoptosis during 48-h observation period. The peaks of hemocyte apoptosis in parasitized, virus-infected and parasitized+infected larvae were at 12, 24 and 48 h after treatment, and were 86.
View Article and Find Full Text PDFThe extensive use of chemical pesticides for pest management in agricultural systems can entail risks to the complex ecosystems consisting of economic, ecological and social subsystems. To analyze the negative and positive effects of external or internal disturbances on complex ecosystems, we proposed an ecological two-sidedness approach which has been applied to the design of pest-controlling strategies for pesticide pollution management. However, catastrophe theory has not been initially applied to this approach.
View Article and Find Full Text PDFMany studies have supported the enemies hypothesis, which suggests that natural enemies are more efficient at controlling arthropod pests in polyculture than in monoculture agro-ecosystems. However, we do not yet have evidence as to whether this hypothesis holds true in peach orchards over several geographic locations. In the two different geographic areas in eastern China (Xinchang a town in the Shanghai municipality, and Hudai, a town in Jiangsu Province) during a continuous three-year (2010-2012) investigation, we sampled arthropod pests and predators in Trifolium repens L.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
September 2011