Population Development, Fecundity, and Flight of Spodoptera frugiperda (Lepidoptera: Noctuidae) Reared on Three Green Manure Crops: Implications For an Ecologically Based Pest Management Approach in China.

The fall armyworm, Spodoptera frugiperda (Smith), is an invasive pest of cereal crops that now inhabits southern China year-round. Cultivation of crops unsuitable as host plants has been an effective pest management strategy for some insect pests, but the effects of green manure crops on S. frugiperda have not been investigated.

Changes in both trans- and cis-regulatory elements mediate insecticide resistance in a lepidopteron pest, Spodoptera exigua.

The evolution of insect resistance to insecticides is frequently associated with overexpression of one or more cytochrome P450 enzyme genes. Although overexpression of CYP450 genes is a well-known mechanism of insecticide resistance, the underlying regulatory mechanisms are poorly understood. Here we uncovered the mechanisms of overexpression of the P450 gene, CYP321A8 in a major pest insect, Spodoptera exigua that is resistant to multiple insecticides.

Xenobiotic transcription factors CncC and maf regulate expression of CYP321A16 and CYP332A1 that mediate chlorpyrifos resistance in Spodoptera exigua.

Insect cytochrome P450 s (P450 s) are associated with the metabolic detoxification of toxic xenobiotics and their constitutive upregulation is often associated with resistance to natural and synthetic toxicants. The P450 s CYP321A16 and CYP332A1 are constitutively overexpressed in an insecticide-resistant strain of beet armyworm, Spodoptera exigua. However, the function and upstream regulation of these two P450 s remain unknown.

Molecular identification, expression and function analysis of peroxidasin in Chilo suppressalis.

Peroxidasin plays a unique role in the formation and stability of extracellular matrix (ECM) in the animal kingdom; however, it was only characterized in Diptera, not in other insect orders. In this study peroxidasin (CsPxd) was first identified and characterized from Chilo suppressalis, a lepidopteran pest. CsPxd complementary DNA with a 4080 bp open reading frame encodes a peptide of 1359 amino acids; the derived amino acid sequence of CsPxd harbors the typical structural characteristics of peroxidasin family in heme-peroxidase superfamily, including the signal peptide at N-terminal, leucine-rich repeat domain, Ig-loop motifs and peroxidase domain, signifying the extracellular location of protein and the involvement in ECM formation.

Resistance Risk Evaluated by Metaflumizone Selection and the Effects on Toxicities Over Other Insecticides in Spodoptera exigua (Lepidoptera: Noctuidae).

Metaflumizone is a novel semicarbazone insecticide. It functions as a sodium channel blocker insecticide (SCBI) with excellent insecticidal activity on most economically important lepidopterous pests. This study assessed the resistance risk of Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) to metaflumizone in the laboratory and the effects of metaflumizone selection on toxicities to other insecticides.

Insecticides induce the co-expression of glutathione S-transferases through ROS/CncC pathway in Spodoptera exigua.

Glutathione S-transferases (GSTs) are a family of multifunctional enzymes that are involved in detoxification of electrophilic toxic compounds. Although the co-induced expression of GST genes by insecticides in insects has been documented in recent years, the underlying regulatory mechanisms are not understood. In this study, a total of thirty-one cytosolic S.

Transcription factors CncC/Maf and AhR/ARNT coordinately regulate the expression of multiple GSTs conferring resistance to chlorpyrifos and cypermethrin in Spodoptera exigua.

Background: Glutathione S-transferases (GSTs) are a superfamily of multifunctional dimeric proteins existing in both prokaryotic and eukaryotic organisms. They are involved in the detoxification of both endogenous and exogenous electrophiles, including insecticides. However, the molecular mechanisms underlying the regulation of GST genes in insects are poorly understood.

Block of Kir channels by flonicamid disrupts salivary and renal excretion of insect pests.

Flonicamid is a selective insecticide for the control of sap-sucking insects; it exerts toxic effects by inhibiting insect feeding. However, its molecular target remains elusive. In this study, we functionally characterized NlKir1 channels of the brown planthopper (Nilaparvata lugens) in HEK293 cells.

Susceptibility of Sogatella furcifera and Laodelphax striatellus (Hemiptera: Delphacidae) to Six Insecticides in China.

The whitebacked planthopper, Sogatella furcifera (Horváth), and small brown planthopper, Laodelphax striatellus (Fallén), both are important crop pests throughout China, especially in rice. Application of chemical insecticides is the major control practice. Consequently, insecticide resistance has become an urgent issue.

Biochemical mechanisms for metaflumizone resistance in beet armyworm, Spodoptera exigua.

The metaflumizone, which belongs to the class of voltage-dependent sodium channel blockers, was registered to control Spodoptera exigua on vegetables in China in 2009. The present study revealed S. exigua has developed high resistance to this novel chemistry insecticide shortly after 2-3 years application in Guangdong Province of China.

Susceptibility of the rice stem borer, Chilo suppressalis (Lepidoptera: Crambidae), to flubendiamide in China.

The rice stem borer, Chilo suppressalis (Walker), is an important rice pest in China, and has evolved resistance to several classes of insecticides. Flubendiamide is a phthalic diamide insecticide that shows selective insecticidal activity against lepidopterous insects. The susceptibility of 40 field populations of C.

Antifungal agents against Aspergillus niger for rearing rice leaffolder larvae (Lepidoptera: Pyralidae) on artificial diet.

Mold contamination is an important issue in insect mass rearing. Frequently used antifungal agents such as sorbic acid and methylparaben have negative impact on many lepidopteran larvae, which might be one of the reasons for the difficulty in rearing rice leaffolder, Cnaphalocrocis medinalis (Güenée). In this study, 19 antifungal agents, including 7 food preservatives, 6 antifungal drugs, and 6 agricultural fungicides, were screened for their inhibitory activities on Aspergillus niger in diets.

Resistance in Cnaphalocrocis medinalis (Lepidoptera: Pyralidae) to new chemistry insecticides.

The control of rice leaffolder, Cnaphalocrocis medinalis (Guenée), depended mainly on the insecticide application in China for a long time, and the resistance development impacted the effects of insecticide application. In this study, 13 conventional and new chemistry insecticides were assayed for the toxicities to the larvae of rice leaffolder collected from Nanning, Changsha, and Nanjing, China, with rice seedling dip method during 2011-2013. Among the tested chemicals, macrolide insecticides spinetoram, spinosad, abamectin, and emanectin benzoate have the highest toxicities, whereas monosultap and Bt have the least toxicities to this insect.

Changes in insecticide resistance of the rice striped stem borer (Lepidoptera: Crambidae).

Application of insecticides is the most important method to control Chilo suppressalis (Walker) (Lepidoptera: Crambidae), and continuous use of individual insecticides has driven the rapid development of insecticide resistance in C. suppressalis during the past 30 yr. Monitoring insecticide resistance provides information essential for integrated pest management.

Susceptibility baseline and chlorantraniliprole resistance monitoring in Chilo suppressalis (Lepidoptera: Pyralidae).

Chlorantraniliprole, a new anthranilic diamide insecticide, has been commercialized in China since 2008 for controlling of several lepidopterans, including rice stem borer, Chilo suppressalis Walker. Chemical control of this pest has become difficult because of its resistance development to many conventional insecticides. To facilitate chlorantraniliprole-resistance monitoring, seedling dip bioassays were conducted in 2011 and 2012 to assess the susceptibility of 30 populations of C.

Geographic susceptibility of Chilo suppressalis Walker (Lepidoptera: Crambidae), to chlorantraniliprole in China.

Background: Chilo suppressalis Walker, the rice striped stem borer (RSSB) is one of the most serious lepidopteron insect pests of rice in Asia. The registration of chlorantraniliprole added an option for the chemical control of RSSBs.

Results: In this study, the geographic variability of susceptibility of field-collected RSSBs to chlorantraniliprole was assessed to establish a baseline for future comparisons of field population responses to the increased use of chlorantraniliprole products.

Regression analysis of dynamics of insecticide resistance in field populations of Chilo suppressalis (Lepidoptera: Crambidae) during 2002-2011 in China.

To understand the evolution of insecticide resistance in the Asiatic rice borer, Chilo suppressalis (Walker) (Lepidoptera: Crambidae), in field, regression analysis based on a linear or nonlinear model was adopted for analyzing resistance dynamics to six insecticides of two field populations of the Lianyungang (LYG) and Ruian (RA) populations during 2002-2011. For the low-level resistance population, LYG population, sustained susceptibilities to abamectin and fipronil were seen for 10 yr; a polynomial curve regression model showed an increase in resistance to chlorpyrifos; exponential growth models fit to the resistance dynamics to triazophos and deltamethrin, and a sigmoidal growth curve for monosultap. For the high-level multiple resistance population, RA population, a slight increase from susceptible to a minor resistance to abamectin could be modeled by a polynomial cubic equation; an exponential growth model fit to the increase of resistance to fipronil from 8.

Differential resistance and cross-resistance to three phenylpyrazole insecticides in the planthopper Nilaparvata lugens (Hemiptera: Delphacidae).

Cross-resistance to two fipronil analogs, butene-fipronil and ethiprole, was detected in fipronil-resistant field populations and a resistant laboratory strain of the planthopper Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), although the two analogs have not been used widely in rice-growing areas in China. The results showed that six field populations with 23.8-43.

Assessment of resistance risk in Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) to chlorantraniliprole.

Background: Beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), is a major pest of numerous cultivated crops. Chlorantraniliprole, the first commercialised ryanodine receptor insecticide from the anthranilic diamide class, has exceptional insecticidal activity on a range of lepidopteran pests. The aim of this study was to assess the resistance of S.

Insecticide susceptibility of Cnaphalocrocis medinalis (Lepidoptera: Pyralidae) in China.

Insecticide control is the major measure for suppression of Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae) damage, and a few insecticides used for long time have proved to fail to control this pest in China. Several new chemicals have been introduced for control of C. medinalis.

Molecular characterization and developmental expression of the gene encoding the prothoracicotropic hormone in the beet armyworm, Spodoptera exigua.

Prothoracicotropic hormone (PTTH), a neuropeptide hormone stimulating the prothoracic glands to synthesize ecdysone, plays an important role in regulating postembryonic development in insects. The cDNA encoding PTTH was isolated and sequenced from the beet armyworm, Spodoptera exigua (Spe). The deduced amino acid sequence is composed of a signal peptide, a peptide (65 amino acids) of unknown function, and a mature PTTH molecule (111 amino acids).