Evaluation of indigenous the nucleopolyhedrovirus (NPV) of Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) in combination with chlorantraniliprole against Spodoptera species

Background The armyworms, Spodoptera exigua (Hübner), and S. litura (Fabricius) (Lepidoptera: Noctuidae) are polyphagous pests of many cash crops. Heavy crop losses have been reported for the fruit and vegetable crops each year owing to the diverse impact on global economies. The present study was aimed to sort out a novel method of pest control using the insect’s own nucleopolyhedrosis virus (NPV) alone and in combination with a new chemistry insecticide chlorantraniliprole. Results In the study, the effect of indigenous isolated nucleopolyhedrovirus (NPV) and the chemical insecticide (chlorantraniliprole) formulations against the 2nd and 4th larval instars of S. litura and S. exigua, collected from the different geographical region of Punjab (Pakistan) province, was evaluated. Three concentrations of the NPV isolate, sub-lethal (1 × 104, 6 × 104 POB ml−1), lethal (3 × 105 POB ml−1), and chlorantraniliprole 0.01 μl l−1, were applied alone and in combination against the 2nd and 4th larval instars of both pest species. The lethal concentration of NPV + chlorantraniliprole exhibited synergistic interaction and caused high larval mortality against both instars, while in all other combinations, additive effect was observed. Moreover, NPV + chlorantraniliprole at lethal concentration exhibited decreased pupation, adult emergence, and egg eclosion. Conclusion The implications of using NPV alone and in combination with an insecticide are discussed briefly in this study.

In vivo nanoscale analysis of the dynamic synergistic interaction of Bacillus thuringiensis Cry11Aa and Cyt1Aa toxins in Aedes aegypti

The insecticidal Cry11Aa and Cyt1Aa proteins are produced by Bacillus thuringiensis as crystal inclusions. They work synergistically inducing high toxicity against mosquito larvae. It was proposed that these crystal inclusions are rapidly solubilized and activated in the gut lumen, followed by pore formation in midgut cells killing the larvae. In addition, Cyt1Aa functions as a Cry11Aa binding receptor, inducing Cry11Aa oligomerization and membrane insertion. Here, we used fluorescent labeled crystals, protoxins or activated toxins for in vivo localization at nano-scale resolution. We show that after larvae were fed solubilized proteins, these proteins were not accumulated inside the gut and larvae were not killed. In contrast, if larvae were fed soluble non-toxic mutant proteins, these proteins were found inside the gut bound to gut-microvilli. Only feeding with crystal inclusions resulted in high larval mortality, suggesting that they have a role for an optimal intoxication process. At the macroscopic level, Cry11Aa completely degraded the gastric caeca structure and, in the presence of Cyt1Aa, this effect was observed at lower toxin-concentrations and at shorter periods. The labeled Cry11Aa crystal protein, after midgut processing, binds to the gastric caeca and posterior midgut regions, and also to anterior and medium regions where it is internalized in ordered “net like” structures, leading finally to cell break down. During synergism both Cry11Aa and Cyt1Aa toxins showed a dynamic layered array at the surface of apical microvilli, where Cry11Aa is localized in the lower layer closer to the cell cytoplasm, and Cyt1Aa is layered over Cry11Aa. This array depends on the pore formation activity of Cry11Aa, since the non-toxic mutant Cry11Aa-E97A, which is unable to oligomerize, inverted this array. Internalization of Cry11Aa was also observed during synergism. These data indicate that the mechanism of action of Cry11Aa is more complex than previously anticipated, and may involve additional steps besides pore-formation activity.

Metarhizium Anisopliae Challenges Immunity and Demography of Plutella xylostella

Entomopathogenic fungi are naturally existing microbes, that can serve as a key regulator of insect pests in integrated pest management strategies. Besides having no hazardous effects on the environment, these entomopathogens are alternatives to synthetic insecticides that can control notorious insect-like Plutella xylostella, a destructive pest of cruciferous crops. Three different species of entomopathogenic fungi were evaluated before the selection (high larval mortality and least LC50) of Metarhizum anisopliae. The study was designed to investigate the mortality, development, and immune responses of P. xylostella when challenged with M. anisopliae, a naturally existing soil-borne entomopathogenic fungus. M. anisopliae resulted in high pest mortality by killing 93% of larvae. However, no statistically significant effect on hemocyte concentration was observed. The activity of enzymes (Phenoloxidase and Superoxide dismutase) and immune genes (Defensin, Spaetzle, Cecropin, Lysozyme, and Hemolin) did vary at different time points (24, 48, 72 and 96 h) after exposure to M. anisopliae. Disturbance in the biological cycles of P. xylostella was also detected, significantly shorter adult life span (8.11:6.87, M:F) and reduced fecundity (101 eggs/female) were observed along with disturbed larval and pupal duration. Results suggest that M. anisopliae can efficiently hinder the P. xylostella defense and developmental system, resulting in mortality and disturbed demography.

Complete Genome Sequence of Vibrio coralliilyticus RE22, a Marine Bacterium Pathogenic toward Larval Shellfish

Vibrio coralliilyticus RE22 is an indigenous marine pathogen that infects larval bivalve shellfish. This strain is particularly problematic in oyster hatcheries, where it causes high larval mortality.

UJI TOKSISITAS EKSTRAK ETANOL KAYU CEREMAI (Phyllanthus acidus L) TERHADAP LARVA UDANG Artemia salina DENGAN METODE BRINE SHRIMP LETHALITY TEST (BST)

<p align="center">The use of Otaheite gooseberry wood as a traditional medicine needs to be supported by scientific information about the efficacy and side effect. The objective of this research is to prove the presence of toxicity potency in ethanol extract of otaheite gooseberry wood using BST methods. An experimental research. Total sampel were 160 Brine shrimp (Artemia salina Leach) larvae. Ten larvae used in each 6 groups with 3 times replication. Each group was consecutively given 500 μg/ml, 300 μg/ml, 200 μg/ml, 100 μg/ml, 50 μg/ml, 0 μg/ml concentrate of ethanol extract of otaheite gooseberry wood, the sixth group was used as control. Data obtained by calculating amount of died larva in 24 hours after treatment. LC50 value was analyzed by probit analysis using SPSS 16.0 for windows,. Presumable compound contained in extract etanol Otaheite gooseberry wood in which have tokcixity testcase by “skrining fitokimia”. The average mortality of larvae at a concentration of 500, 300, 200, 100, 50, and 0 μg/ml consecutively were 9,33; 7,33; 4,67; 3,33; 2 and 0. The higher the extract concentration led to a growing number of high larval mortality. LC50 value of fruit extract of otaheite gooseberry wood was 275,035μg/ml. LC50 &lt;1000 μg/ml indicates ethanol extract of otaheite gooseberry wood own a potential toxicity to larvae of Artemia salina Leach.</p><p> </p>

Multiple effects of tebufenozide on the survival and performance of the spruce budworm (Lepidoptera: Tortricidae)

Aerial application of Mimic® 2LV to rising outbreak populations of the spruce budworm (Choristoneura fumiferana (Clemens); Lepidoptera: Tortricidae) in Québec, Canada, resulted in high levels of population reduction at spray deposits of 0.5–1.2 μg tebufenozide/g of foliage. Application to potted host trees in outdoor enclosures followed by bioassays revealed multiple effects on spruce budworm survival and recruitment. Chronic (14-day) exposure of late-instars to treated foliage reduced larval survival and also pupal survival, mating success, and fecundity, depending on the product concentration applied. Treatments that produced foliar deposits of ~ 0.5–1.5 μg tebufenozide/g caused high larval mortality. Exposure to deposits of ~ 0.15–0.5 μg/g caused delayed mortality during the pupal stage and reduced the mating success of survivors, while exposure to ~ 0.07–0.15 μg/g reduced the fecundity of mated females. Sublethal exposure did not affect the progeny of survivors, either in egg hatch, survival during diapause, or survival and performance after diapause. Reduced survival during late-larval and pupal stages combined with lower recruitment as a result of reduced mating success and fecundity are likely to play a role in the suppression of Mimic®-treated spruce budworm populations in the years following treatment.

Efficacy of Two Entomopathogenic Nematode Species as Potential Biocontrol Agents against the Diamondback Moth, Plutella xylostella (L.)

The diamondback moth, <em>Plutella xylostella</em> (L.) (Lepidoptera: Plutellidae) is an important pest of cruciferous crops in Iran. The susceptibility of <em>P. xylostella</em> larvae to two species of entomopathogenic nematodes (EPNs) (<em>Steinernema carpocapsae</em> and <em>Heterorhabditis bacteriophora</em>) was examined under laboratory conditions. Leaf bioassays were conducted to evaluate the nematode's capability to reach the larvae and kill them. High larval mortality (72.6-96%) was observed in laboratory experiments. The ET₅₀ of <em>H. bacteriophora</em> was higher than that of <em>S. carpocapsae</em>. The ET₅₀ of entomopatpgenic nematodes, <em>H. bacteriophora</em> and <em>S. carpocapsae</em> tested ranged from 21 to 139.7 and 11.3 to 71.4 hours, respectively. The effect of both factors infective juveniles (IJs) and exposure time of 50% (ET50) on the larval mortality was significant (df = 6; P &lt; 0.001) and (df = 2; P &lt; 0.001), respectively. This study revealed that entomopatogenic nematodes (EPNs) have great potential that should be exploited in diamondback moth, <em>P. xylostella</em> management.

Characterization, distribution, biology and impact on Italian walnut orchards of the invasive North-American leafminer Coptodisca lucifluella (Lepidoptera: Heliozelidae)

The leafminer Coptodisca sp. (Lepidoptera: Heliozelidae), recently recorded for the first time in Europe on Italian black and common walnut trees, is shown to be the North-American Coptodisca lucifluella (Clemens) based on morphological (forewing pattern) and molecular (cytochrome oxidase c subunit I sequence) evidence. The phylogenetic relatedness of three species feeding on Juglandaceae suggests that C. lucifluella has likely shifted, within the same host plant family, from its original North-American hosts Carya spp. to Juglans spp. Over the few years since its detection, it has established in many regions in Italy and has become a widespread and dominant invasive species. The leafminer completes three to four generations per year, with the first adults emerging in April–May and mature larvae of the last generation starting hibernation in September–October. Although a high larval mortality was recorded in field observations (up to 74%), the impact of the pest was substantial with all leaves infested at the end of the last generation in all 3 years tested. The distribution of the leafminer in the canopy was homogeneous. The species is redescribed and illustrated, a lectotype is designated and a new synonymy is established.

Influence of cold storage on survival and fitness of Mastrus ridens an ectoparasitoid of codling moth

The effects of cold storage on eclosion longevity and fecundity of adults of Mastrus ridens an ectoparasitoid of codling moth were investigated by holding different lifestages (4 6 8 10 and 12 weeks) Cold storage of eggs for 4 weeks resulted in high larval mortality The development periods after cold storage decreased and the immature mortality increased with advancing developmental stages before cold storage The longevity of females decreased with increasing cold storage of prepupae and pupae Neither fecundity nor oviposition period of females emerging from the seven selected treatments was different from the control (females reared at optimum temperature) Results indicated that 7 to 10dayold their survival or quality of adulthood Application of this finding will help with supply of the large numbers of parasitoids needed during the release programme

Toxicity of some bioactive medicinal plant extracts to Asian army worm, Spodoptera litura

Comparative toxicity of Andrographis paniculata (leaves), Anethum graveolens (leaves), Azadirachta indica (fruits), Cassia fistula (seeds), Cuscuta reflexa (stem), Dendropthoe falcata (leaves), Lantana camara (leaves and fruits), Melia azedarach (leaves) and Vitex negundo ( stem) plant extracts against 2nd days (first instar) and 6th days(third instar) old larvae of Spodoptera litura was studied at 5 and 10mg/ml concentration. D. falcata leaves (98.58%) and A. indica fruits= C. reflexa (85.72%) were most effective in reducing weight gain in 2nd days old larvae at 5mg/ml and at 10mg/ml, C. reflexa (98.58) followed by C. fistula seeds and L.camara fruits(both 92.86%) were effective in retarding growth. L.camara fruit extract (99.43 and 99.93%) showed greater toxicity and reduced growth as compared to A. graveolens leaves (76.16% ) at 5mg/ml. At 10mg/ml L.camara (99.94%) and A. paniculata (89.54%) leaves exhibited reduction in weight gain over control against 6d old larvae. All the medicinal plants showed varying degree of toxicity. D.falcata, A.indica and L.camara exhibited high larval mortality as compared to the other plant extracts.