Reduced Progeny Production Research Articles

Effect of Insecticides on Generative Potential of Entomopathogenic Nematode, Steinernema abbasi PN-1 in Spodoptera litura Fabricius

This study aimed to evaluate the effects of different insecticides at varying concentrations on the progeny production of the entomopathogenic nematode Steinernema abbasi PN-1 in Spodoptera litura larvae, with a focus on determining the insecticides' compatibility with biological control agents. S. litura larvae were treated with a mixture of S. abbasi PN-1 and insecticides (fipronil, emamectin benzoate, cyantraniliprole, indoxacarb, and chlorantraniliprole) at three different concentrations (lower, medium, and higher). Progeny production of S. abbasi PN-1 was assessed and compared across treatments, with control groups consisting of larvae treated with S. abbasi PN-1 alone. The study found that progeny production was significantly influenced by the type and concentration of insecticides. Fipronil exhibited the least negative impact on progeny production across all concentrations, followed by emamectin benzoate, cyantraniliprole, indoxacarb, and chlorantraniliprole, with the latter showing the most significant inhibitory effects. Higher concentrations of insecticides resulted in a greater reduction in progeny production, indicating a dose-dependent relationship. The results suggest that certain insecticides, particularly at higher concentrations, can negatively affect the progeny production of S. abbasi PN-1, potentially compromising the effectiveness of EPNs in integrated pest management (IPM) programs. The study highlights the importance of selecting compatible insecticides and their appropriate concentrations to enhance the success of biological control strategies involving EPNs.

Efficacy of pulegone, and eugenol alone and in combination with synthetic insecticides for the management of three stored product beetle pests

The rising public concern over the safety and environmental impact of synthetic insecticides, along with the evolution of resistance, are driving entomologists to search for new pest control alternatives. Essential oils and their constituents have been proposed as the most promising alternatives due to their wide spectrum of biological activity and synergistic interaction with traditional insecticides. Therefore, the present work evaluated the toxicity of a monoterpene, pulegone (250 and 500 mg/kg), and a phenylpropene, eugenol (250 and 500 mg/kg), alone and in combination with deltamethrin (0.1 and 0.25 mg/kg), pirimiphos-methyl (2.5 and 5.0 mg/kg), and thiamethoxam (0.1 and 0.5 mg/kg) against Rhyzopertha dominica, Sitophilus oryzae, and Tribolium castaneum on wheat grains. Pulegone exerted significant toxicity at 250 and 500 mg/kg against the three beetle species, with complete mortality after 14 days of exposure, complete inhibition of progeny production, and complete protection of treated wheat grain after 75 days of treatment. While eugenol at the higher application rate tested (500 mg/kg) caused 68.3, 31.7, and 5.0 % mortality in adults of R. dominica, S. oryzae, and T. castaneum, with reduction in progeny production of 81.3, 67.7, and 79.7%, respectively. In combination treatments, pulegone reduced toxicity against tested insect species when mixed with the three insecticides, indicating an antagonistic effect. While treated wheat grains with binary mixtures of eugenol (500 mg/kg) with deltamethrin, pirimiphos-methyl, and thiamethoxam enhanced their toxicity, resulting in higher mortality rates, fewer emerged adults, and a lower loss in weight of wheat grains than those obtained in individual treatments. Based on these findings, we suggest that pulegone and eugenol might be viable options for usage in protecting stored wheat against the tested insect species. Additionally, eugenol has the potential to enhance the toxicity of synthetic insecticides, which could reduce their application rates and manage the resistance to these insecticides.

Efficacy of diatomaceous earth, and entomopathogenic fungi, Beauveria bassiana, and Trichoderma asperellum in combination and separately, against Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae)

BackgroundCallosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) is one of the most significant pests infesting leguminous crops since it is found in tropical and subtropical climates, as well as in Turkey. The most often utilized methods of managing these insects are fumigants and synthetic insecticides. However, chemical pesticides lead to increased risks for human health, chemical residues, insect resistance, and environmental contamination. Therefore, the present study aimed to determine the effectiveness of entomopathogenic fungi [Beauveria bassiana (Bb) and Trichoderma asperellum (Ta)] individually or in combination with diatomaceous earth (DE) against C. maculatus. The fungi Bb and Ta were applied at 1 × 104, 1 × 106 and 1 × 108 spores/kg of chickpea seeds and mixed with 200, 400, 800 mg/kg of DE. Additionally, the progeny production of the insect on chickpea in the different treatments was evaluated after 40 days of exposure.ResultsIn all individual treatments, total adult mortality of the insect was accomplished solely by using the highest DE treatment rate (800 mg/kg) after 7 days. The most effective combination that was a mixture at highest application rate of DE/Bb (800 mg/kg of DE + 1 × 108 spores/kg of Bb) caused 100% mortality after 6 days of exposure and had the lowest LT50 (2.97) and LT90 (5.46) values (days). Although other DE/Bb binary combinations caused 100% mortality of C. maculatus 6 days after treatment, their LT50 and LT90 values were lower. Insect mortalities were 100% in all DE/Ta binary combinations on days 7 and 8, and the highest application rate (800 mg/kg of DE + 1 × 108 spores/kg of Ta) of this combination had the lowest LT50 (4.14) and LT90 (6.17) values (days). Individual treatments of DE, Bb, Ta and their binary combinations caused significant reduction in progeny production after 40 days of treatment compared with progeny production in the control of C. maculatus. The highest progeny production (88.9%) was observed at the highest treatment rate of DE/Bb combinations (800 mg/kg of DE + 1 × 108 spores/kg of BB).ConclusionsThe treatments used in combination of Bb or Ta with DE resulted in increased insecticidal effectiveness against C. maculatus. These natural agents caused considerable decreasing of progeny production of the pest. Even with reduced application rates, the agents with a promising potential against the pest showed acceptable results in binary combinations.

Combinations of Beauveria bassiana and spinetoram for the management of four important stored-product pests: laboratory and field trials

The current study examines the efficacy of the semi-synthetic insecticide spinetoram and entomopathogenic fungi Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae) as wheat protectants against the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), the granary weevil, Sitophilus granarius (L.) (Coleoptera: Curculionidae), and the khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae), under laboratory and field trials. One dose of B. bassiana, i.e., 1 × 107 conidia/kg wheat, two doses of spinetoram, i.e., spine1: 0.05 ppm (mg/kg wheat), spine2: 0.1 ppm, and their combinations (Bb + spine1, Bb + spine2) were evaluated at 20, 25, and 30 °C. All treatments provided significantly higher mortality at 30 °C compared with the other two temperatures. Maximum mortality levels were observed in the treatments where B. bassiana was combined with the higher dose of spinetoram (0.1 ppm). All treatments reduced progeny production in comparison with the control groups. Maximum progeny reduction was observed at 30 °C, on wheat treated with the Bb + spine2 combination. The combination Bb + spine2 also provided elevated mortality rates in both laboratory and field persistence trials, but at 180 days caused moderate mortality to all tested insect species. Concerning progeny, at laboratory persistence trials, the combination Bb + spine2 exhibited the lowest offspring emergence to all tested species compared to the other treatments and control. Overall, our study showed that R. dominica was the most susceptible species followed by S. granarius, T. castaneum, and T. granarium. Our findings revealed that the combination of B. bassiana and spinetoram may be a useful tool for efficient and advanced integrated pest management strategies for long storage periods under multiple temperatures.

Diatomaceous earth low-lethal dose effects on the fitness of entomopathogenic fungus, Beauveria bassiana, against two coleopteran stored product pests

Efficacy of different doses of the Beauveria bassiana-IRAN441C alone (66,125, 250, 500, 1000 mg conidia. Kg−1 grains) and combined with a low-lethal dose (LD25) of diatomaceous earth (DE) SilicoSec® as lethal agents were assessed against the adults of Callosobruchus maculatus (F.) (Chrysomelidae) on mung, and cowpeas, and Oryzaephilus surinamensis (L.) (Silvanidae) on wheat and barley seeds. In both species, mortality reached 60–73% in B. bassiana alone and 83–100% in fungus combined with the DE at the highest dose. A synergistic effect between B. bassiana conidia and the DE was confirmed. The DE low-lethal dose alters fungal mycosis and sporogenesis (conidia mL−1) rates in the infected cadavers. The adult populations of both species were suppressed desirably despite a decrease in the number of cadaver-derived mycosis and their spore production at the highest combination doses (1000 mg kg−1+ LD25 of DE). Seed type had no significant effect on mycosis and sporogenesis on both insects in several combination doses. The cadaver-derived aerial conidia germination rate was increased in the presence of DE low-lethal dose, but it declined by increasing the fungal dose. Type of commodity failed to affect the germination rate of O. surinamensis-derived conidia; however, the mung bean intensified this case for another insect. In both beetles, offspring's emergence was suppressed dose-dependently seven weeks after removing exposed parents to the lethal agents as well it was more in doses mixed with DE. The most significant reduction in progeny production of treated C. maculatus occurred on cowpeas and that of treated O. surinamensis on wheat seeds. Our findings demonstrate that DE's low-lethal dose enhances the virulence of B. bassiana in the various mixtures synergistically, and co-applications of the two substances were feasible. As well, the lethal agents' adverse effects were found to carry over onto both species' offspring during two-month storage time.

Human blood microRNA hsa-miR-21-5p induces vitellogenin in the mosquito Aedes aegypti

Mosquito vectors transmit various diseases through blood feeding, required for their egg development. Hence, blood feeding is a major physiological event in their life cycle, during which hundreds of genes are tightly regulated. Blood is a rich source of proteins for mosquitoes, but also contains many other molecules including microRNAs (miRNAs). Here, we found that human blood miRNAs are transported abundantly into the fat body tissue of Aedes aegypti, a key metabolic center in post-blood feeding reproductive events, where they target and regulate mosquito genes. Using an artificial diet spiked with the mimic of an abundant and stable human blood miRNA, hsa-miR-21-5p, and proteomics analysis, we found over 40 proteins showing differential expression in female Ae. aegypti mosquitoes after feeding. Of interest, we found that the miRNA positively regulates the vitellogenin gene, coding for a yolk protein produced in the mosquito fat body and then transported to the ovaries as a protein source for egg production. Inhibition of hsa-miR-21-5p followed by human blood feeding led to a statistically insignificant reduction in progeny production. The results provide another example of the involvement of small regulatory molecules in the interaction of taxonomically vastly different taxa.

Insecticidal effect of thiamethoxam against seven stored-product beetle species

Bioassays were carried out in order to assess the insecticidal value of the neonicotinoid thiamethoxam in different concentrations against seven important beetle species that are major pests of stored grains. These species were Prostephanus truncatus (Horn), Rhyzopertha dominica (F.), Sitophilus oryzae (L.), Sitophilus granarius (L.), Oryzaephilus surinamensis (L.), Tribolium confusum Jacquelin du Val, and Cryptolestes ferrugineus (Stephens). Adults of these species were exposed to grains treated with thiamethoxam at dose rates of 0 (control), 0.01, 0.1, 0.5, 1, 2, 5 or 10 ppm. Our results indicate that with the increase of the insecticide concentration, there was also an increased adult mortality and a reduction in progeny production. To illustrate the relative sensitivity to thiamethoxam of the seven insects, starting with the most susceptible, we can classify them as P. truncatus > R. dominica = S. granarius = S. oryzae > T. confusum = O. surinamensis > C. ferrugineus. The findings of the present research show that thiamethoxam can be recommended for its efficacy at a rate of 10 ppm and duration of 14 days that could be used to control all insects and their progeny.

Insectıcıdal actıvıtıes of Anethum graveolens and Illıcıum verum essentıal oıls agaınst Sıtophılus zeamaıs

Inappropriate use of synthetic insecticides in pest management programs contribute in ozone depletion, neurotoxicity, carcinogenicity, teratogenicity, mutagenesis and resistance. These negative outcomes have diverted attention towards the use of plant products in insect’s population management. In this study, dill (Anethum graveolens) and star anise (Ilicium verum) essential oils were isolated by hydrodistillation method using clevenger apparatus, and evaluated for repellent, toxic and oviposition inhibitory potential against maize weevil Sitophilus zeamais (Coleoptera: Curculionidae) by fumigation and contact methods. In toxicity assay by fumigation method, median lethal concentrations (LC50) recorded were 0.316 and 0.243 μlcm-3 air; 0.362 and 0.284 μlcm-3; and 0.497 and 0.418 μlcm-3 of A. graveolens and I. verum oils and pure limonene after 24 and 48h exposure to S. zeamais adults, respectively. In contact toxicity assay, LC50 were 0.219 and 0.159 μlcm-2 area; 0.269 and 0.226 μlcm-2; and 0.567 and 0.386 μlcm-2 of A. graveolens and I. verum oils and pure limonene after 24 and 48 h exposure to S. zeamais adults, respectively. Both A. graveolens and I. verum oils and limonene reduced progeny production and acetylcholinesterase activity in S. zeamais adults when fumigated with sub-lethal concentrations. The outcomes of this study will help in preparation of essential oil based formulations for stored grain insect pest management.

Efficacy of low-dose combinations of diatomaceous earth, spinosad and Trichoderma harzianum for the control of Callosobruchus maculatus and Callosobruchus chinensis on stored cowpea seeds

The insecticidal efficacy of diatomaceous earth (DE), spinosad (SP) and Trichoderma harzianum (TH), and their combinations was evaluated against the adults of Callosobruchus maculatus (F.) and Callosobruchus chinensis L. (Coleoptera: Chrysomelidae: Bruchinae) on cowpea seeds. The application rates used in this study were 100 and 500 mg/kg (ppm) for DE, 0.1 and 0.5 mg/kg (ppm) for SP, and 1 × 104 and 1 × 106 spores/kg for TH. The adult mortality of both insect species was counted after 7 days. Progeny reduction after 40 and 80 days, and cowpea seeds weight loss after 80 days were determined for all tested individual and combined treatments. In individual treatments, DE caused higher mortality of both insects than SP and TH. DE induced 76.4 and 78.7% mortality of C. maculatus and C. chinensis, respectively, at 500 mg/kg. The ternary combined treatments of SP, TH and DE showed higher insecticidal activity than binary combination and individual treatments. Complete adult mortality of both insect species was achieved using a ternary mixture at application rate of 500 mg/kg of DE, 0.5 mg/kg of SP and 1 × 106 spores/kg of T. harzianum. All individual and combined treatments significantly reduced progeny production of both insect species after 40 and 80 days. However, the ternary mixture treatments strongly suppressed progeny production. Similarly, ternary mixture treatments protected cowpea seeds from damage and weight loss caused by both insect species for 80 days. These results indicate that the combinations of DE, SP and TH could be successfully used for the management of C. maculatus and C. chinensis in stored cowpea seeds.

Nanoemulsions of Chamomile and Cumin Essential Oils: As an Alternative Bio-rational Control Approach against the Red Flour Beetle, Tribolium castaneum

Essential oil (EO) nanoemulsion is a new approach to formulate and convey insecticides and to minimize some of the common shortcomings associated with the conventional formulations of synthetic insecticides and also of essential oils. The aim of the present was to develop an oil-in-water (O/W) nanoemulsion of the essential oils of chamomile (Matricaria chamomilla L.) and cumin (Cuminum cyminum L.), and assess their lethal and sublethal toxicity to the red flour beetle Tribolium castaneum (Hersbt). The nanoemulsions of EO were characterized by droplet sizes of 341.4 and 387.1 nm for the chamomile and cumin, respectively. The polydispersivity (PDI), viscosity (cP), zeta potential (mV) and conductivity (mS/cm) of the nanoemulsions were also characterized. The cumin nanoemulsion exhibited higher lethal toxicity to the flour beetle, besides of compromising the insect weight gain while impairing their food consumption and conversion rate in sublethal exposure. Cumin EO nanoemulstion also sparked anti-feeding activity, reduced progeny production and prevented grain weight loss by the red flour beetle indicating its potential for stored product protection.

Toxic Effects of Hydroxyl- and Amine-functionalized Silica Nanoparticles (SiO2 and NH2-SiO2 NPs) on Caenorhabditis elegans

ABSTRACT Silica nanoparticles (SiO2 NPs) are engineered nanomaterials (ENMs) that have a wide range of application. Increased use in manufacturing has led to concerns about their environmental impact and possible adverse health effects. We conducted a comparative toxicity assessment of bare SiO2-NPs and amine-functionalized SiO2 NPs (NH2-SiO2 NPs) utilizing the Caenorhabditis elegans (C. elegans) in vivo model. L1 nematodes were exposed to exposure concentrations of 0.25, 0.5, 2.5, and 5 mg mL–1 until the worms reached the L4 stage. The chronic lethality and lifespan assays revealed a significant decrease in survival rate and lifespan at 2.5 and 5 mg mL–1 for nematodes exposed to bare SiO2 NPs (89% and 88%; 22 days, p < 0.05 and 14 days, p < 0.05) and at 5 mg mL–1 for the NH2-SiO2 NPs-exposed group (86%; 20 days, p < 0.001). Exposure to all SiO2 NP concentrations reduced progeny production to 79–60% while exposure to 2.5 and 5 mg mL–1 of NH2-SiO2 NPs significantly reduced the brood size to 64–63%. Neurobehavioral toxicity was also observed in the SiO2 NP-exposed worms, which displayed significantly decreased head thrashing for up to 92–71% and in the NH2-SiO2 NPs-exposed worms which showed significantly reduced head thrashing movement for up to 91–85% at concentrations of 0.5-5 mg mL–1. Body bending movements were also significantly reduced at 0.5–5 mg mL–1 SiO2 NPs (71–34%) and 2.5–5 mg mL–1 NH2-SiO2 NPs (94–66%). Significant shortening of body size was also observed in nematodes exposed to 0.5–5 mg mL–1 for both SiO2 NPs (93–81%) and NH2-SiO2 NPs (94–88%). Overall, bare SiO2 NPs were observed to be more toxic due to the negatively charged surface OH groups, which may have disrupted protein homeostasis, resulting in the observed toxicities. We suggest that functionality is an important indicator in nanosafety evaluations.

Contact Toxicity of Filter Cake and Triplex Powders From Ethiopia Against Adults of Sitophilus zeamais (Coleoptera: Curculionidae).

Filter cake and Triplex are powdered by-products of aluminum sulfate and soap factories in Ethiopia, respectively. This study was aimed at determining contact toxicity of filter cake and Triplex powders against maize weevil, Sitophilus zeamais Motschulsky. Lethal concentrations for 99% mortality (LC99) against S. zeamais were determined by exposing adults for 12 h to filter cake (0.5-8 g/m2) and Triplex (1-9 g/m2) in concrete arenas. Lethal times for 99% mortality (LT99) were determined by exposing adults over time (1-24 h) in concrete arenas to 3 g/m2 of filter cake and 9 g/m2 of Triplex. Exposed adults were transferred to containers with 30 g of organic wheat and held at 28°C and 65% RH for 14 d to determine mortality. LC99 values for S. zeamais adults were 7.54 and 23.46 g/m2 when exposed to filter cake and Triplex, respectively. The corresponding LT99 values were 21.92 and 39.62 h when exposed to filter cake and Triplex, respectively. Effective concentrations and times for the 99% reduction of progeny production were determined from percentage reduction in adult progeny relative to production in control treatments after 42 d. EC99 values for progeny reduction were 2.48 and 18.59 g/m2 for filter cake and Triplex treatments, respectively. The corresponding ET99 values for progeny reduction were 17.49 and 22.31 h for filter cake and Triplex, respectively. Sitophilus zeamais exposed to filter cake produced lower percentage insect-damaged kernels and weight loss than Triplex. Filter cake was more efficacious against S. zeamais than Triplex.

Toxicity of fine powders, filter cake and Triplex against Sitophilus zeamais adults:

Filter cake and Triplex are powdered by-products of aluminum sulfate and soap factories, respectively. There is limited data about the use of these powders as grain protectants. This study was aimed at determining contact toxicity of both powders against Sitophilus zeamais, a common pest of stored grains. Lethal concentration of both powders to S. zeamais was determined by exposing 10 adults for 12 h in 9 cm diameter concrete arenas inside Petri dishes dusted with filter cake (0 - 8 g/m2) or Triplex (0 - 9 g/m2). Lethal time was determined by exposing adults to 3 g/m2 filter cake and 9 g/m2 Triplex for 1 to 24 h. Each treatment was replicated 3 times. At the intended exposure time, adults were transferred to 150-ml round plastic containers with 30 g of wheat and held at 28 degree Celsius and 65% r.h. for 14 d to determine mortality. Adult progeny production was determined after 42 d. A 50% mortality of adults was obtained at 0.61 g/m2 of filter cake and 1.61 g/m2 of Triplex concentrations with a 12 h exposure. The corresponding effective concentrations for 50% reduction of progeny production were 0.18 g/m2 of filter cake and 2.66 g/m2 of Triplex. Lethal times for 50% mortality of adults after exposure to 3 g/m2 of filter cake and 9 g/m2 of Triplex were 4.42 and 4.29 h, respectively. The corresponding effective times for 50% reduction of progeny production after exposure to 3 g/m2 of filter cake and 9 g/m2 of Triplex were 1.74 and 2.34 h respectively. The overall result indicated that filter cake was highly toxic to S. zeamais than Triplex. Therefore, filter cake is a potential powder to be included in the integrated pest management practice in small holder farmers’ storage structures after tested under real field conditions.

Effects of Hemizygia welwitschii leaf extract fractions on postharvest infestation of maize by Sitophilus zeamais Motsculsky (Coleoptera: Curculionidae): Presentation

As part of on-going efforts to use eco-friendly alternatives to chemical pesticides, leaf powder of Hemizygia welwitschii was sequentially extracted in hexane, acetone and methanol. Bioassays were carried out to establish the most active fraction(s) against Sitophilus zeamais in maize. Maize grains (50 g) were treated with concentrations within the range 2, 4, 6, and 10 g/kg of extract and Azadirachta indica seed oil (positive control) in the laboratory. The total number of progeny emerging from grains infested separately with S. zeamais eggs, larvae and pupae were recorded. Adult mortality counts were carried out 1, 3, 7 and 14 d post-exposure. Acetone extract was more toxic to the eggs, larvae and pupae than the other extracts, inhibiting progeny production by 90.90%, 88.10% and 100%, respectively, at the concentration 10 g/kg. For the same concentration, A. indica seed oil reduced progeny production by 100% for eggs, 96.08% for larvae and 70.93% for pupae. Hexane extract was more potent to the adult weevil than the other extracts, recording 100% mortality for the concentration 10 g/kg within 14 d. LC50 values were 0.78 (Hexane), 5.52 (acetone) and 1.69 g/kg (methanol). Extracts of H. welwitschii leaves had sufficient efficacy to be a component of storage pest management package for S. zeamais.

Effects of Spinosad, Imidacloprid, and Lambda-cyhalothrin on Survival, Parasitism, and Reproduction of the Aphid Parasitoid Aphidius colemani.

Insecticides can affect biological control by parasitoids. Here, we examined the lethal and sublethal effects of two conventional insecticides, imidacloprid and lambda-cyhalothrin, and a reduced-risk bioinsecticide, spinosad, on the aphid parasitoid Aphidius colemani Viereck (Hymenoptera: Braconidae). Concentration-mortality curves generated from insecticide residue bioassays found that wasps were nearly 20-fold more susceptible to spinosad than imidacloprid and lambda-cyhalothrin. Imidacloprid and lambda-cyhalothrin compromised adult parasitoid longevity, but not as dramatically as spinosad: concentrations >200 ng spinosad/cm2 reduced wasp longevity by half. Imidacloprid and lambda-cyhalothrin also compromised aphid parasitism by wasps. Although increasing imidacloprid concentrations led to increased host viability and reduced progeny production, lambda-cyhalothrin did not affect viability of parasitized hosts or parasitoid progeny production in a dose-dependent manner. Our results demonstrate that reduced risk bioinsecticide products like spinosad can be more toxic to biological control agents than certain conventional insecticides.

The HDAC Inhibitors Scriptaid and LBH589 Combined with the Oncolytic Virus Delta24-RGD Exert Enhanced Anti-Tumor Efficacy in Patient-Derived Glioblastoma Cells.

BackgroundA phase I/II trial for glioblastoma with the oncolytic adenovirus Delta24-RGD was recently completed. Delta24-RGD conditionally replicates in cells with a disrupted retinoblastoma-pathway and enters cells via αvβ3/5 integrins. Glioblastomas are differentially sensitive to Delta24-RGD. HDAC inhibitors (HDACi) affect integrins and share common cell death pathways with Delta24-RGD. We studied the combination treatment effects of HDACi and Delta24-RGD in patient-derived glioblastoma stem-like cells (GSC), and we determined the most effective HDACi.MethodsSAHA, Valproic Acid, Scriptaid, MS275 and LBH589 were combined with Delta24-RGD in fourteen distinct GSCs. Synergy was determined by Chou Talalay method. Viral infection and replication were assessed using luciferase and GFP encoding vectors and hexon-titration assays. Coxsackie adenovirus receptor and αvβ3 integrin levels were determined by flow cytometry. Oncolysis and mechanisms of cell death were studied by viability, caspase-3/7, LDH and LC3B/p62, phospho-p70S6K. Toxicity was studied on normal human astrocytes. MGMT promotor methylation status, TCGA classification, Rb-pathway and integrin gene expression levels were assessed as markers of responsiveness.ResultsScriptaid and LBH589 acted synergistically with Delta24-RGD in approximately 50% of the GSCs. Both drugs moderately increased αvβ3 integrin levels and viral infection in responding but not in non-responding GSCs. LBH589 moderately increased late viral gene expression, however, virus titration revealed diminished viral progeny production by both HDACi, Scriptaid augmented caspase-3/7 activity, LC3B conversion, p62 and phospho-p70S6K consumption, as well as LDH levels. LBH589 increased LDH and phospho-p70S6K consumption. Responsiveness correlated with expression of various Rb-pathway genes and integrins. Combination treatments induced limited toxicity to human astrocytes.ConclusionLBH589 and Scriptaid combined with Delta24-RGD revealed synergistic anti-tumor activity in a subset of GSCs. Both HDACi moderately augmented viral infection and late gene expression, but slightly reduced progeny production. The drugs differentially activated multiple cell death pathways. The limited toxicity on astrocytes supports further evaluation of the proposed combination therapies.

The progesterone antagonist mifepristone/RU486 blocks the negative effect on life span caused by mating in female Drosophila.

Mating causes decreased life span in female Drosophila. Here we report that mifepristone blocked this effect, yielding life span increases up to +68%. Drug was fed to females after mating, in the absence of males, demonstrating function in females. Mifepristone did not increase life span of virgin females or males. Mifepristone reduced progeny production but did not reduce food intake. High-throughput RNA sequencing was used to identify genes up-regulated or down-regulated upon mating, and where the change was reduced by mifepristone. Five candidate positive regulators of life span were identified, including dosage compensation regulator Unr and three X-linked genes: multi sex combs (PcG gene), Dopamine 2-like receptor and CG14215. The 37 candidate negative genes included neuropeptide CNMamide and several involved in protein mobilization and immune response. The results inform the interpretation of experiments involving mifepristone, and implicate steroid hormone signaling in regulating the trade-off between reproduction and life span.

Grain Health Protectant Activity of Essential Oils against Infestation and Damage of Haricot Bean by Zabrotes subfasciatus (Boheman)

Experiments were conducted to evaluate the efficacy of essential oils extracted from Chenopodium ambrosioides (L.), Rosmarinus officinalis (L.), Eucalyptus globulus (Labill), Trachyspermum ammi (Sprague) and Cymbopogon citratus (Stapf) against Zabrotes subfasciatus (Boheman) (Coleoptera: Bruchidae) under laboratory condition (27±3°C, 50-70% RH ). The test insects were reared in glass jar and investigated on whole Awash-1 haricot bean variety grains. A standard insecticide, primiphos-methyl 5% dust and untreated control were included for comparison. The experiment was arranged in a completely randomized design in three replications. Essential oils from the above mentioned plants were admixed with the bean grains at the rate of 750 mg/150 g of seeds. The rate of primiphos-methyl was 0.125 g/150 g of seeds. The results showed that there was complete mortality (100%) of Z. subfasciatus adults within 24 hours after treatment due to C. ambrosioides, E. globulus, T. ammi and C. citratus. Application of essential oils to bean grains significantly reduced progeny production of Z. subfasciatus. Over 97% inhibition of F1 progeny production by the pest was recorded for all essential oil treatments at the highest dose of 750 mg. Application of essential oil extracts also significantly reduced the rates of haricot bean Original Research Article Degaga; AJEA, 9(1): 1-7, 2015; Article no.AJEA.16761 2 grain infestation (up to 100%) by Z. subfasciatus. Furthermore, essential oil extracts admixed to the bean grain proved to have no significant effects on the germination capacity of the treated haricot bean grains. From the current experiment it can be concluded that the tested botanicals are as effective as primiphos-methyl which gave 100% control of Z. subfasciatus and can be used for the management of the pest.

Aquaporins are critical for provision of water during lactation and intrauterine progeny hydration to maintain tsetse fly reproductive success.

Tsetse flies undergo drastic fluctuations in their water content throughout their adult life history due to events such as blood feeding, dehydration and lactation, an essential feature of the viviparous reproductive biology of tsetse. Aquaporins (AQPs) are transmembrane proteins that allow water and other solutes to permeate through cellular membranes. Here we identify tsetse aquaporin (AQP) genes, examine their expression patterns under different physiological conditions (blood feeding, lactation and stress response) and perform functional analysis of three specific genes utilizing RNA interference (RNAi) gene silencing. Ten putative aquaporins were identified in the Glossina morsitans morsitans (Gmm) genome, two more than has been previously documented in any other insect. All organs, tissues, and body parts examined had distinct AQP expression patterns. Two AQP genes, gmmdripa and gmmdripb ( = gmmaqp1a and gmmaqp1b) are highly expressed in the milk gland/fat body tissues. The whole-body transcript levels of these two genes vary over the course of pregnancy. A set of three AQPs (gmmaqp5, gmmaqp2a, and gmmaqp4b) are expressed highly in the Malpighian tubules. Knockdown of gmmdripa and gmmdripb reduced the efficiency of water loss following a blood meal, increased dehydration tolerance and reduced heat tolerance of adult females. Knockdown of gmmdripa extended pregnancy length, and gmmdripb knockdown resulted in extended pregnancy duration and reduced progeny production. We found that knockdown of AQPs increased tsetse milk osmolality and reduced the water content in developing larva. Combined knockdown of gmmdripa, gmmdripb and gmmaqp5 extended pregnancy by 4–6 d, reduced pupal production by nearly 50%, increased milk osmolality by 20–25% and led to dehydration of feeding larvae. Based on these results, we conclude that gmmDripA and gmmDripB are critical for diuresis, stress tolerance and intrauterine lactation through the regulation of water and/or other uncharged solutes.

Insecticidal activity of Poppy (Papaver somniferum L.) seed oil against cowpea weevil (Callosobruchus maculatus F.) in stored cowpea

In this study, the insecticidal effect of Poppy (Papaver somniferum) seed oil was investigated against Callosobruchus maculatus (Bruchidae) in cowpea, at different concentrations and exposure time. The Poppy seed oil at 2, 4, 6, 8 and 10 ml/kg was tested against adults of C. maculatus, and the mortality was counted after 24, 48 and 72 h of exposure. All tests were conducted at 27–30 °C and 65 ± 5% r.h. The experiments were carried out based on the factorial experiment by randomized complete design with four replications. Twenty-five insects with 0–24 h old were used for each replication. The effect of Poppy seed oil on the reduction of emergence of insects in next generation (F1) was also assayed. The results of experiments indicate the significant differences between concentrations and exposure time (p < 0.0001), and the increase of concentrations and exposure time increased mortality. The amount of mortality at high concentrations was remarkable, and highest mortality rate (96.91%) was recorded at 10 ml/kg, after 72 h of exposure. The application of oil significantly reduced F1 progeny production and even at lowest concentration (2 ml/kg), the amount of F1 production was reduced more than 70%, compared with control treatment. Complete (100%) reduction in progeny production was recorded at the rates of 8 and 10 ml/kg. The results of seed germination assay showed no significant differences between control and treated seed, and no harmful effect was observed on the seed germination. These results proved that Poppy seed oil can be used as a controlling agent of storage pests, especially C. maculatus, although more detailed studies are necessary.