Reduction In Progeny Research Articles

High concentrations of piperonyl butoxide (PBO) enhance toxicity of S-methoprene against the lesser grain borer, Rhyzopertha dominica.

Insect growth regulators (IGRs) have been playing a major role in the effective management of a range of stored product insect pests including species that have developed resistance to major groups of insecticides, such as organophosphates (OPs) and synthetic pyrethroids (SPs). In the present study, we evaluated the efficacy of S-methoprene alone and in combination with piperonyl butoxide (PBO), an adjuvant component of insecticides for synergy, against two strains, Lab-S (susceptible) and Met-R (Methoprene resistant) of an economically important pest species, the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae). Adults of both Lab-S and Met-R strains were exposed to wheat treated with multiple concentrations of S-methoprene ranging from 0.001 to 0.01 and 10 to 60 mg/kg, respectively, alone and in combination with PBO. A variety of concentrations, including 0.27, 0.53, 0.80, and 1.07 g/kg, were evaluated for PBO. Mortality of adults and percent reduction in progeny were assessed after 14 and 65 days of treatment, respectively. As anticipated, the adult mortality rates of both strains were not significantly affected by S-methoprene alone. However, the number of progeny produced confirmed that the Met-R strain exhibited a high level of resistance to S-methoprene alone, with over 50 F1 progeny adults surviving in wheat treated with the maximal rate, 10 mg/kg. In contrast, the toxicity of S-methoprene was increased against the same resistant strain (Met-R), by 0.80 or 1.07 g/kg of PBO in combination treatment, resulting in a significant reduction in progeny numbers (25 adults per container). Although the tested concentrations of S-methoprene and PBO were well above the currently registered rate globally, our results highlight the fact that PBO enhances the toxicity of S-methoprene to some extent, reaffirming that the mode of action of the latter involves the inhibition of mixed-function oxidases (MFOs) and highlights the need for further research into developing potential binary or triplet formulations containing these two active ingredients (AIs).

Chlamydia trachomatis induces disassembly of the primary cilium to promote the intracellular infection.

Chlamydia trachomatis is a clinically important bacterium that infects epithelial cells of the genitourinary and respiratory tracts and the eye. These differentiated cells are in a quiescent growth state and have a surface organelle called a primary cilium, but the standard Chlamydia cell culture infection model uses cycling cells that lack primary cilia. To investigate if these differences are relevant, we performed infections with host cells that have a primary cilium. We found that C. trachomatis caused progressive loss of the primary cilium that was prevented by disrupting Aurora A (AurA), HDAC6 or calmodulin, which are components of the cellular cilia disassembly pathway. Stabilization of the primary cilium by targeting this pathway caused a large reduction in infectious progeny although there were no changes in chlamydial inclusion growth, chlamydial replication or the ultrastructural appearance of dividing and infectious forms (RBs and EBs, respectively). Thus, the presence of a primary cilium interfered with the production of infectious EBs at a late step in the developmental cycle. C. trachomatis infection also induced quiescent cells to re-enter the cell cycle, as detected by EdU incorporation in S-phase, and Chlamydia-induced cilia disassembly was necessary for cell cycle re-entry. This study therefore describes a novel host-pathogen interaction in which the primary cilium limits a productive Chlamydia infection, and the bacterium counteracts this host cell defense by activating the cellular cilia disassembly pathway.

Efficiently Controlled <i>Callosobruchus maculatus</i> (F.) (Fam. Bruchidae) by Ultraviolet Ray or Microwave Energy in Conjugation with Pirimiphos-Methyl

This study aimed to explore novel approaches for effectively managing Callosobruchus maculatus while ensuring minimal impact on human health and the environment. The investigation involved exposing the insects to ultraviolet rays (254 nm) for 24 hours, which did not directly cause mortality in adult C. maculatus but led to a significant reduction in their progeny by 10%. The reduction in progeny further increased when insects were pre-exposed to a sublethal dose of actellic at LC25, resulting in a reduction of 39%. Additionally, ultraviolet rays exhibited a significant ovicidal effect, with hatchability reduced to 26% compared to 73% in the control group. Microwave exposure at a low energy level for 4-6 minutes demonstrated a significant acute lethal effect, reduced progeny, and ovicidal action. Combining microwaves with actellic at LC25 slightly enhanced the lethal effect. In conclusion, this study unveils promising strategies for the effective management of Callosobruchus maculatus, highlighting the potential of ultraviolet rays and microwave energy, either alone or in combination with actellic, while emphasizing the importance of minimizing adverse impacts on both human health and the environment.

The efficacy of some synthetic monoterpenes and Yucca extract for controlling Tribolium castaneum (Herbst) in wheat grain

The study’s objective was to assess the efficacy and to identify the toxic mechanisms of action of some plant-derived monoterpenes and yucca extract as alternatives to chemical insecticides against the red flour beetle, Tribolium castaneum. Carvone, 1,8-cineole, cuminaldehyde, and linalool, as well as Yucca schidgera extract, were the control agents whose efficacy against the red flour beetle was tested in the laboratory and compared to malathion. The criteria for evaluating efficacy were the effects of the tested compounds on adult mortality and red flour beetle progeny. Furthermore, the effects of the control agents on some enzymes (Acetylcholinesterase, ά-amylase, and alkaline phosphatase) in T. castaneum were investigated. Moreover, the effect of the tested control measures on weight loss of treated wheat grain was studied. The tested substances showed a high ability to control T. castaneum with regard to adult mortality and offspring production, especially when used as fumigants. For adult mortality, malathion showed the highest potential against T. castaneum as a fumigant, followed by carvone, yucca extract, cuminaldehyde, linalool, and 1,8-cineole with LC 50 values of 0.05, 331.5, 365.1, 372.2, 460, and 467.5 mg · 1000 cm –2 after 72 hours, respectively. The highest reduction in progeny was for malathion followed by carvone, linalool, cineole, yucca extract, and cuminaldehyde with reduction percentages of 100, 90, 89.3,79.4 and 65.8%, respectively. The tested compounds significantly affected acetylcholinesterase activity, alpha-amylase activity, and alkaline phosphatase in the red flour beetle. There was no significant reduction in the weight of wheat grains treated with the tested materials compared to the untreated healthy grains. Finally, the tested compounds as fumigants, especially 1,8-cineole, can be considered as effective alternatives to control the red flour beetle.

Coordinated transcriptional response to environmental stress by a Synechococcus virus.

Viruses are a major control on populations of microbes. Often, their virulence is examined in controlled laboratory conditions. Yet, in nature, environmental conditions lead to changes in host physiology and fitness that may impart both costs and benefits on viral success. Phosphorus (P) is a major abiotic control on the marine cyanobacterium Synechococcus. Some viruses infecting Synechococcus have acquired, from their host, a gene encoding a P substrate binding protein (PstS), thought to improve virus replication under phosphate starvation. Yet, pstS is uncommon among cyanobacterial viruses. Thus, we asked how infections with viruses lacking PstS are affected by P scarcity. We show that the production of infectious virus particles of such viruses is reduced in low P conditions. However, this reduction in progeny is not caused by impaired phage genome replication, thought to be a major sink for cellular phosphate. Instead, transcriptomic analysis showed that under low P conditions, a PstS-lacking cyanophage increased the expression of a specific gene set that included mazG, hli2, and gp43 encoding a pyrophosphatase, a high-light inducible protein and DNA polymerase, respectively. Moreover, several of the upregulated genes were controlled by the host's phoBR two-component system. We hypothesize that recycling and polymerization of nucleotides liberates free phosphate and thus allows viral morphogenesis, albeit at lower rates than when phosphate is replete or when phages encode pstS. Altogether, our data show how phage genomes, lacking obvious P-stress-related genes, have evolved to exploit their host's environmental sensing mechanisms to coordinate their own gene expression in response to resource limitation.

Long term efficacy of three chitin synthesis inhibitors and oxymatrine as ecofriendly seed protectants against Callosobruchus maculatus and Callosobruchuschinensis

The residual efficacy of three chitin synthesis inhibitors (CSIs) (chlorfluazuron, hexaflumuron and lufenuron) and oxymatrine at an application rate of 5.0 mg/kg was evaluated against Callosobruchus maculatus and Callosobruchus chinensis monthly for 5 consecutive months (6 bioassays). In each bioassay, the mortality of two insect adults was counted after 7 days, progeny reduction and cowpea weight loss percentages were recorded after 45 days. Our results revealed that CSIs caused high level of adult mortality of both insects and oxymatrine caused a complete adult mortality (100%) for five months storage. The tested CSIs produced a significant progeny reduction of C. maculatus and C. chinensis but did not achieve a complete reduction of F1 progeny during all storage periods. A complete progeny suppression of two insects and full cowpea seed protection were observed in all oxymatrine treatments during the entire storage periods. A remarkable protection of cowpea seeds was also achieved in the treatments with CSIs particularly chlorfluazuron during the first 3 months. These findings indicate CSIs and oxymatrine could be implemented in integrated pest management programs of both insect species.

Evaluating the Compatibility of Spinosad and Alpha-Cypermethrin for Controlling Six Insect Pests Infesting Stored Wheat.

The deterioration of stored wheat due to pest infestations is a significant concern, with pests like Rhyzopertha dominica, Tribolium castaneum, Cryptolestes ferrugineus, Sitophilus oryzae, Oryzaephilus surinamensis, and Trogoderma granarium being major contributors. This study examined the efficacy of spinosad and alpha-cypermethrin, individually and in combination, against these pests under laboratory conditions. Spinosad was tested at two concentrations (0.05 and 0.1 mg/kg), while alpha-cypermethrin was applied at 0.05 mg/kg. The combined application of both insecticides led to significantly higher pest mortality compared to single treatments. Importantly, all treatments caused substantial pest mortality and exhibited the ability to suppress pest progeny production over time, as observed in both laboratory and persistence trials. Among the various treatment combinations, the joint application of 0.1 mg/kg spinosad and 0.05 mg/kg alpha-cypermethrin emerged as the most effective, resulting in elevated mortality and a marked reduction in pest progeny. Rhyzopertha dominica exhibited the highest susceptibility among the pests, followed by S. oryzae, T. castaneum, C. ferrugineus, O. surinamensis, and T. granarium. The remarkable performance of the joint action of alpha-cypermethrin and spinosad at low doses highlights this combination as an efficacious approach for safeguarding stored grain against these destructive insect pests, warranting further exploration.

Entomopathogenic fungi as potential biocontrol agents against Callosobruchus maculatus (F.) and Callosobruchus chinensis L. (Coleoptera: Chrisomelidae: Bruchinae) on stored cowpea seeds

The insecticidal efficacy of four species of Trichoderma genius (T. harzianum, T. citrinoviride, T. viride and T. asperellum) and Metarhizium anisopliae was assessed against Callosobruchus maculatus and C. chinensis on cowpea seeds at concentrations of 2.0 × 106, 2.0 × 107, 2.0 × 108 and 2.0 × 109 conidia/kg. The adult mortality was counted 3 and 7 days after treatment while progeny and seed weight loss were recorded after 45 days. After 7 days, all fungal strains caused significant adult mortality of both insects particularly at 2.0 × 109 spores/kg. Metarhizium anisopliae and T. citrinoviride were the most effective fungi inducing 95 and 93.2% mortalities of C. chinensis at 2.0 × 109 spores/kg, respectively. Callosobruchus chinensis was slightly more susceptible to the fungal strains than C. maculatus. Furthermore, the fungal strains at the highest concentration caused a significant reduction in F1 progeny of both insects. After 45 days, T. harzianum at 2.0 × 109 spores/kg showed the highest protection of cowpea seeds against C. chinensis with weight loss of 6.5%. These findings indicate that the five fungal strains could be implemented in integrated pest management programs of these insects.

Persistence and residual efficacy of abamectin and spinosad for control of Callosobruchus maculatus and Callosobruchus chinensis on stored cowpea seeds

Residual toxic effect of insecticides mixed with or sprayed on stored commodities is a key element of an efficient protection of stored products. The residual efficacy of chlorprifos-methyl, deltamethrin, abamectin and spinosad at application rates of 5.0, 2.0, 2.0 and 1.0 mg/kg, respectively, was tested against Callosobruchus maculatus and C. chinensis on cowpea seeds for five consecutive months (6 bioassays). In each bioassay, the mortality of adults was counted after 7 days, and progeny reduction and cowpea weight loss percentages were recorded after 45 days. Our results revealed that the insecticides caused remarkable adult mortality of two insects for five months storage. Abamectin (2.0 mg/kg) was the most effective insecticide with 96.4–100.0% and 84.4–100.0% adult mortality of C. maculatus and C. chinensis, respectively, during 2 to 5-month period of storage. A gradual decline of mortality was noted over the 3-month period of storage in all insecticide treatments except for abamectin. Complete progeny suppression (100%) of the two insects was observed in abamectin treatments particularly at the first 3 months of storage. While in the case of chlorprifos-methyl, the maximum inhibition of progeny of C. maculatus (9.4 ± 3.5) and C. chinensis (7.2 ± 2.2) was achieved after 45 days of exposure in the first bioassay (0 month), then the progeny of two insects was increased with increasing the storage periods (1–5 months). Moreover, deltamethrin and spinosad did not induce a complete reduction of progeny of two insects during all storage periods. High protection of cowpea seeds against damage caused by two bruchid insects after 45 days of exposure was achieved in all abamectin treatments for five months and chlorprifos-methyl treatments at 0 month. Overall, abamectin demonstrates better residual efficacy than other insecticides over 5-month storage period against C. maculatus and C. chinensis and it could be a useful candidate for protection of stored cowpea seeds.

An allosteric inhibitor of sirtuin 2 deacetylase activity exhibits broad-spectrum antiviral activity.

Most drugs used to treat viral disease target a virus-coded product. They inhibit a single virus or virus family, and the pathogen can readily evolve resistance. Host-targeted antivirals can overcome these limitations. The broad-spectrum activity achieved by host targeting can be especially useful in combating emerging viruses and for treatment of diseases caused by multiple viral pathogens, such as opportunistic agents in immunosuppressed patients. We have developed a family of compounds that modulate sirtuin 2, an NAD+-dependent deacylase, and now report the properties of a member of that family, FLS-359. Biochemical and x-ray structural studies show that the drug binds to sirtuin 2 and allosterically inhibits its deacetylase activity. FLS-359 inhibits the growth of RNA and DNA viruses, including members of the coronavirus, orthomyxovirus, flavivirus, hepadnavirus, and herpesvirus families. FLS-359 acts at multiple levels to antagonize cytomegalovirus replication in fibroblasts, causing modest reductions in viral RNAs and DNA, together with a much greater reduction in infectious progeny, and it exhibits antiviral activity in humanized mouse models of infection. Our results highlight the potential of sirtuin 2 inhibitors as broad-spectrum antivirals and set the stage for further understanding of how host epigenetic mechanisms impact the growth and spread of viral pathogens.

Comparative Efficacy of Phenol Concentration against Rhyzopertha dominica (F.) in Some Hulled Barley Cultivars Productivity and Grain Quality

Barley is an important food crop particularly for animal feeding and human food over the word, which infested by Rhyzopertha dominica (F.) insects at stored grain stage. Using modern methods of protection of stored grains from insect pests within integrated management (IPM) programs is an important approach. Ten hulled Egyptian barley cultivars were grown at Sakha Agricultural research station farm during two growing seasons 2020/ 2021 and 2021/ 2022 to evaluated their susceptible to R. dominica after 180 days from seeds storage. The influence of using phenol application on R. dominica and chemical properties of the barley grain were evaluated. The results showed that the barley cultivars (Giza123, Giza 2000, Giza137 and Giza138) were the lowest cultivars infested by R. dominica, which showed least reduction of weight loss and least percentage of grain infestation. Positive significant correlation was found among all insect infestation traits with protein content and total carbohydrates content. The loadings of principal component analysis PCA described about 96.4 % of the total variability of all studied traits. The heatmap cluster analysis, clustered all the ten hulled barley into two major clusters based on their productivity, grain quality and R. dominica infestation characters. Using phenol concentration of (0.4 g ai / kg) exhibited high toxic for R. dominica insect, showed lower LC50 values for Giza 132, Giza2000, Giza137 and Giza138 by (1.80, 2.08, 2.60, and 2.60 g ai / kg grains), high response index percentage (100.00, 85.50, 69.23 and 69.23%) with complete reduction of adult progeny of R. dominica after 120 hrs. of exposure. The technological quality of barley cultivars grains haven’t showing any significant change after treated with different phenol treatments.

Honokiol and Alpha-Mangostin Inhibit Mayaro Virus Replication through Different Mechanisms.

Mayaro virus (MAYV) is an emerging arbovirus with an increasing circulation across the Americas. In the present study, we evaluated the potential antiviral activity of the following natural compounds against MAYV and other arboviruses: Sanguinarine, (R)-Shikonin, Fisetin, Honokiol, Tanshinone IIA, and α-Mangostin. Sanguinarine and Shikonin showed significant cytotoxicity, whereas Fisetin, Honokiol, Tanshinone IIA, and α-Mangostin were well tolerated in all the cell lines tested. Honokiol and α-Mangostin treatment protected Vero-E6 cells against MAYV-induced damage and resulted in a dose-dependent reduction in viral progeny yields for each of the MAYV strains and human cell lines assessed. These compounds also reduced MAYV viral RNA replication in HeLa cells. In addition, Honokiol and α-Mangostin disrupted MAYV infection at different stages of the virus life cycle. Moreover, Honokiol and α-Mangostin decreased Una, Chikungunya, and Zika viral titers and downmodulated the expression of E1 and nsP1 viral proteins from MAYV, Una, and Chikungunya. Finally, in Honokiol- and α-Mangostin-treated HeLa cells, we observed an upregulation in the expression of type I interferon and specific interferon-stimulated genes, including IFNα, IFNβ, MxA, ISG15, OAS2, MDA-5, TNFα, and IL-1β, which may promote an antiviral cellular state. Our results indicate that Honokiol and α-Mangostin present potential broad-spectrum activity against different arboviruses through different mechanisms.

Microbial mutualism suppression by Trichoderma and Bacillus species for controlling the invasive ambrosia beetle Xylosandrus compactus

Xylosandrus compactus (Eichhoff) (Coleoptera: Curculionidae: Scolytinae) is among the most invasive ambrosia beetles causing severe damage to host plants belonging to various ecosystems. Foundress females excavate galleries into the plant xylem introducing mutualistic ambrosia fungi which are the exclusive food source for their offspring. The cryptic habits of this fungus-farming insect and its wide host range facilitated its rapid spreading worldwide. Despite several advances in deepening the bio-ecology of this beetle, there is still a general lack of information about effective control strategies. In this context, microbials, such as antagonistic bacteria and mycoparasitic fungi, can have the potential to act as alternative management tools. Here, we evaluated, for the first time, the potential of commercially available microbial agents for suppressing the growth of the main beetle mutualist, Ambrosiella xylebori, and consequently to hamper the beetle progeny development. The antagonistic activity of five Trichoderma and two Bacillus-based biofungicides was first evaluated in vitro by means of dual-culture experiments in Petri dishes. Then, beetle bioassays were conducted by exposing carob twigs, previously treated with different concentrations of each biofungicide, to beetle foundresses. Tested microbial antagonists significantly suppressed the growth of A. xylebori on Petri dishes. A significant reduction of the beetle progeny was observed in galleries of treated twigs compared to controls. The higher reduction in mutualist growth and brood production was obtained within galleries of T. atroviride treated twigs. Our results show the potential of the tested microbials to suppress the beetle mutualist growth within galleries and consequently to affect the development of its progeny.

MOLECULAR EVALUATION AND PHENOL APPLICATION EFFECTS ON BARLEY INFESTATION BY Rhyzopertha dominica (F.)

Food safety has been a challenge for many years owing to pre and post-harvest losses of agricultural products in the word. In this study, twelve barley cultivars were used to evaluate grain yield, quality parameters and insect pest (Rhyzopertha dominica (F.) infestation using Sequence-Related Amplified Polymorphism (SRAP) marker analysis to study the genetic diversity among the 12 cultivars and Phenol as a chemical application such as modern methods of stored grains protection. SRAP markers confirm that there were highly genetic information differences among all cultivars and their response to insect pest (R. dominica (F.). High polymorphism (83%) and high Polymorphic information content (PIC) (0.84%) was found by primer (me6+em6). The dendrogram of SRAP markers had clustered all the cultivars into two major groups based on their genetic information which could use them in cultivar identification breeding for insect pest control. All the hulless barley had high protein and low phenol content and was more susceptible to R. dominica. Application of the phenol concentration (0.4 g ai/kg) in all the test hulless grain showed high mortality percentages after five days of exposure also caused complete reduction of adult progeny of insect Giza 135 and least damage of grains as lowest Lethal Concentration 50% (LC50%) was 0.33 g ai/kg grain. Moreover, there is no change were found in technological grain properties, thus using phenol will e a positive feature integrated pest management (IPM) programs.

Insecticidal and acetylcholinesterase inhibitory activities of Achillea biebersteinii essential oil and its nanoemulsion and major monoterpenes against Tribolium castaneum

• EO of Achillea biebersteinii was obtained and analyzed using (GC–FID) and (GC–MS). • Oil-in-water nanoemulsion was prepared and characterized from EO. • EO, nanoemulsion and monoterpenes were insecticidal and reduced T . castaneum progeny. • Botanicals significantly inhibited the larval acetylcholinesterase activity. • There is potential for using the test EO products as natural grain protectants. Essential oil (EO) was hydrodistilled from Achillea biebersteinii and analyzed using gas chromatography–flame ionization detection (GC–FID) and (GC–MS). Three monoterpenes, α-terpinene, p -cymene, and camphor were isolated as the main terpenes in the EO. Oil-in-water nanoemulsion (particle size 52.7 ± 4.4 nm) was prepared and characterized from EO through a hydrothermal approach. The EO products caused insecticidal effects and altered F 1 progeny of the red flour beetle, Tribolium castaneum (Herbst) in a dose and exposure time-dependent manner. The nanoemulsion was superior in bioactivity, followed EO. At 12.5 µl/cm 2 , nanoemulsion and EO caused 100% mortality of the second larvae after 4 days of exposure with reduction of F 1 progeny of 100.0 and 89.2%, respectively. At 50.0 µl/cm 2 , percentage mortality and reduction in progeny of EO products ranged between (61.4–100%) and (53.0–100%), respectively. Upon fumigation, nanoemulsion at 10 µl/L air caused 100% mortality of the second larvae after 4 days of exposure. At 20 µl/L air and 4 days after treatment, percentage mortality with the remainder botanicals ranging between 64.7 and 100. LC 50 ′s of products after 48 h exposure ranging between 6.7 and 58.1 µg/cm 2 in insecticidal bioassay, and between 3.6 and 26.3 µl/L upon fumigation. Botanicals caused a remarkable inhibition of acetylcholinesterase activity (AChE), where nanoemulsion (IC 50 = 14.22 mM), EO (IC 50 = 35.12 mM) and camphor (IC 50 = 23.93 mM) were superior as AChE inhibitors. There is a potential for using of A. biebersteinii EO, its nanoemulsion and monoterpenes as natural grain protectants after the required toxicological investigations.

Bioactivity of Some Botanical Powders Against Wheat Weevil, Sitophilus granarius (L.) (Coleoptera: Curculionidae), and Confused Flour Beetle, Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae)

Stored-product pests attack cereal grains and legume seeds post-harvest. They not only damage the grain but also decrease its weight and quality. Therefore, the aim of the present study was to investigate the bioactivity of resin powders extracted from Pistacia lentiscus L. bark, Boswellia carterii birdwood bark, and Elettaria cardamomum seeds against two of the most important stored-product pests, Sitophilus granarius (L.) and Tribolium confusum Jacquelin du Val. We used three bioassay methods, repellent effect, reduction of progeny, and grain weight loss and investigated the effects of the powders on the life cycles of the insects. Wheat grains were mixed with the three botanical powders separately, at different concentrations (3, 5, 7, and 10 % w/w). Sitophilus granarius and T. confusum were fed these mixtures. Repellent activity was examined after 2, 4, 8, 12, and 24 h. The E. cardamomum powder displayed the maximum repellent activity (100 %) against both S. granarius and T. confusum after 24 h at 3 % concentration. The P. lentiscus powder reached maximum repellent activity (80 %) against S. granarius and T. confusum at 7 % concentration after 12 h and 24 h, respectively. The B. carterii powder achieved maximum repellent activity against S. granarius and T. confusum (73.3 % and 86.7 %) at 10 % concentration after 24 h and 12 h, respectively. No progeny was produced in grains treated with 3 % P. lentiscus powder, 7 % E. cardamomum powder, or 7 % B. carterii powder. Thus, protection against both beetles started from 3 % concentration when P. lentiscus powder was used and from 7 % and 10 % (against S. granarius and T. confusum, respectively) when E. cardamomum powder was used. A 7 % B. carterii concentration completely saved the grains from S. granarius damage, and a 10 % concentration offered 99.5 % protection against T. confusum. However, all tested powders significantly affected all the studied parameters (life cycle and grain weight loss). The results show that the three botanical powders provide high repellent activity against S. granarius and T. confusum, which might be useful in protecting stored grains from these insects.

Novel Sterile Insect Technology Program Results in Suppression of a Field Mosquito Population and Subsequently to Reduced Incidence of Dengue.

There is a steady rise in the global incidence of Aedes-borne arbovirus disease. It has become urgent to develop alternative solutions for mosquito vector control. We developed a new method of sterilization of male mosquitoes with the goal to suppress a local Aedes aegypti population and to prevent the spread of dengue. Sterile male mosquitoes were produced from a locally acquired Ae. aegypti colony by using a treatment that includes double-stranded RNA and thiotepa. A field study was conducted with sterile mosquito releases being performed on a weekly basis in predefined areas. There were 2 intervention periods (INT1 and INT2), with treatment and control areas reversed between INT1 and INT2. During INT1, releases in the treated area resulted in up to 91.4% reduction of live progeny of field Ae. aegypti mosquitoes recorded over time, while the control neighborhoods (no releases of sterile male mosquitoes) remained highly infested. The successful implementations of the program during INT1 and INT2 were associated with 15.9-fold and 13.7-fold lower incidences of dengue in the treated area compared to the control areas, respectively. Our data show the success of this new sterile insect technology-based program in preventing the spread of dengue.

The mycotoxin beauvericin impairs development, fertility and life span in the nematode Caenorhabditis elegans accompanied by increased germ cell apoptosis and lipofuscin accumulation

Beauvericin is an ubiquitous mycotoxin with relevant occurrence in food and feed. It causes a high toxicity in several cell lines, but its general mechanism of action is not fully understood and only limited in vivo studies have been performed. We used Caenorhabditis elegans as a model organism to investigate effects of beauvericin. The mycotoxin displays a moderate acute toxicity at 100 μM; at this concentration also reproductive toxicity occurred (reduction of total progeny to 32.1 %), developmental toxicity was detectable at 250 μM. However, even lower concentrations were capable to reduce stress resistance and life span of the nematode: A significant reduction was detected at 10 μM beauvericin (decrease in mean survival time of 4.3 % and reduction in life span of 12.9 %). An increase in lipofuscin fluorescence was demonstrated starting at 10 μM suggesting oxidative stress as a mechanism of beauvericin toxicity. Beauvericin (100 μM) increases the number of apoptotic germ cells comparable to the positive control UV-C (400 J/m2). Conclusion: Low concentrations of beauvericin are capable to cause adverse effects in C. elegans, which may be relevant for hazard identification of this compound.

Evaluation of diatomaceous earth formulations enhanced with natural products against stored product insects

The insecticidal effect of prepared insecticide formulations labelled as Natural P, Inert Natural P and Py EC on Sitophilus oryzae, Rhyzopertha dominica and Tribolium castaneum have been evaluated on wheat grains. Formulation Natural P contains diatomaceous earth (DE), amorphous silica gel (3%), pyrethrin, flax oil, lavandin essential oil (EO) and un-activated yeast. Formulation Inert Natural P contains DE, amorphous silica gel, lavandin EO and food grade bait whereas formulation Py EC contains pyrethrin, piperonyl butoxide (PBO), flax oil, polysorbate, methyl oleate and amorphous silica gel (5%). Celatom® MN-51 (diatomaceous earth – DE) was used as a standard insecticide. Inert Natural P and Natural P were applied as dust at four different doses and Py EC was applied as emulsions on grain by spraying. All three formulations showed higher insecticidal efficacy and higher progeny inhibition on all three tested insect species and had lower impact on wheat bulk density reduction compared with Celatom® MN-51. The LD50 and LD90 values of Inert Natural P were 48.7 and 163.7 ppm respectively for S. oryzae, 15.2 and 178.0 ppm for R. dominica and 115.2 and 171.3 ppm for T. castaneum. The LD50 and LD90 values of Natural P were 83.6 and 97.9 ppm respectively for S. oryzae, 19.5 and 97.9 ppm for R. dominica and 75.4 and 105.6 ppm for T. castaneum. Applied Py EC at concentration of 2.0 ppm a.i. pyrethrin exhibited 100% mortality after 2 d of S. oryzae and T. castaneum and after 6 d of R. dominica. In addition, all three formulations caused significant reduction of progeny (F1) population compared to control, providing promising approach of integrated pest management strategy.

USING THERMAL TREATMENT TO ELIMINATE COWPEA BEETLE CALLOSOBRUCHUS MACULATUS (F.) INFESTING FABA BEAN DURING STORAGE AND ITS EFFECT ON THE PHYSIOCHEMICAL AND TECHNOLOGICAL PROPERTIES

Thermal disinfestations consider one of the methods of physical insect control. Eggs, larvae, pupae, and adults of callosobruchus maculates were introduced at 50,60,70 and-5, -10oC for varying durations 5,10,15,30,45,60,75 and 90 min. Results indicated that, adults survival decreased with exposure times increase, complete mortality was achieved at 50,60 and 70oC for 50,40 and 30 min. of exposure times respectively. On the other hand, highly sensitive due to low temperature was recorded at -10oC followed by -5oC within 25 and 30 min. respectively, which resulted in complete mortality. So, the degree of -10oC resulted in preventing any hatch and development of eggs, any emergence for all immature stages after 45 min. then, the reduction of progeny was 100%. Due to the above mentioned results, treatments of 60oC and -10oC for 75 and 45 min. respectively, were selected to evaluate the physiochemical and technological properties. Results indicated that the color of control and treated faba bean at low and high temperature indicated that both high and control samples L value significantly decreased (p > 0.05), a value increased after treated with high temperature while, b value increased in low temperature treated seeds. Protein content showed no significant differences of both low and high temperature and control. Cookability of seeds and protein digestibility were higher in high temperature samples than low temperature treated seeds and control. On other hand, bioactive compounds (phytic acid, tannins and total phenols) reduced in high temperature compared with low temperature treated seeds and control sample. Sensory evaluation of cooked faba bean showed non significant differences in all sensory parameters compared with control. Finally, it could be said that the thermal treatments of legumes is one of the best physical methods used to kill the insects of legumes and their stages and thus keep the seeds also maintaining its physicochemical properties and did not cause loss of protein.