Isolation of Beauveria Strains and Their Potential as Control Agents for Lema bilineata Germar (Coleoptera: Chrysomelidae)

Lema bilineata Germar (Coleoptera: Chrysomelidae) was recently reported to damage Physalis peruviana crops in Brazil. Given the potential for inflicting damage on other Solanaceae species and the lack of alternatives for controlling this pest, we assessed the pathogenicity of 15 Beauveria isolates against L. bilineata adults in vitro. In addition, three of these isolates were tested for their ovicidal effect against L. bilineata eggs. Fungal strains were isolated from mummified corpses of L. bilineata collected in a non-commercial field in Paraná, Brazil. The isolates were identified as Beauveria bassiana using molecular markers. Lema bilineata adults were susceptible to conidial suspensions of all these isolates at a concentration of 108 conidia mL−1. Deaths caused by fungal extrusion were confirmed. Three strains were found to be more virulent against L. bilineata adults and showed ovicidal effects. This is the first study on entomopathogenic fungi isolated from dead insects collected from P. peruviana crops and tested against L. bilineata carried out in Brazil. The results obtained in the laboratory indicate the high potential of the use of three B. bassiana strains against L. bilineata as a biocontrol agent.

Oviposition Deterrence and Ovicidal Activity of Birbira (Melletia furrgunia) on Diamondback Moth (Plutella xylostella) (Lepidoptera: Plutellidae)

The efficacy of different polar and non-polar solvent extracts of Birbira, Melletia furrginea (Hochst.) Baker tree seeds namely: Water, Acetic acid, Acetone, Chloroform, Toluene, and Hexane at different rates were evaluated on Diamondback moth, Plutella xylostella L. oviposition and egg mortality under laboratory conditions. The leaf dipping method was used to run both assays. In the assay, full Oviposition deterrence was recorded at the higher rates of polar solvent extracts. Significantly higher egg un-hatchability was recorded only at the higher rates for non-polar extracts. Eggs mortality caused by extracts with Water and Acetone was very high, and have much smaller LC50 values. In contrast, LC50 was higher for the other extracts. However, there was a constant increase in the percent kill of egg mass with the increase in the extract concentration. From this study, it is evident that M. furrgunia extracts with different solvents possess significant oviposition deterrence and ovicidal effect on P. xylostella.

Biocidal Activity of a Nanoemulsion Containing Essential Oil from Protium heptaphyllum Resin against Aedes aegypti (Diptera: Culicidae)

This work aimed to prepare a nanoemulsion containing the essential oil of the Protium heptaphyllum resin and evaluate its biocidal activities against the different stages of development of the Aedes aegypti mosquito. Ovicide, pupicide, adulticide and repellency assays were performed. The main constituents were p-cymene (27.70%) and α-pinene (22.31%). The developed nanoemulsion showed kinetic stability and monomodal distribution at a hydrophilic–lipophilic balance of 14 with a droplet size of 115.56 ± 1.68 nn and a zeta potential of −29.63 ± 3.46 mV. The nanoemulsion showed insecticidal action with LC50 0.404 µg.mL−1 for the ovicidal effect. In the pupicidal test, at the concentration of 160 µg.mL−1, 100% mortality was reached after 24 h. For adulticidal activity, a diagnostic concentration of 200 µg.mL−1 (120 min) was determined. In the repellency test, a concentration of 200 µg.mL−1 during the 180 min of the test showed a protection index of 77.67%. In conclusion, the nanobiotechnological product derived from the essential oil of P.heptaphyllumresin can be considered as a promising colloid that can be used to control infectious disease vectors through a wide range of possible modes of applications, probably as this bioactive delivery system may allow the optimal effect of the P. heptaphyllum terpenes in aqueous media and may also induce satisfactory delivery to air interfaces.

Lethal and sublethal effects of Azadirachta indica-based products on Tetranychus neocaledonicus (Acari: Tetranychidae)

The objective of this study is to evaluate the toxicity, repellency, and the ovicidal, residual, and sublethal effects of different neem-based commercial formulations on the red mite Tetranychus neocaledonicus André (1933) reared in the laboratory on lima bean (Phaseolus lunatus L.). To evaluate the toxicity on adult females of T. neocaledonicus, different concentrations of Natural Neem® (NN), Off-Neem® (ON), Nim-I-GO® (NG), and Azamax® (AZ) were defined from preliminary tests. The mortality and toxicity ratio were evaluated 48 h after application of the lethal concentrations (LC50s and LC95s). The repellent effect was verified through a two-choice test. The concentration used was the LC50 of the products calculated in the toxicity test. The number of mites attracted, the repellency index (RI), and the percentage of repellency of each product were calculated. The ovicidal effect after application of the LC50s and LC95s of each product and egg viability were observed. To evaluate the residual efficiency, the plants were sprayed with LC50 and LC95 of the products and the leaves were subsequently harvested at 24, 48, and 96h after the application of the products to evaluate mortality and oviposition reduction (PR - percentage of reduction). The sublethal effects were evaluated by applying the LC30 of the products (AZ, NG) to newly emerged females, whose survival and oviposition were evaluated daily. The determined LC50s were 0.39; 0.48; 0.68; and 1.39% for AZ, ON, NN, and NG, respectively. Considering the LC50, AZ was the most toxic product followed by ON, whereas the established LC95s were 2.20; 3.74; 6.10; and 7.98% for NN, ON, AZ, and NG, respectively. All tested products were classified as repellents for adult females of T. neocaledonicus. The eggs of T. neocaledonicus treated with the LC95s of the products had their viabilities inhibited. However, when using the LC50s, NN provided the lowest viability (8.0%), being considered the most toxic for eggs. The products presented reduced residual effect probably due to their rapid degradation. The mites treated with sublethal concentrations showed an average survival in days of 25.43, 28.35, and 29.20 for the treatments with Azamax®, control (untreated), and Nim-I-GO®, respectively. Relatively high oviposition rates in the first weeks decreased until the end of their life cycle. The life history of T. neocaledonicus is affected by sublethal concentrations of neem-based products. It was concluded that the tested products demonstrated acaricidal potential in the control of T. neocaledonicus on P. lunatus, presenting toxicity and repellent and ovicidal effect, although residual and sublethal effects were less significant.

Pathogenicity induced by indigenous Beauveria bassiana isolate in different life stages of the cotton leafworm, Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) under laboratory conditions

Background The invincible effects of the entomopathogenic fungi (EPF) under appropriate circumstances compensate for the flaws of chemical insecticides in the control programs. Beauveria bassiana is one of the most elaborated EPF of pest control all over the world. The potential of using the B. bassiana isolate (Y-F_ITS1) was examined against different larval instars (L2, L3, L4, and L5), pupae, and eggs of the cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae), using different concentrations under laboratory conditions. Results In bioassay, 2nd instar larvae of S. littoralis were significantly the most susceptible stage to B. bassiana isolate at P ≤ 0.05. It is apparent from the results that the cumulative mortality percentage increased with elapsing time with typical symptoms of infection and sporulation. High efficacies ranging from 85.0 to 99.0% corrected mortality rates were recorded for 2nd instar larvae at the spore concentration (1 × 109 spores ml−1). The mortality percentage reached 90.0% for the 3rd instar larvae treated with the same concentration after 5 days. The least mortality rates results were recorded at the 5th instar larvae. B. bassiana isolate showed an ovicidal effect to the eggs of S. littoralis that reached 100% mortality when treated with 1.0 × 108 and 1.0 × 109 spores ml−1, while the concentration 1 × 107 and 1.0 × 108 caused 65.0 and 87.0%, respectively. Reduction of adult emergence reached (0%) in case of treatment with the highest concentrations (1 × 108 and 1 × 109 spores ml−1). Morphogenetic abnormalities were also recorded. Conclusion Results of mortality rates and lethal concentration values resulted from the experiments indicated that the tested Y-F_ITS1 isolate was efficient and can be recommended as a potential biocontrol agent against S. littoralis. Further field evaluations are still needed.

Ovicidal action of insectoacaricide drugs sentry home, Neostomazan 1:200 manufacured by CEVA, Neostomazan 1:200 manufacured by product and Extrazol M on fleas Ctenocephalides spp. eggs

The aim of the research. To compare the ovicidal efficiency of insectoacaricides of different composition and manufacturers on flea eggs (Ctenocephalides spp.) for treatemnt of the premises where animals live. Materials and methods of the research. The study was conducted on the basis of the clinic of veterinary medicine "Vetservice" Sumy, laboratory "Veterinary Pharmacy" and "Innovative technologies and safety and quality of livestock products" of Sumy National Agrarian University. The ovicidal effect of insectoacaricides on flea eggs of Ctenocephalides spp. was studied. Ctenocephalides spp. eggs were selected from the pet bedding on which the animal spended most of its time, namely the cats. The studied material was selected with a cosmetic brush. Ctenocephalides spp. eggs were placed into a Petri dish of 10 eggs per each dish. The test material was introduced with a dental probe. There were 4 test dishes, which were treated with insectoacaricides (each test dish was treated with a separate drug) and 1 control dish with no treatment. Microscopy was conducted under a light microscope with magnification X8 of each egg, with following treatment of each egg with insectoacaricides. Monitoring was conducted in 24, 48 and 72 hours after treatment. Results. Research has shown that drugs which demonstrated 100 % ovicidal effectiveness were Sentry Home (pyriproxyfen – 0.02 %, permethrin – 0.2 %, n-Octyl Bicyclohepten – 1.0 %) in 24 hours and Neostomazan (CEVA)(transmix – 5.0 g, tetramethrin – 0.5 g) in 72 hours. Conclusions. Insectoacaricide drug Sentry Home (pyriproxyfen – 0.02 %, permethrin – 0.2 %, n-Octyl Bicyclohepten – 1.0 %), used for the treatment of the premises where the animals live, showed the most pronounced ovicidal effect in 24 hours.

Electrophysiological, Behavioural and Biochemical Effect of Ocimum Basilicum Oil and Its Constituents Methyl Chavicol and Linalool on Musca Domestica L.

The Ocimum basilicum essential oil (EO) was evaluated for its biological effect on M. domestica. Characterization of O. basilicum EO revealed the presence of methyl chavicol (70.93%), linalool (9.34%), epi-α-cadinol (3.69 %), methyl eugenol (2.48%), γ-cadinene (1.67%), 1,8-cineole (1.30%) and (E)-β-ocimene (1.11%). The basil EO and its constituents methyl chavicol and linalool caused the neuronal response in female adults of M. domestica. Adult female flies showed reduced preference to food source laced with basil EO and methyl chavicol. Substrate treated with EO and methyl chavicol at 0.25% caused an oviposition deterrence of over 80%. The ovicidal effect was high in O. basilicum EO (EC50 9.74mg/dm3) followed by methyl chavicol (EC50 10.67mg/dm3) and linalool (EC50 13.57mg/dm3. On contact toxicity, adults exposed to EO (LD50 10.01 μg/adult) were more susceptible than to methyl chavicol and linalool (LD50 13.62 μg/adult and LD50 43.12 μg/adult respectively). EO and its constituents methyl chavicol and linalool induced the detoxifying enzymes Carboxyl esterase (Car E) and Glutathione S – transferases (GST)

Systematic Phytochemical Screening of Different Organs of Calotropis procera and the Ovicidal Effect of Their Extracts to the Foodstuff Pest Cadra cautella

In developing countries, crop deterioration is mainly caused by inappropriate storage conditions that promote insect infestation. Synthetic pesticides are associated with serious adverse effects on humans and the environment. Thus, finding alternative “green” insecticides is a very pressing need. Calotropis procera (Aiton) Dryand (Apocynaceae) growing in Saudi Arabia was selected for this purpose. LC-MS/MS analysis was applied to investigate the metabolic composition of different C. procera extracts. Particularly, C. procera latex and leaves showed a high presence of cardenolides including calactin, uscharidin, 15β-hydroxy-calactin, 16β-hydroxy-calactin, and 12β-hydroxy-calactin. The ovicidal activity of the extracts from different plant organs (flowers, leaves, branches, roots), and of the latex, against Cadra cautella (Walker) (Lepidoptera, Pyralidae) was assessed. Extracts of C. procera roots displayed the most potent activity with 50% of C. cautella eggs not hatching at 10.000 ppm (1%).

Comparison of In Vitro Efficacy of Six Disinfectants on the Hatching of Larval Eggs of Toxocara canis

Background: The environmental contamination with Toxocara canis eggs increases the risk of dissemination and transmission of the parasite in dogs and paratenic hosts such as humans. We aimed to evaluate different disinfectants to compare their effect on T. canis eggs. Methods: For its realization, 850 embryonated eggs were obtained, which were suspended in a solution of 5% formaldehyde and distilled water in Eppendorf tubes. In the tubes containing the 850 embryonated eggs, researchers was added 0.5 mL of each solution (enzymatic solution, sodium hypochlorite, iodopovidone, quaternary of ammonium, benzalkonium chloride, and super oxidation solution). After mixing, an aliquot was taken, observed under the microscope, and the number of broken eggs counted at different times to find the most effective ovicidal moment. Results: The enzymatic disinfectant present a significant difference (P = 0.05) with 276.06 broken eggs followed by ammonium with 105.20 broken eggs. After 10 min, the ammonium solution was the one that showed a significant difference of 50.50 hatched eggs, followed by the enzymatic 26.80 and hypochlorite 25.00 treatments. After 20 min, the enzymatic solution treatment showed a significant difference with the other solutions showing an increase of 98.80 broken eggs. In the 30 and 40-min times, only the enzymatic treatment showed a significant difference of 334.10 and 381.70 of broken eggs respectively. Conclusion: The enzymatic solution has the greatest ovicidal effect against the eggs of T. canis to present a greater number of broken eggs in a given time between 20 and 40 minutes.

BASES FOR METHODOLOGICAL APPROACHES TO FORECASTING OF PATHOGENESIS PROCESSES IN THE TREMATODE BODY AFTER ANIMAL CHEMOTHERAPY

The prospect of effective deworming is associated with the study of the mechanism of action of anthelmintics on helminths, its organs and tissues. The long-term use of methodological approaches using histological, histochemical and morphometric methods for studying organs and tissues of different types of trematodes (fascioli, euritrem, opisthorchia, dicrocelia, paramphistoma, etc.) after the anthelmintics action is effective, since it allows you to establish the mechanism and drug action on helminths. Using these methods, morphophysiological shifts were identified in the organs and tissues of trematodes, the degree of which corresponded proportionally to the dose of the applied anthelmintic on the one hand, and was determined by the chemical structure of the drug itself and the duration of its exposure, on the other. The importance of the trematodocidal effect of anthelmintics is associated with the ovicidal effect and the blocking of the trematode reproduction in which the process of egg formation is disturbed. The egg pathology covers not only the destruction of the structure of their contents at the cellular level, but is also associated with the destruction of their genome. The cessation of the release of invasive material or the release of degenerative eggs into the environment after deworming contributes to the ecologic sterilization of the environment, and its sanitation.