Egg Hatch Research Articles

The Field Assessment of Quiescent Egg Populations of Aedes aegypti and Aedes albopictus during the Dry Season in Tapachula, Chiapas, Mexico, and Its Potential Impact on Vector Control Strategies.

Although integrated management and control programs implement intense control measures for adult, pupal, larval, and breeding sites during outbreaks, there is a lack of studies to understand the role of the vector egg stage in disease dynamics. This study aimed to assess the dry season quiescent Aedes aegypti and Aedes albopictus egg populations in houses and backyards in Tapachula, southern Mexico. Two hundred and fifty ovitraps were placed in 125 homes in the Las Americas neighborhood. A total of 7290 eggs were collected from 211 (84.4%) ovitraps. Only 5667 (77.7%) hatched under insectary water immersion and food supply conditions, with 4031 (71.1%) identified as Ae. aegypti, and 1636 (28.8%) as Ae. albopictus, respectively. The remaining 1623 (22.3%) did not hatch due to Delayed Hatching and/or quiescence tropical stage. Eighty-three larval containers were sampled with desiccated eggs during the dry season; most of them were described as trash waste because larvicides are only used for larger containers of 5-10 L. Evolutionary characteristics for the two species including partial egg hatching, ambient-regulated quiescence, the ability of the embryo to survive for a more extended period intra-seasonally, the egg sticking to inner container walls, demands urgent operational research to achieve successful egg-proof larval container methods.

Future semiochemical control of codling moth, Cydia pomonella

Codling moth (CM), Cydia pomonella, is a significant pest of apple (Malus domestica) and other orchard crops worldwide, posing challenges due to the decrease in registered insecticides, rising resistance, and a changing climate. The pest exhibits a strong resistance capacity to both synthetic and natural insecticides, while shifting seasonal temperatures disrupt the reliability of phenology-temperature models for predicting targeted control strategies. Alternative control strategies are necessary to future-proof control of this pest. Current control methods primarily rely on chemical insecticide sprays or granulosis virus applications during egg hatching. This review focuses explicitly on semiochemical-based manipulation of CM adults and larvae for control in orchards. Topics covered include the role of semiochemicals in integrated pest management, area-wide control, mating disruption, female attractants, larval kairomones, and incorporation into monitoring and control strategies. The potential of CM repellents in a push–pull strategy is also discussed. Primary sources for identifying relevant literature included GoogleScholar and ResearchGate, with a focus on papers published since 2013 but also include relevant papers from 2003. Nine review papers and 119 papers were reviewed. The review emphasizes that effective control necessitates an area-wide approach targeting all life stages (eggs, larvae, pupae, and adults). Comprehensive monitoring is crucial for identifying CM “hot-spots” and enhancing targeted interventions. Growers must consider landscape context when designing control programs. Lastly, recommendations are provided for future research and CM management strategies. There are opportunities to explore and exploit female kairomone attractants and repellents in control strategies and modify monitoring traps to be more attractive and autonomous.

The impact of lethal and sub-lethal exposure of emamectin benzoate on populations of Spodoptera litura (Lepidoptera: Noctuidae) under laboratory conditions

Emamectin benzoate is an avermectin bio-insecticide commonly used for managing several insect pests including Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), a major polyphagous pest of many cultivated crops. The current study was conducted to evaluate the effects of emamectin benzoate on the fitness of S. litura populations exhibiting differential susceptibility to insecticide. The selection process and all the bioassays were carried out using 6-day-old 2nd instar larvae of S. litura. A field-collected population of S. litura was divided into two groups: one selected with emamectin benzoate for eight generations (EB-Sel) and the other kept unexposed (Unsel-Lab) to insecticide in the laboratory. An increase in resistance ratio from 1.71-fold in the F1 generation to 22.54-fold in the F8 generation of the EB-Sel population was observed compared to the Unsel-Lab (F8) population. The EB-Sel and Unsel-Lab populations were treated with their respective lethal and sub-lethal concentrations which resulted in an extended development period, decreased larval survival, and adult emergence along with increased morphological abnormalities in adults. Significant reductions were observed in both male and female longevity, fecundity, egg hatching, net reproductive rate (R0), intrinsic rate of increase (rm), and finite rate of increase (λ) in EB-Sel and Unsel-Lab populations. Higher concentrations of the insecticide also reduced the relative fitness (Rf) of S. litura larvae, with maximum effect at LC50 of the EB-Sel population where the Rf value was 0.32 compared to the Unsel-Lab population. Both populations have been affected by emamectin benzoate exposure, however, the impact was more pronounced in the EB-Sel population indicating fitness costs. Our results suggested the fitness cost linked to emamectin benzoate resistance in S. litura which might favor managing insecticide resistance by reducing the frequency of resistant alleles by removing selection pressure. Consequently, our research provides significant insights to devise better pest management strategies for S. litura.

Evaluation of Compost and Manure Amendments for Suppressing Heterodera glycines.

Soybean cyst nematode (SCN) is a major pest of soybean crops, causing significant yield losses and economic impact. Current management strategies primarily rely on resistant varieties, cover crops, and seed treatments. In addition, there is a growing interest in developing sustainable, ecologically based approaches to integrate SCN risk reduction into soybean production systems. This study aimed to evaluate the efficacy of various compost and manure amendments in suppressing SCN populations and promoting soybean productivity. An in vitro egg hatching assay was conducted to screen the inhibitory effects of different compost and manure extracts on SCN egg hatching. Results indicated that poultry manure, Layer Ash Blend, and swine manure extracts significantly inhibited SCN hatching compared with other treatments across multiple time points. Greenhouse trials further validated the effectiveness of Layer Manure, poultry manure, High Carbon Dairy Doo, and Seed Starter 101 in suppressing SCN cysts, eggs, and juveniles. A field microplot trial confirmed the potential of Layer Ash Blend and poultry manure in SCN management, with significant reductions in SCN populations and increased soybean yields. The study also investigated the impact of these amendments on promoting the population of bacterivorous and frugivorous nematodes, contributing to a biological diverse soil ecosystem. Overall, the results indicate that amending SCN-infested soil with specific compost or manure formulations can effectively suppress nematode populations while improving soybean productivity. These findings contribute to the development of sustainable strategies for SCN management in soybean production systems.

Exposure to Cyantraniliprole Adversely Impacts Fitness of Harmonia axyridis: Acute Toxicity and Sublethal Effects on Development, Fecundity and Antioxidant Responses.

Extensive utilization of pesticides and their persistent residues inadvertently pose threats to the effectiveness and fitness of biocontrol agents in agroecosystems. However, these ecological consequences are generally disregarded when executing integrated pest management strategies (IPM). Cyantraniliprole (CNAP) serves as a wide-spectrum diamide insecticide and its sublethal effects have been well characterized on multiple insect pests, whereas its impacts on beneficial natural enemies remain unfathomed. Herein we exposed Harmonia axyridis, a predacious generalist, to lethal and sublethal concentrations of CNAP via dipping treatment (egg stage) and topical applications (1st-instar stage + adult stage). The acute toxicity tests revealed that LC50 of CNAP were 90.11, 86.11 and 240.50 mg/L against embryos, 1st instar nymphs and female adults, respectively, with safety factors ranging from 1.14 to 5.34, suggesting its medium toxicity for H. axyridis and larval stage was the most susceptible. The embryonic, larval and pupal durations of coccinellids ecdysed from CNAP-treated eggs and 1st instars were all elongated under sublethal concentrations, of which LC30 triggered more pronounced and significant retardations relative to control. Besides, exposed coccinellids displayed substantially diminished pupal mass and pupation rate, most notably for insects molted from the 1st-instar stage upon CNAP sublethal treatments. With respect to reproductive performance, LC10 and LC30 of CNAP all significantly suppressed female fecundity, as evidenced by reduced vitellin content, a prolonged pre-oviposition period (POP), mitigated laid eggs and the egg hatching rate. Specifically, there existed positive correlations between vitellin level (Vn) and number of eggs deposited by per female, indicative of CNAP affecting fecundity by regulation of Vn. In addition, the antioxidant system was also profoundly disrupted by CNAP, with compromised POD activity at different concentrations over time and induced hormesis of SOD/CAT activities post LC10 exposure. Activities of SOD and TAC were enhanced to exert protective functions during the first 48 h, while defense collapsed at 72 h following LC30 treatments that depleted all enzymatic activities. We speculated that fitness trade-offs may occur between reproductive capacity and antioxidant defenses to sustain physiological homeostasis in response to CNAP stress. Collectively, this study evaluated the ecological risk of CNAP and unmasked its adverse implications for overall fitness of H. axyridis, which highlighted rational application of agrochemicals to conserve biocontrol agents when implementing IPM strategies for sustainable pest control.

How a constructed wetland within a natural park enhances plankton communities after more than 10 years of operation: Changes over space and time

Constructed wetlands are increasingly used as a solution to treat polluted water in natural environments. Located in the Albufera de València Natural Park, a constructed wetland was built in 2009 as a pilot project to act as an intermediary between low-quality waters and the largest protected coastal lagoon in the Iberian Peninsula. With a unique dataset spanning more than a decade (2009–2023), this study assessed changes in plankton communities both spatially (comparing six sampling sites) and temporally (comparing four periods of years). The results show how the constructed wetland, after nearly 15 years of operation, has not only maintained but also improved its capacity to enhance the biological quality of the water which is released into the protected lagoon, thus fulfilling one of the main aims of its construction. During the last period (2020–2023) of the time series, the constructed wetland outlets had significantly higher zooplankton biomass, particularly filter-feeding cladocerans, compared to the inlets. This clear improvement in the plankton community was due to management interventions (e.g., drying sectors of the constructed wetland during the summers since 2019) and the rise in temperature. These circumstances promoted earlier hatching of cladoceran diapause eggs from the sediments compared to previous years, maintaining their presence throughout all seasons. Consequently, the outlets of the constructed wetland had significantly lower phytoplankton abundance and sestonic chlorophyll-a concentrations than in the past, nearly oligotrophic states, and a reduced biovolume of potentially toxic cyanobacteria in the released waters.

Discovery of novel nematicidal active ingredient 2,4,7-trichloroquinazoline as a potential succinic dehydrogenase inhibitor

Plant-parasitic nematodes seriously affect the growth and yield of crops, causing huge economic losses to world agriculture. One of the effective ways to manage nematode diseases is the use of nematicides. Compound B1 was found to have good nematicidal activity in the biological test. Therefore, some compounds with similar structures to B1 were tested for better nematicidal activities. Among them, the LC50 of compound C3 against pine wood nematode (Bursaphelenchus xylophilus), rice stem nematode (Aphelenchoides besseyi), and sweet potato stem nematode (Ditylenchus destructor) were 4.6, 22.4, and 16.9 mg/L, respectively, which are markedly better than tioxazafen (103.9, 56.2, and 61.0 mg/L). Compound C3 was capable of not only significantly promoting oxidative stress in Bursaphelenchus xylophilus (B. xylophilus), but also curtailing population growth by influencing the frequency of head swing frequency, feeding behaviors, reproductive capabilities, and egg hatching rates. Furthermore, Compound C3 has demonstrated a favorable binding affinity to the succinic dehydrogenase (SDH) protein and has significantly dampened the activity of the SDH in B. xylophilus. Therefore, compound C3 can be used as a potential lead compound to discover new nematicides.

Bifenthrin at Sublethal Concentrations Suppresses Mating and Laying of Female Conogethes punctiferalis by Regulating Sex Pheromone Biosynthesis and JH Signals.

Conogethes punctiferalis, a polyphagous pest in Asia, infests various crops, causing severe economic losses. Its larvae feed inside plants, making management challenging, with conventional insecticides. This study examines sublethal bifenthrin effects on the reproductive capabilities of adult females. Findings show sublethal bifenthrin concentrations (LC1, LC10, LC20, and LC30) significantly reduce sex pheromone production and mating success in a dose-dependent manner. Furthermore, these sublethal exposures influence the expression of pheromone biosynthesis activating neuropeptide and key juvenile hormone signaling genes, including methoprene-tolerant and Krüppel-homologue 1. Enzyme activity assays and metabolite measurements indicated that sublethal bifenthrin exposure decreases trehalose and pyruvic acid levels, suppressing the enzyme activities required for sex pheromone biosynthesis. Additionally, bifenthrin exposure delays ovarian development, reduces ovary size, and decreases egg production and hatchability. These results suggest bifenthrin's potential in attract-and-kill strategies by disrupting essential pathways for pest control, offering insights for improved insecticide use and innovative pest management for C. punctiferalis.

Pesticide and antimicrobial evaluation of three labdane-type diterpenes, and one flavonoid glycoside, isolated from rhizomes of Hedychium coronarium J. Koenig

Three labdane-type diterpenes, namely coronalactoside I, hedychilactone A, and (E)-labda-8(17),12-dien-15(16)-olide, along with the flavonoid glycoside Isolinariin A, were isolated from Heydichium coronarium. Structural elucidation employed spectroscopic techniques (IR, MS, NMR, and DEPT) and comparison with literature data. Pesticidal and antimicrobial activities were assessed. Isolinariin A exhibited potent nematicidal activity (71.33% mortality) against Meloidogyne incognita, while Coronalactoside I demonstrated strong inhibition of nematode egg hatchability (26.00% at 1 µg/mL). In insecticidal activity against Spodoptera litura, (E)-labda-8(17),12-dien-15(16)-olide displayed significant mortality (93.66% at 100 µg/mL). Molecular docking studies indicated favourable interactions with target proteins, suggesting potential in pest management. These findings propose the application of these compounds to mitigate the ecological impact of synthetic pesticides.

Yellow mealworm: effects of adults breeding density on adults and larvae performances from an industrial perspective

A key aspect to optimise the Tenebrio molitor (TM) farm productivity is to find an optimal breeding density for adults. To this purpose, this study investigated, from an industrial perspective, the impact of 4 breeding densities (D1, D2, D3 and D4, equal to 0.8, 1.1, 1.3 and 1.6 adults/cm2, respectively) on mortality and reproductive performances of TM adults and larvae. Two weeks after pupae emergence, TM adults were randomly assigned to the four groups and housed in 48 breeding crates (60 x 40 x 14.5 cm; 12 crates/group). The trial consisted in 4 consecutive weeks of adults breeding (each week represented one oviposition), and 8 weeks of larvae growth. From each week of oviposition, a batch of larvae was obtained for a total of 4 batches of larvae (48 crates/batch). Larvae of each batch were grown until 8 weeks of age, corresponding to the period required to reach the selling size. Larvae were kept in the original crates until the 5th weeks of age, after which they were divided into additional crates to ensure a density of 4.2 larvae/cm2 and a final weight of 1500 g of larvae/crate (0.6 g of larvae/cm2). For each oviposition week, TM adult’s mortality, eggs hatchability, BW, feed intake, chemical composition and fatty acids (FAs) profile were evaluated, while ovary weight was measured at weeks 1 and 4. The number of larvae was monitored at week 5 of age while their chemical composition at week 5 and 8. Larvae feed intake and BW were monitored over the 8-weeks growth period. Individual feed intake and BW of adults increased with increasing breeding density (P<0.0001 and P<0.05, respectively). With increasing adults breeding density, the number of larvae per crate increased (P<0.001) while the grams of larvae/gram of adult decreased (R2=0.8856). Larvae from groups D2, D3 and D4 showed higher feed intake per crate and higher individual and total final BW than D1 (P<0.001). However, the feed conversion ratio (FCR) worsened with increasing breeding density (P<0.001). D4 larvae had higher percentages of protein (P<0.001), lipids (P<0.05) and cholesterol (P<0.001) compared to larvae from other groups. Concluding, a breeding density of 0.8 adults/cm2 maximised both grams of larvae produced/grams of adults and larvae FCR. However, breeding densities above 0.8 adults/cm2, resulted in a higher number of produced larvae per crate with a greater final mass weight making a density of 1.6 adults/cm2 the preferable choice from and industrial perspective.

The Impact of In Ovo Injection of Organic Manganese on Broiler Breeder Hen Egg Hatchability and Progeny Broilers Productivity

The Impact of In Ovo Injection of Organic Manganese on Broiler Breeder Hen Egg Hatchability and Progeny Broilers Productivity

Acaricidal, larvacidal, and repellent activity of Linalool loaded zinc oxide nanoparticles against Hyalomma anatolicum.

Current strategies for tick control have led to the development of resistance and environmental contamination. Consequently, there is an urgent need for research into new and effective acaricides for tick control. The aim of this study was to fabricate and characterize Linalool loaded zinc oxide nanoparticles (Lin@ZNP), and to assess the acaricidal, larvacidal, and repellent activities of Lin@ ZNP against Hyalomma anatolicum, a prevalent tick species infesting cattle in Saudi Arabia. Lin@ ZNP was synthesized using an ethanolic solution of polyvinyl alcohol. The adult immersion, the larval packet, and the assessment of vertical movement behavior of tick larvae assays were utilized to examine the acaricidal, larvicidal, and repellent activities of Lin@ZNP against H. anatolicum, respectively. Furthermore, the impact of Lin@ZNP on acetylcholinesterase and oxidant/antioxidant enzyme activities was investigated. Exposure of adult H. anatolicum to different concentrations of Lin@ZNP resulted in noticeable (p<0.001) reductions in the viability rate of adults and the mean number, weight, and hatchability of eggs, compared to the control group. Lin@ZNP demonstrated significant repellent effects on H. anatolicum larvae after 60, 120, and 180 minutes of exposure. Lin@ZNP, particularly at all concentrations, markedly suppressed the acetylcholinesterase activity of the larval stage of H. anatolicum (P<0.001); but increase in malondialdehyde (MDA) levels (P<0.001) and a decrease in glutathione-S-transferase (GST) levels in H. anatolicum larvae (P<0.001). Lin@ZNP exhibited considerable acaricidal, larvicidal, and repellent effects against H. dromedarii adults and larvae in a manner dependent on the dosage. Additionally, Lin@ZNP notably reduced AChE levels and antioxidant activity, while inducing oxidative stress in H. anatolicum larvae. Nevertheless, further research is necessary to elucidate the precise mechanisms and practical efficacy of Lin@ZNP.

Effects of Microbial Biostimulants on Maize and Its Pest, the Western Corn Rootworm, Diabrotica virgifera virgifera

The western corn rootworm, Diabrotica virgifera virgifera, (Coleoptera: Chrysomelidae) is a serious pest of maize in the USA and Europe. Microbial plant biostimulants such as bacteria, fungi, and algae are designed to stimulate plant nutrition and growth, with some hypothesized to also possess insecticidal properties. We tested 10 biostimulants (four bacteria, five fungi, and one alga) under laboratory and greenhouse conditions. Most biostimulants did not affect the eggs, larvae, or adults of D.v. virgifera. However, in the laboratory, 10% of biostimulants improved egg hatching, and 40% killed some larvae, including the fungi Beauveria bassiana, Rhizophagus irregularis, and Trichoderma asperellum, and the bacterium Ensifer meliloti. Under potted-plant conditions in the greenhouse, these insecticidal effects were not detectable. However, several biostimulants slightly increased height and shoot length of uninfested maize plants, but reduced volume and length of their roots as well as above-ground biomass. Interestingly, 30% of the biostimulants enhanced the plant’s defence against larvae, for example, Bacillus amyloliquefaciens, B. subtilis, and E. meliloti. These may warrant further research into their modes of action as well as field trials to better understand and optimize their potential use in sustainable and integrated pest management.

Evaluation of Egg Production, Fertility, Hatchability, Embryonic Mortality and Chick Quality of Different Chickens

The present study was evaluated the egg production performance, fertility, hatchability, embryonic mortality and chick quality from Cosmopolitan (C), Improved Horro (H), ♂Improved Horro*Cosmopolitan ♀ (HC), ♂ Cosmopolitan*Improved Horro ♀ (CH), Indigenous (L), and Koekoek (KK) genotypes. A Completely randomized design was used in the study. A total of 1800 eggs and 300 eggs of each genotype were used for the hatchability and fertility trials. A total of 360 chicks and 60 chicks of each genotype were used for chick quality study. A total of 720 genotypes (5female: 1 male) and 120 from each genotype were used for egg production. Age at first egg and age at peak varied across genotypes. KK had the highest egg production followed by CH, H, CH and C but L had the lowest egg production. KK had the highest weight and feed intake followed by HC, HC, and C, whereas had the lowest followed by H. Feed conversion ratio varied among genotypes. H had the highest egg fertility followed by CH. Conversely, C, HC, L and KK chicken genotypes were comparable and had the least egg fertility. H and CH showed the highest hatchability from set egg, whereas L showed the lowest hatchability from set egg followed by the intermediate KK, HC and C. CH indicated the highest hatchability from fertile egg set, while L confirmed that the lowest hatchability from fertile egg set followed by the intermediate KK, HC and C. The overall embryonic mortality of L was the highest, but CH had significantly lowest overall embryonic mortality followed by KK, HC and C. Chicks hatched from KK had the highest chick weight and chick length, but chicks hatched from L had the least chick weight and chick length. Eggs of L had the highest percentage egg weight yield followed by KK, whereas the CH, C, HC and H had intermediate yield percent during incubation. Conclusively: The genotype differences of hens substantially influenced egg production performance, fertility, embryonic mortality, hatchability and chick quality.

Harnessing the Phytochemistry Through Pesticidal Potential of Diverse Elsholtzia Species: A Path to Sustainable Agriculture.

This study investigates the phytochemical profiles and pesticidal activities of various Elsholtzia species, including E. ciliata, E. flava, E. fruticosa, and E. eriostachya, to discover their bioactive potential for sustainable pest management. Through comparative phytochemical analysis using GC-MS technique, key compounds in the essential oils were identified. The major components were thymoquinone (44.97%) in E. ciliata, shisofuran (28.66%) in E. flava, perillene (50.88%) in E. fruticosa, and pinocarvone (42.41%) in E. eriostachya. Despite variability in chemical composition, all species primarily contained oxygenated monoterpenes. The bioactivity of the oils was evaluated for their nematicidal and herbicidal bioassays. E. ciliata showed the highest egg hatching inhibition and juvenile mortality of M. incognita, while E. flava exhibited the lowest activity. For herbicidal activity, E. eriostachya achieved 96.70% seed germination inhibition, 100% root growth inhibition, and 95.56% shoot growth inhibition. E. flava showed the lowest inhibition in germination, root length, and shoot length at 66.70%, 81.56%, and 85.28%, respectively. The findings revealed significant variations in phytochemical composition and pesticidal efficacy, emphasizing the importance of species selection for pest management. This research highlights the bioactive potential of Elsholtzia species in sustainable pest management strategies.

Internet of Things Based Water Quality Control System

Fish incubation, which involves the hatching of fish eggs, represents the process of embryogenesis until the embryo emerges from its protective shell. This intricate developmental journey is influenced by a combination of internal and external factors. External factors can be influenced by water quality that is not suitable for hatching fish eggs. Water quality, which includes temperature, dissolved oxygen, light intensity, salinity, and pH, is an important and limiting factor for living creatures that live in water, including chemical, biological, and physical factors. Poor water quality can prevent fish eggs from hatching and even cause death. The primary objective here is the creation of an Internet of Things (IoT)-based system designed for controlling water quality during fish incubation. This system is intended to aid fish farmers in effectively control the environmental conditions within their incubation ponds. The method used in designing IoT device is research and development, and it uses the Arduino Mega microcontroller as the main device to run pH sensors, turbidity sensors, oxygen sensors, temperature sensors, and relay modules. Water Quality Control System The fish incubation was successful. The average time needed to change the water temperature from 28.5 to 29 degrees Celsius is 4 minutes and 7 seconds; change the dissolved oxygen level from 11 to 11.5 is 3 minutes and 33 seconds; change the pH value of the water from 6.9 to 7.1; and maintain turbidity below 5 with an average time of 5 minutes and 58 seconds. Controlling water quality can speed up the fish egg incubation process for 8 hours.

Toxicity of Common Acaricides, Disinfectants, and Natural Compounds against Eggs of Rhipicephalus annulatus.

Ticks pose a significant threat due to their ability to lay thousands of eggs, which can persist in the environment for extended periods. While the impact of various compounds on adult and larval ticks has been studied, research on their efficacy against tick eggs is limited. This study evaluated the ovicidal activity of commercial acaricides, disinfectants, and natural products against Rhipicephalus annulatus eggs using the egg hatch assay (EHA). Deltamethrin and cypermethrin caused a non-significant inhibition of hatching (IH%), even at concentrations higher than the recommended levels. By contrast, the acaricides chlorpyrifos, phoxim, and amitraz significantly inhibited hatching at all tested concentrations. Ivermectin also demonstrated significant IH% at various concentrations but did not fully inhibit the hatching process. Among the disinfectants tested, Virkon-S®, TH4, and Chlorox showed insignificant effects, whereas formalin achieved an IH% of only 34.1% at a high concentration of 200 mg/mL. Natural products, carvacrol and thymol, exhibited significant ovicidal activity, with a significant IH%. In a semi-field application, phoxim (0.5 mg/mL) and deltamethrin (0.05 mg/mL) were sprayed on tick eggs on pasture soil from a farm. The results indicated that phoxim-treated eggs had a 40% IH%, while deltamethrin-treated eggs showed only an 8.79% IH%. In conclusion, the acaricides amitraz, phoxim, and chlorpyrifos, as well as the natural products carvacrol and thymol, caused significant toxicity to R. annulatus eggs.

In vitro anthelmintic activity of hydroethanolic extract of Artemisia herba aba and Juniperus phoenicea on abomasal Teladorsagia circumcincta of sheep.

The present study aimed to evaluate the in vitro anthelmintic activity of Juniperus phoenicea and Artemisia herba-alba against abomasal nematodes collected from naturally infected sheep. The anthelmintic activities of the extracts were assessed using egg hatch inhibition (EHIA) and adult motility assays (AMA) against Teladorsagia circumcincta. The parasites were stored in phosphate-buffered saline (PBS) until the in vitro assessment began. The leaf powders of J. phoenicea and A. herba-alba were extracted using the maceration procedure. Briefly, the leaf powders were mixed with a sufficient quantity of 99% ethanol and distilled water (80%/20%). The extracts were dissolved in a 3% dimethyl sulfoxide (DMSO) solution to improve water solubility. The hydroethanolic extracts were tested at concentrations of 1.562, 3.125, 6.25, 12.5, and 25 mg/ml. Adult motile worms were individually subjected to each treatment at laboratory temperature. The PBS and albendazole (25 mg/ml) were prepared and used as negative and positive controls, respectively. The test was repeated five times for each concentration. The results showed that both plant extracts exhibited anthelmintic effects. A. herba-alba extract at 25 mg/ml inhibited the motility of all T. circumcincta adult worms within 1 hour of administration, while J. phoenicea extract caused 100% mortality of adult worms after 4 hours at the same concentration. Neither of the extracts, at 1.562 mg/ml, had any inhibitory effect on motility. At 25 mg/ml, the A. herba-alba (98.67%) and J. phoenicea (96.24%) showed high activity with an inhibitory effect on hatchability compared to the other tested concentrations. The findings of the present study showed that hydroethanolic extracts of A. herba-alba and J. phoenicea leaves had in vitro anthelmintic activity on eggs and adult T. circumcincta of sheep.

Interactions between broiler parent stock age and egg pre-incubation duration: effects on embryo development, hatchability, day-old chick weight, and yolk sac weight

Egg storage is a common practice in commercial hatcheries, but prolonged storage can negatively impact hatchability, causing a significant problem for the poultry industry. Repeated pre-incubation could mitigate the decline depending on the age of the parent stock. The study investigated the interactions between parent stock age (30, 45, and 58 weeks) and repeated pre-incubation on the hatchability and embryo development of 15-day stored eggs from Ross 308 parent stock. Three different pre-incubation durations were employed during storage: no pre-incubation and twice at the 5th and 10th days of egg storage for either 4 or 8 h. For each parent stock age, 3 600 eggs collected on the same day from the same parent stock were used for hatchability assessment. The duration of pre-incubation was determined as the eggshell temperature increased from 28 °C to a maximum of 35 °C and then cooled to 28 °C; the persistency at 35 °C was either 1 or 4 h for the total pre-incubation period. The hatchability of both set and fertile eggs and early, middle, and late embryonic mortality depended on the parent stock’s age (P < 0.001). Pre-incubation alone did not have any impact on hatchability. Conversely, a significant interaction was observed between parent stock age and pre-incubation duration on the hatchability of fertile eggs (P = 0.001). At 30 weeks of parent stock age, both durations of pre-incubation positively influenced the hatchability. At 45 weeks of parent stock age, pre-incubation length had no effect on hatchability. At 58 weeks of parent stock age, a longer pre-incubation period, 2 × 8 h, was associated with decreased hatchability. Early embryonic mortality was not influenced by pre-incubation. However, a significant interaction was observed (P = 0.003). At 30 weeks of parent stock age, both short and long lengths of pre-incubation were associated with a decrease in early embryonic mortality. However, at 45 and 58 weeks, pre-incubation did not significantly affect early embryonic mortality. Additionally, longer pre-incubation periods significantly increased middle mortality compared to untreated eggs (P = 0.035). The median of embryo development for untreated eggs was the same across all ages (stage 10). In the older parent stock (45 and 58 weeks), repeated pre-incubation increased variability in embryo development, while in the younger parent stock, repeated pre-incubation decreased variability in embryo development. In conclusion, the duration and the frequency of pre-incubation should be specified based on the age of the parent stock.

Characteristics of a Spray-Dried Porcine Blood Meal for Aedes aegypti Mosquitoes.

Research into mosquito-borne illnesses faces hurdles because feeding fresh animal blood to rear female mosquitoes presents logistical, economic, and safety challenges. In this study, a shelf-stable additive (spray-dried porcine blood; SDPB) hypothesized to supply accessible hemoglobin was evaluated within an alternative meal (AM) containing whey powder and PBS for rearing the yellow fever mosquito Aedes aegypti. LC-MS/MS proteomics, microbial assays, and particle reduction techniques confirmed and characterized the functionality of hemoglobin in SDPB, while engorgement, fecundity, egg viability, and meal stability bioassays assessed AM performance. Chemical assays supported hemoglobin as the phagostimulant in SDPB with aggregates partially solubilized in the AM that can be more accessible via particle reduction. Unpaired two-tailed t-tests indicate that the AM stimulates oogenesis (t11 = 13.6, p = 0.003) and is stable under ambient (1+ y; t12 = 0.576, p = 0.575) and aqueous (14 d; t12 = 0.515, p = 0.639) conditions without decreasing fecundity. Egg hatch rates for the ninth generation of AM-reared Ae. aegypti were 50-70+%. With further development, this meal may serve as a platform for mass rearing or studying effects of nutritional additives on mosquito fitness due to its low cost and stability. Future work may examine tuning spray drying parameters and resulting impacts on hemoglobin agglomeration and feeding.