Egg Hatch Research Articles

The SA-WRKY70-PR-Callose Axis Mediates Plant Defense Against Whitefly Eggs

The molecular mechanisms of plant responses to phytophagous insect eggs are poorly understood, despite their importance in insect–plant interactions. This study investigates the plant defense mechanisms triggered by the eggs of whitefly Bemisia tabaci, a globally significant agricultural pest. A transcriptome comparison of tobacco plants with and without eggs revealed that whitefly eggs may activate the response of defense-related genes, including those involved in the salicylic acid (SA) signaling pathway. SA levels are induced by eggs, resulting in a reduction in egg hatching, which suggests that SA plays a key role in plant resistance to whitefly eggs. Employing Agrobacterium-mediated transient expression, virus-induced gene silencing assays, DNA–protein interaction studies, and bioassays, we elucidate the regulatory mechanisms involved. Pathogenesis-related proteins NtPR1-L1 and NtPR5-L2, downstream of the SA pathway, also affect whitefly egg hatching. The SA-regulated transcription factor NtWRKY70a directly binds to the NtPR1-L1 promoter, enhancing its expression. Moreover, NtPR1-L1 promotes callose deposition, which may impede the eggs’ access to water and nutrients. This study establishes the SA-WRKY70-PR-callose axis as a key mechanism linking plant responses and defenses against whitefly eggs, providing new insights into the molecular interactions between plants and insect eggs.

Pleiotropic effects of Ebony on pigmentation and development in the Asian multi-coloured ladybird beetle, Harmonia axyridis (Coleoptera: Coccinellidae).

Melanin plays a pivotal role in insect body pigmentation, significantly contributing to their adaptation to diverse biotic and abiotic environmental challenges. Several genes involved in insect melanin synthesis showed pleiotropic effects on insect development and reproduction. Among these, the N-β-alanyl dopamine synthetase gene (Ebony) is integral to the pigmentation process. However, the full spectrum of its pleiotropic impacts is not yet thoroughly understood. In this study, we identified and characterised the HaEbony gene in the Asian multi-coloured ladybird beetle (Harmonia axyridis) and found that HaEbony gene is a conserved gene within the Coleoptera order. We aimed to further explore the multiple roles of HaEbony in the physiology and behaviour in H. axyridis. The CRISPR/Cas9 system was applied to generate multiple HaEbony knockout allele (HaEbony+/-), showing nucleotide deletion in the G0 and G1 generations. Remarkably, the resultant HaEbony+/- mutants consistently displayed darker pigmentation than their wild-type counterparts across larval, pupal and adult stages. Furthermore, these HaEbony+/- individuals (G0) demonstrated an enhanced predatory efficiency, evidenced by a higher number of aphids consumed compared to the wild type. A significant finding was the reduced egg hatchability in both G0 and G1 generations of the HaEbony+/- group, highlighting a potential reproductive fitness cost associated with HaEbony deficiency. In conclusion, our study not only sheds light on the multifaceted roles of HaEbony in H. axyridis but also highlights the potential of employing CRISPR/Cas9-targeted modifications of the Ebony gene. Such genetic interventions could enhance the environmental adaptability and predatory efficacy of ladybirds, presenting a novel strategy in biological control application.

Gene flow stimulates recovery of reproductive fitness in a captive bred insect

Abstract Captive breeding can be a useful tool for the management of threatened species, but such programs often begin with a bottleneck which may lower reproductive fitness by increasing inbreeding and allowing deleterious alleles to increase in frequency by reducing effective population size. Dryococelus australis, the Lord Howe Island stick insect, is a critically endangered insect that has been bred at the Melbourne Zoo in Melbourne, Australia, since shortly after the species was rediscovered in 2001. We analysed a long‐term dataset of phenotypic measurements from this captive breeding program to determine whether reproductive fitness has declined in captivity. We found a clear signal of decline in direct (egg hatching success) and indirect (egg and nymph size) fitness indicators over time. We compared a captive line descended from the original program founders to a new hybrid line that has recent wild ancestry. The hybrid line showed an immediate improvement in egg hatch rate, suggesting the potential for genetic rescue. Egg and nymph size did not show as dramatic a change, although this line had only existed for just over a single generation at the time of data collection. These results argue strongly for the regular sourcing of new genetic material from the wild D. australis population to counteract fitness declines in captivity. Aside from benefiting the captive population, this would also improve the prospects of establishing new wild populations in the future, using individuals sourced from captivity.

The oviposition of cotton bollworms stimulates the defense against its eggs and larvae in tomato plants.

Herbivorous insects sustain their populations by oviposition. To reduce the damage caused by herbivores, the host plant triggers a defensive response upon detection of egg deposition. However, the specific impact of the egg deposition time of the cotton bollworm Helicoverpa armigera (Lepidoptera: Noctuidae), on the tomato plant defense remains obscure. This study investigated the effects of tomato plant defenses on cotton bollworm eggs and larvae at different time intervals following egg deposition. The study revealed that tomato plant defense triggered by egg deposition did not directly affect the hatchability of the eggs. Nevertheless, it attracted Trichogramma chilonis 48 h after the egg deposition. Gas chromatography-mass spectrometry analysis of the oviposition-induced plant volatiles (OIPVs) revealed a considerable increase in the amount of α-pinene released by tomato plants 48 h after egg deposition. The olfactory results from Y-tube experiments showed that α-pinene exhibited a substantial attraction towards T. chilonis. In addition, it was found that the defense response induced by egg deposition for 24 and 48 h significantly inhibited the growth and development of the larvae. Metabolomics analysis revealed that the egg deposition of cotton bollworm altered the metabolite composition and caused significant modifications in the metabolic pathways of tomato plants. These findings provide novel insights into pest management by using egg-induced plant defenses to reduce egg hatching, and impede larval growth and development in herbivorous insects. © 2024 Society of Chemical Industry.

Purification and Identification of the Nematicidal Activity of S1 Family Trypsin-Like Serine Protease (PRA1) from Trichoderma longibrachiatum T6 Through Prokaryotic Expression and Biological Function Assays

Background/Objectives: Heterodera avenae is a highly significant plant-parasitic nematode, causing severe economic losses to global crop production each year. Trichoderma species have been found to parasitize nematodes and control them by producing enzymes that degrade eggshells. The T. longibrachiatum T6 (T6) strain has been demonstrated the parasitic and lethal effects on H. avenae cysts and eggs, associated with the increased serine protease activity and trypsin-like serine protease gene (PRA1) expression. Methods: Our present study aimed to purify the recombinant PRA1 protease through a prokaryotic expression system and identify its nematicidal activity. Results: The recombinant PRA1 protease was identified as S1 family trypsin-like serine protease, with a molecular weight of 43.16 kDa. The purified soluble protease exhibited the optimal activity at 35 °C and pH 8.0, and also demonstrating higher hydrolytic ability toward casein and skimmed milk. Meanwhile, the Ca2+ and Mg2+ enhanced its activity, while the inhibitor PMSF significantly reduced it. The contents of H. avenae eggs leaked out after treatment with the recombinant PRA1 protease, with egg hatching inhibition and relative hatching inhibition rates at 70.60% and 66.58%, respectively. In contrast, there was no sign of content dissolution, and embryos developed normally in the control group. Conclusions: Our present study revealed that the PRA1 protease of T6 strain has a lethal effect on H. avenae eggs, which providing a theoretical basis for developing biocontrol agents to control nematodes.

Inheritance and Fitness Cost of Laboratory-Selected Resistance to Cry1Ab in Hyphantria cunea Drury (Lepidoptera: Arctiidae)

Transgenic poplars have been used to control quarantine pests worldwide, such as the fall webworm (Hyphantria cunea, FW). However, the studies on the resistance mechanism of FW to Cry toxins are limited. This study obtained an FW strain with 45-fold resistance to Cry1Ab toxin by continuous screening in the laboratory. The resistance to Cry1Ab was autosomally completely recessive, and it had approximately 40-fold cross-resistance to Cry1Ac but no cross-resistance to Cry2Ab toxin. Analysis of indoor population life tables for the resistant and susceptible strains found no significant difference in the net reproduction rate (R0) between the two strains. The resistant strain had an insignificantly longer larval development duration and a comparable pupation rate, pupal weight, emergence rate, eggs laidper female, and egg hatching rate compared to the susceptible strain. This indicated that there was no fitness cost for Cry1Ab resistance. Our study helps in evaluating the risk of resistance to Cry1Ab toxin and the mechanisms of resistance to Cry1Ab toxin in FW.

Comparative fertility and hatchability of broiler grandparent stocks in Bangladesh

Checking the fertility and hatchability of broiler grandparent lines is important for improving chicken production. The Cobb-500, Ross-308, and Indian River (IR) grandparent strains were studied to determine their initial egg weight, fertility, hatchability, embryonic mortality, hatching weight, and chick survival rates. We studied a total of 2700 eggs from three different age/treatment, each consisting of three replicates with 100 eggs for each of the three genotypes. Using an automated incubator, eggs were incubated. Cobb-500 had a significantly higher mean egg weight (67.52 g) at later stage of their age compared to Ross-308 (64.22 g) and IR (65.05 g). Study also found that a higher egg weight reflects a higher day-old chick weight. The fertility rates of the Ross-308, IR, and Cobb-500 genotypes were high at 35 weeks (96.00%, 87.00%, and 93.00%) but declined after 45 weeks (64.22%, 65.05%, and 67.52%), respectively. The hatchability of Ross-308, IR, and Cobb-500 eggs at 35 weeks was 85.00%, 75.00%, and 80.00%, respectively. By 45 weeks, all genotypes had higher hatchability, with Ross-308 having the highest at 89%. But at 55 weeks, all genotype showed lowest hatchability where IR was the lowest 67%. Statistically significant variations were observed across strains at later stage. As age increased, embryonic mortality and brood mortality were higher. Compared to the other two, Ross-308 showed the lowest mortality in both embryonic and brooding cases in all three stages of their age of life. However, the IR breed consistently displayed the highest mortality rate. Same pattern showed dead in shell and culling chick’s percentages. Strain-wise, the parameters differ from each other. However, regarding overall performance, the Ross-308 strain outperformed the other two strains. Asian Australas. J. Food Saf. Secur. 2024, 8(2), 48-57

Exploring the ameliorative potential of rutin against High-Sucrose Diet-induced oxidative stress and reproductive toxicity in Drosophila melanogaster

Sucrose is a vital ingredient in numerous food items consumed regularly. However, exposure to excessive sucrose for a prolonged period can promote health issues. The reproductive system has a delicate physiology that can be targeted by various chemical stressors, including sucrose. Hence, the present in vivo study aims to unveil the impacts of the High-Sucrose Diet (HSD) on the reproductive fitness of Drosophila melanogaster. In addition, the present work has also assessed the protective potential of a bioactive compound, rutin, against it. Here, 1st instar larvae were exposed to HSD (30%) alone and in combination with rutin (100-300µM) till their adult stage. HSD disturbed sex comb morphology in adult males, while fecundity and hatchability of eggs in females. Moreover, HSD triggered gonadal ROS production, oxidative stress, and modulated endogenous antioxidants such as SOD, catalase, and glutathione in both sexes. Nuclear fragmentation and tissue injuries, along with protein and lipid oxidation, were also apparent. Elevated levels of cytosolic Iron suggested an active Fenton reaction in adults. Further, HSD modulated the activities of reproductive and metabolic mediators, including vitellogenin, malate dehydrogenase, glucose-6-phosphate dehydrogenase, and angiotensin-converting enzymes that are critical to overall reproductive fitness. Interestingly, co-treatment with rutin, mainly at 200µM, mitigated these adverse effects and restored reproductive fitness. The protective potential of rutin might be attributed to its ability to normalize redox homeostasis, reduce oxidative stress, and optimize critical enzymes involved in reproductive physiology. These findings suggest that rutin has potential therapeutic implications to counteract the reproductive hazards induced by HSD.

Green synthesis of silver nanoparticle by Hyoscyamus muticus L. extract and study of its effect on tomato infected with Meloidogyne javanica

In this study, the aqueous leaf extract of Hyoscyamus muticus L Plant leaf was prepared using three methods: maceration (MAC), microwave-assisted extraction (MAE), and ultrasonic-assisted extraction (UAE). Then, the extracts were used to synthesize silver nanoparticles (Ag NPs) in an environmentally friendly approach. The characterization of the synthesized Ag NPs was carried out by various techniques. The XRD results confirmed the successful synthesis of nano-sized Ag crystals with spherical structure. The SEM images showed the formation of Ag NPs, which were smaller than 75 nm. The UV-Vis studies showed an obvious absorption peak for Ag NPs between 400-500 nm, with a clear peak around 450 nm for all samples. The elemental analysis using the EDS technique confirmed the presence of silver in the synthesized Ag NPs. Furthermore, the effect of different concentrations of Ag NPs was investigated on hatching and second-stage juvenile (J2s) mortality of Meloidogyne javanica, under controlled conditions. The results showed that increasing concentrations of Ag NPs led to higher percentages of inhibition of egg hatching and J2s mortality. Additionally, the Ag NPs synthesized by ultrasonic-assisted extraction with lower lethal concentration were found to be more toxic to M. javanica than the extract prepared by soaking. According to the results, Ag NPs showed a stronger inhibitory effect on M. javanica egg hatching and J2s mortality compared to the total extracts and chemically synthesized Ag NPs. Also, the lowest LC50 was observed for the Ag NPs synthesized using the plant extract as: UAE > MAE (180 w) > MAE (90 w) > MAC methods. The highest inhibition of egg hatch occurred at 0.5 % v/v of Ag NPs after 72 hours and remained consistent after 120 hours.

Impact of storage period on hatching egg quality, extra-embryonic structures, embryo morphometry, hatchability, and Rosa 1 chick quality

Storage duration affects the biological value of hatching eggs. The study evaluated the composition and characteristics of hatching eggs from Rosa 1 hens, the morphometric traits of embryos and chicks, and hatching results based on storage time. A total of 1200 hatching eggs were divided into three groups: NS (control, non-stored), S4 (stored up to day 4), and S7 (stored up to day 7). Storage conditions were 17°C and approx. 60% relative humidity. Each group’s egg quality was measured for 30 eggs. Weight loss during storage was monitored. Lysozyme activity and viscosity were analyzed from fresh eggs and incubated eggs on days 7 and 14, using thin and thick albumen or amniotic fluid. Embryo morphometry was measured on days 7, 10, 14, and 18, and post-hatching results and the quality of one-day-old chicks were assessed. Eggs stored for 7 days (S7) had higher (P<0.05) weight loss compared to the NS group. The proportions of eggshell and yolk increased (P<0.05) after storage, and the yolk index decreased. Vitelline membrane strength was lower (P<0.001) in the S4 and S7 groups than in the NS group. The lowest (P<0.05) pH levels of thin, thick albumen and yolk were observed in the NS group. Lysozyme activity increased (P<0.001) in the thin albumen of eggs in the NS and S4 groups and the thick albumen from the NS group than in others. On day 7 of incubation, group S7 showed higher (P<0.05) lysozyme activity in thick albumen, with no activity in amniotic fluid. By day 14, lysozyme activity increased (P<0.001) in group S7’s thick albumen and S4 and S7 groups’ amniotic fluid. Viscosity was highest (P<0.05) in fresh eggs’ thin and thick albumen from group S7, but on day 7, thick albumen viscosity was lowest. On day 14, amniotic fluid viscosity was higher (P=0.009) in group S4 than in NS. Seven-day-old embryos in group S7 had lower (P=0.004) weight than others. Eye diameter in S7 embryos was also smaller on days 7 and 18. On day 10, NS group embryos had shorter body diagonal lengths. Storage up to 7 days adversely affected hatching efficiency. Storage affected the navel area of one-day-old chicks, with the highest neck length in male chicks from group S4 and the lowest in females from group S4. It is concluded that egg storage at 17°C and 60% relative humidity could be limited to 4 days to maintain hatchability and qualitative features.

Pathogenicity and sub-lethal activity of orally administered entomopathogenic fungi against two adult mosquito species, Aedes aegypti (Diptera: Culicidae) and Anopheles stephensi (Diptera: Culicidae)

Entomopathogenic fungi (EPF) are known for their efficacy in controlling adult mosquito populations by penetrating through their cuticle. However, the effect of oral administration of EPF on the biological parameters of Aedes aegypti and Anopheles stephensi remains largely unexplored. This study aimed to assess the effect of orally administrated EPF isolates on the survival, feeding behavior, fecundity, fertility, follicle development and host-searching behavior in response to yeast-generated CO2 of Ae. aegypti and An. stephensi. An initial screening of 50 isolates involved exposure of adult Ae. aegypti and An. stephensi by integument inoculation. Subsequently, the entomopathogenic effect of the five highly virulent isolates was confirmed through oral administration revealing Beauveria pseudobassiana 42–51 as a potent mosquito killer. B. pseudobassiana 42–51 was administered orally to evaluate sub-lethal effects. The results showed a 63 % and 43 % reduction in blood feeding of Ae. aegypti and An. stephensi, respectively. Furthermore, a decrease in egg hatching rate was observed, with a reduction of 83% for Ae. aegypti and 74% for An. stephensi on the seventh day following fungal administration, showing decreased hatchability in both species. Poor and abnormal follicle development was observed in both mosquito species. Also, the host-searching behavior was evaluated by attraction to CO2 utilizing a Y-tube olfactometer. A tendency of reduction in the attraction rate towards the odor was observed three days post-fungal administration. These findings underscore the significant impact of oral administration of B. pseudobassiana 42–51 on mosquitoes, highlighting not only its lethal effects but also sub lethal impacts on their biology. Moreover, this fungus may exhibit the potential to simultaneously control both mosquito species and serve as a biocontrol agent for the management of vector-borne diseases.

Enhanced mite control and agricultural safety with etoxazole-loaded chitin nanocrystals: Synthesis, characterization, and ecological impacts

Chitin nanocrystals (ChNCs), known for their high aspect ratio, surface charge, and mobility, are promising bio-based nanomaterials for drug delivery. However, their potential as pesticide carriers in agriculture remains underexplored. Etoxazole, a diphenyl oxalate acaricide, effectively inhibits egg hatching and the normal molting process in mites but suffers from rapid degradation and short persistence in field applications. This study introduces a novel formulation, Eto@ChNC, prepared by complexing TEMPO-oxidized ChNCs with etoxazole via a one-pot method. Eto@ChNC was evaluated for controlling Tetranychus urticae, demonstrating significantly enhanced rapid action and prolonged efficacy compared to traditional formulations. The formulation increased the synergistic effects on mite eggs and deutonymphs by 41.74 % and 67.85 %, respectively, extending effectiveness by two days. The improved performance was attributed to the enhanced wetting ability of Eto@ChNC on leaf surfaces and its superior inhibition of the epidermal chitin content in T. urticae, facilitating greater etoxazole penetration. Transcriptome sequencing revealed numerous differentially expressed genes related to chitin metabolism, elucidating the molecular mechanisms underlying the increased efficacy. Safety assessments confirmed that Eto@ChNC did not elevate toxicity to earthworms or predatory mites and promoted the growth of wheat and cowpea, underscoring its environmental safety. These findings highlight Eto@ChNC as a significant advancement in bio-based acaricide formulations, offering promising applications in mite management.

Evaluation of the performances of two artisanal incubators on the hatching of broiler breeding eggs (Yamoussoukro, Ivory Coast)

To improve poultry production in Ivory Coast, a study was carried out in the commune of Yamoussoukro with 481 eggs from two breeds of meat breeders (Rouge Flesh and Kuroilers) which were collected during their reproduction. These eggs were distributed between three incubators, two of which were artisanal (Incubator 1 and Incubator 2) and one was industrially manufactured (Incubator 3), after determining their characteristics (weight, length and diameter). Incubation parameters were measured twice a day (at 8 a.m. and 5 p.m.) and brooding parameters such as apparent hatching rate, actual hatching rate, mortality rate embryonic and shell mortality rate were estimated. The results showed a significant difference (p&lt;0.05) in the average weight of Rufous Flesh eggs (51.54±5.3 g) compared to Kuroiler eggs (50.02±5.54 g). The average temperatures recorded (37.40±0.55 °C for incubator 1; 37.58±0.49 °C for incubator 2 and 37.59±0.53 °C for incubator 3) were significantly identical (p&gt;0.05). As for the hygrometry, that of incubator 3 (59.98±6.02 %) was significantly higher (p&lt;0.05) than that of incubator 1 (54.58±1.80 %) and from incubator 2 (54.86±3.26 %). The actual hatching rate of incubator 1 (85.76±14.21 %) was significantly higher (p&lt;0.05) than that of incubator 2 (70.85±14.48 %) and identical (p&gt;0.05) to that of incubator 3 (73.95±16.45 %). Concerning the shell mortality rate, incubator 1 (1.03±2.18 %) recorded a significantly lower rate (p&lt;0.05) than that of incubator 3 (7.43±4.56 %) and significantly identical (p&gt;0.05) to that of incubator 2 (2.52±6.35 %). From this study, the artisanal incubators 1 and 2 meet the criteria for brooding and deserve to be used.

Deciphering the Biocontrol Potential of Trichoderma asperellum (Tv1) Against Fusarium-Nematode Wilt Complex in Tomato.

The study assessed Trichoderma spp. as a biocontrol agent for managing wilt-nematode complex in tomato crops, aiming to mitigate yield losses. Fusarium sp. and Meloidogyne sp. were isolated from infected plant samples and confirmed molecularly and morphologically as Fusarium oxysporum f.sp. lycopersici and Meloidogyne incognita. Four Trichoderma spp. procured from the Department of Plant Pathology, Tamil Nadu Agricultural University, India were identified molecularly as Trichoderma asperellum (Tv1), Trichoderma asperelloides (Tasd1), Trichoderma harzianum (Th1), and Trichoderma koningiopsis (Tk1) utilizing ITS and TEF1 primer pairs. Among them, Tv1 effectively inhibited the mycelial growth of pathogen isolates. Furthermore, crude metabolite of Tv1 exhibited similar effects. The mortality rate of M. incognita J2s ranged from 90.48% to 100% after 24-72 h of incubation and inhibition percentage of egg hatching reached 90.20%. The shoot length, root length, fresh weight, and dry weight of the tomato plants treated with Tv1 conidia were increased. In a pot experiment, Tv1 treatment reduced disease incidence by 64.57%, comparable to carbendazim treatment (82.32%). Tv1-treated plants had fewer root galls, egg masses, and J2s per 100 g of roots than the inoculated-untreated control plants. The root-knot index (RKI) was significantly lower in plants treated with carbafuran (1.98 ± 0.047) and Tv1 (3.06 ± 0.086) than in control (4.47 ± 0.109). The bio-control efficiency of Tv1 against M. incognita was 21.04%, and the nematodes' reproductive factor (RF) declined to 0.53 in Tv1 treatment group. Based on the findings above, it was established that Tv1 effectively controlled nematode populations and wilt disease when applied in soil.

Biocontrol Efficacy of Bacillus thuringiensis Strain 00-50-5 Against the Root-Knot Nematode Meloidogyne enterolobii in Pepper

The root-knot nematode Meloidogyne enterolobii is a major constraint to pepper production in tropical regions. In the long-term practice of root-knot nematode management, bacterial nematicides have attracted increasing attention as effective biocontrol agents. In this study, we evaluated the efficacy of Bacillus thuringiensis strain 00-50-5 (Bt 00-50-5) against M. enterolobii through in vitro, greenhouse and field trials. The cell-free supernatant of Bt 00-50-5 exhibited potent nematicidal activity against second-stage juveniles (J2s) of M. enterolobii, with mortality rates of 98.0% and 100% after 24 h and 36 h of exposure, respectively. In addition, Bt 00-50-5 showed inhibitory effects on the hatching of M. enterolobii eggs, resulting in a remarkable 96.6% reduction in the egg hatching rate after 6 days compared to the control. The pot trials showed that both pepper root galls and egg masses were reduced, and plant growth was improved after treatment with Bt 00-50-5. The field trials showed that the gall index was significantly reduced, with a 66.3% and 68.2% reduction in disease index in 2020–2021 and 2021–2022, respectively, and pepper yield was improved, with a 96.2% and 93.1% increase in yield in 2020–2021 and 2021–2022, respectively, compared to the control. These results indicate the potential use of Bt 00-50-5 as an effective biocontrol agent against M. enterolobii.

Comparative growth, production, carcass characteristics and reproduction performance of Naked Neck, Black Australorp and their crossbred chicken

This study evaluated the phenotypic and genetic parameters of indigenous Naked Neck (NN), exotic Black Australorp (BA), and their crossbred (NNBA) chickens. A total of 270 day-old chicks (30 per group) were raised under identical conditions from day 1 to 48 weeks of age. Growth performance, including body weight, daily and total gain, feed consumption, and feed conversion ratio (FCR), was highest in BA, followed by NNBA, and lowest in NN. Carcass composition also varied significantly, with BA and NNBA having higher dressing percentages (62.98% and 62.68%, respectively) compared to NN (60.60%). BA produced the heaviest eggs (54.0 g), followed by NNBA (50.9 g) and NN (47.93 g). BA also had the best egg quality, hatchability, and FCR (3.15), with NNBA showing intermediate results. NN had the poorest performance in all traits. Age at sexual maturity was earlier in NNBA (161.23 days) compared to NN and BA. The study concluded that NNBA crossbreds outperformed NN in growth, carcass traits, and egg production, indicating their potential for enhancing rural poultry farming.

Influence of storage periods of quail eggs of Radonezh breed on the results of incubation and the development of young poultry

The storage period of eggs has a negative influence on the incubation period, embryo development, egg hatchability and hatching of young animals, which ultimately reduces the economic efficiency of the poultry farm. In breeding quail farms, the collection period of hatching eggs can reach 2–3 weeks. Our studies have studied the infl uence of the storage period of hatching eggs on the duration and results of incubation, the development of young quails. These issues have been studied not enough in meat-productive quails. In Russia, similar studies have been conducted on egg-productive quails of Japanese gray breed. However, poultry with meat productivity differs in both the duration of incubation and its results due to differences in metabolism in the body. Research has been carried out at the Siberian Research Institute of Poultry Farming on the eggs of Radonezh quail breed. It has been established that storing quail eggs for more than 7 days reduced the capacity of egg hatchability by 3.3–29.0 abs.%, and the hatching of young animals by 6.2–36.5 abs.%. Extending the shelf life of quail eggs to 14–21 days increased the average incubation hour by 2.5–9.7 hours, had a statistically signifi cant infl uence during embryogenesis on the live weight of day-old quails, the use of nutrients in the yolk sac and the development of the heart, liver and muscular stomach. It is advisable to store the hatching eggs of meat-productive quails of Radonezh breed before incubation for no more than 7 days. The results of these research can be used in breeding, industrial and farm quail farms for planning the sampling time, the number of eggs laid for incubation and places for planting day-old young animals, the population of future layers, and the volumes of necessary feed.

In vitro anthelmintic activity of Chaetomorpha vieillardii ethanolic extract against adult worm motility and egg-hatching of Haemonchus contortus from sheep

This study aimed to evaluate the potential of macroalgae Chaetomorpha vieillardii as an in vitro candidate for bio-anthelmintic. Adult Worm Motility Test (AWMT) was conducted at concentration levels of 2 mg/mL, 4 mg/mL, and 6 mg/mL of C. vieillardii ethanol extract on 150 female H. contortus worms, randomly divided into 6 treatments with 5 replications, using a two way completely randomized factorial design. 0.9% sodium chloride was used as a negative control, and albendazole at 0.5 and 2 mg/mL served as positive controls. Worm motility observations were performed at 0, 0.25, 0.5, 1, 2, and subsequent time intervals until 100% of the worms were deceased. The identical treatment was applied to the egg hatching inhibiting test (EHIT) using a completely randomized design in a one-way pattern by observing the number of eggs at 0 and 24 hours. The results showed that the concentration level of C. vieillardii ethanol extract and the observation time significantly influenced (P&lt;0.01) the motility of H. contortus, and there was an interaction between them (P&lt;0.01). All three levels were able to decrease the motility of H. contortus, but they were unable to match albendazole. Despite of this result, the three levels were equally effective (P&lt;0.01) as albendazole in terms of inhibiting the egg-hatching of H. contortus. The 2 mg/mL level was sufficient to inhibit the motility and egg-hatching of H. contortus. These findings indicated that the ethanol extract of C. vieillardii has the potential to be developed as a bio-anthelmintic for ruminants.

Beauveria bassiana associated with a novel biomimetic hydrogel to control Aedes albopictus through lure and kill ovitraps.

Within the framework of sustainable and effective control methods for Aedes albopictus, two different conidial suspensions, BbCS-1 and BbCS-2 (respectively without and with nutrients), were used as solvents for the biopolymers water-soluble 2-hydroxyethylcellulose (HEC) and sodium alginate (SA). In this way, two different classes of hydrogels were prepared for each polymer (previously shown to attract tiger mosquito oviposition) to produce HEC-based and SA-based Bb/Gel systems with and without nutrients. The aim was to achieve a long-lasting and cost-effective lure-and-kill oviposition substrate useful for lethal ovitraps. Beauveria bassiana (Bb) survival and growth in the different Bb/Gel systems were monitored for 24 days. Following the growth assay, 24-day-old Bb/Gel systems were tested against Ae. albopictus eggs through a hatching test to evaluate their lethal effect. Gel systems enhance Bb's longevity (up to 24 days) more effectively than standard liquid conidial suspensions, proving that tested HEC- and SA-based hydrogels are not toxic for Bb (biocompatibility) and create a microenvironment suitable to sustain prolonged fungal growth. In particular, the results indicate that gel system based on hydroxyethylcellulose is a suitable delivery substrate for supporting the activity of Bb and is simultaneously effective against Ae. albopictus eggs through a combined mechanism of mechanical effect and fungal action (CM > 90%). The efficacy of Bb gel systems was assessed according to its properties in favouring the growth and vitality of Bb as well as in reducing the Ae. albopictus hatching eggs rate. Further studies, in semi-field and field conditions, will be useful to evaluate the efficacy of Bb/Gel systems on adults in terms of attraction, oviposition, mortality, and potential autodissemination to propose a new tool in precision pest management. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

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.