Egg Mortality Research Articles

Lack of response to pond desiccation by eggs and tadpoles of the Yungas Red-belly Toad (Melanophryniscus rubriventris) in an unpredictable environment

Anuran amphibians that breed in ephemeral ponds of unpredictable environments have mechanisms to tolerate or to avoid associated risks of egg and tadpole mortality, such as selection of oviposition sites, plasticity in larval development, and resistance of eggs to desiccation. The Yungas Red-belly Toad (Melanophryniscus rubriventris (Vellard, 1947)) breeds in temporary ponds in the Andean Yungas under unpredictable events of flooding and droughts of reproductive sites. To determine whether this species possesses any developmental mechanisms to deal with the environmental conditions, we experimentally evaluated the resistance of eggs subjected to different times of exposure to air and the tadpoles to different levels of pond desiccation. The species has not developed mechanisms of resistance of its eggs or phenotypic plasticity to the recurrent risks of pond desiccation, and mass mortality is a common event. In such a context, explosive breeding highly synchronized with rainfall, together with fast larval development, seems to be vitally important at these places where the duration of ponds is short and unpredictable.

Treatment of piggery waste in an ectopic microbial fermentation system and safety evaluation of generated organic fertilizer

AbstractBACKGROUNDWith the development of China’s livestock breeding industry, a large amount of waste was discharged and the local environment was seriously polluted. In this research, treatment performance of piggery waste in an ectopic fermentation system (EFS) using different padding materials and safety evaluation of generated organic fertilizer were studied in a pilot experiment.RESULTSDuring the whole fermentation process, temperature in the EFS fluctuated with addition of fresh feces and its consumption, and the pH value varied between 6.5 and 9.5. The absorption coefficient of pig breeding wastewater and feces per kilogram of padding (maize straw) at the end was 2.52 and 1.88, respectively. Bacteria played a major role in decomposing organic matter, and its number was basically maintained at 107–108 orders of magnitude. The C:N ratio in two EFS beds decreased gradually and was below 14:1 at the end, indicating the maturity of fermentation. Moreover, operation of the EFS with addition of rice husk/coconut shell mixture was more stable than that of EFS with maize straw. After fermentation, the heavy metal, total nutrient content, ascaris egg mortality and fecal coliform population of the generated organic fertilizer from two fermentation beds all met the limits of the Organic Fertilizer Standard of China, and the seed germination index of the product increased.CONCLUSIONSEFS employing maize straw or rice husk/coconut shell mixture as padding material can be used to treat both solid and liquid waste from pig farms. EFS technology reduced the biotoxicity of piggery waste. © 2022 Society of Chemical Industry (SCI).

Synthesis, Molecular Docking and Mosquitocidal Efficacy of Lawsone and its Derivatives Against the Dengue Vector Aedes aegypti L. (Diptera: Culicidae).

Aedes aegypti is the primary vector of dengue, a significant public health problem in many countries. Controlling of Ae. aegypti is the biggest challenge in the mosquito control programe, and there is a need for finding bioactive molecules to control Ae. aegypti in order to prevent dengue virus transmission. To assess the mosquitocidal property of lawsone and its 3-methyl-4H-chromen-3-yl-1- phenylbenzo[6,7]chromeno[2,3,c]pyrazole-dione derivatives (6a-6h) against various life stages of Ae. aegypti. Besides, to study the mode of action of the active compound by molecular docking and histopathological analysis. All derivatives were synthesized from the reaction between 2-hydroxy-1,4-naphthoquinone, chromene-3-carbaldehyde, and 1-phenyl-3-methyl-pyrazol-5-one by using one pot sequential multicomponent reaction. The mosquito life stages were subjected to diverse concentrations ranging from 1.25, 2.5, 5.0, and 10 ppm for lawsone and its derivatives. The structure of all synthesized compounds was characterized by spectroscopic analysis. Docking analysis was performed using autodock tools. Midgut sections of Ae. aegypti larvae were analyzed for histopathological effects. Among the nine compounds screened, derivative 6e showed the highest mortality on Ae. aegypti life stages. The analyzed LC<50 and LC90 results of derivative 6e were 3.01, 5.87 ppm, and 3.41, 6.28 ppm on larvae and pupae of Ae. aegypti, respectively. In the ovicidal assay, the derivative 6e recorded 47.2% egg mortality after 96-hour post-exposure to 10 ppm concentration. In molecular docking analysis, the derivative 6e confirmed strong binding interaction (-9.09 kcal/mol and -10.17 kcal/mol) with VAL 60 and HIS 62 of acetylcholinesterase 1 (AChE1) model and LYS 255, LYS 263 of kynurenine aminotransferase of Ae. aegypti, respectively. The histopathological results showed that the derivative 6e affected the columnar epithelial cells (CC) and peritrophic membrane (pM). The derivative 6e is highly effective in the life stages of Ae. aegypti mosquito and it could be used in the integrated mosquito management programe.

In vitro evaluation of the response of Dermanyssus gallinae to products in aqueous suspension.

The hematophagous mite Dermanyssus gallinae poses a serious sanitary problem in the Brazilian laying poultry industry. Its control is typically performed with acaricides, either in powder or liquid form. However, the intensive use of these products has caused populations of this species to develop tolerance and even resistance. The aim of the present study is to evaluate the response of eggs and adults of D. gallinae to products in aqueous suspension according to commercial indication and as per the recommendations of the Brazilian Ministry of Agriculture, Livestock and Supply. The study used four acaricide products (product 1: cypermethrin, chlorpyrifos, and piperonyl butoxide; product 2: alkyl-benzyl-dimethyl ammonium chloride, glutaraldehyde, deltamethrin; product 3: dichlorvos; product 4: fluralaner) tested in vitro using the contact method. Distilled water was used in the control group. The effectiveness of each of the products differed significantly between eggs and adults. Products 2, 3, and 4 caused 100% of adult mortality up to day 5 after start of treatment, product 1 97.5%. The corrected mortality (non-viability) of eggs was 21.4% (product 1) 39.4% (product 2), 47.8% (product 3), and 14.4% (product 4). Although the products evaluated were effective against adults of D. gallinae, their effectiveness against eggs was lower under the same conditions. This finding might be directly related to frequent D. gallinae reinfestations in poultry houses.

Field evaluation of Beauveria bassiana (Balsamo) Vuillemin isolates for the biocontrol of Rhipicephalus microplus (Canestrini) ticks on cattle

Formulations of the entomopathogenic fungus Beauveria bassiana (Hypocreales: Cordycipitaceae) were tested under field conditions against the bovine tick adults Rhipicephalus microplus (Acari: Ixodidae). Formulations were prepared for each fungal isolate consisting of 108 conidia.mL−1, 10% avocado oil and either of Ballista® or Break-thru® as an adjuvant sprayed on tick-infested cows. The following variables were evaluated: initial female weight, egg mass, hatching percentage, egg production index, nutritional index, reproductive efficiency and mortality. After about four days, the ticks were collected to estimate all the variables mentioned above. Mortality for treated ticks ranged from 13 to 38%. All isolate formulations significantly reduced egg mass, hatching percentage of the eggs, egg production index, nutritional index and reproductive efficiency. The current study demonstrated the potential of B. bassiana formulations for the biological control of R. microplus under environmental field conditions.

Evaluation of egg parasitoid Hadronotus pennsylvanicus as a prospective biocontrol agent of the leaffooted bug Leptoglossus zonatus

The western leaffooted bug, Leptoglossus zonatus (Dallas) (Heteroptera: Coreidae), is a key pest of almonds and pistachios in the USA. With limited monitoring strategies and no economic threshold developed, the use of broad-spectrum insecticides remains the primary control tactic for L. zonatus. In pursuit of more sustainable management options, experiments were carried out to assess the biocontrol potential of the egg parasitoid Hadronotus pennsylvanicus (Ashmead) (Hymenoptera: Scelionidae) against L. zonatus. Biological and demographical attributes of H. pennsylvanicus were evaluated under controlled laboratory conditions. Mated females lived on average 116 days. However, female longevity declined by 74% when provided with host eggs, and by 97% when deprived of a suitable diet. Females produced an average 39.70 offspring, with peak fecundity observed within the first week of their lifespan. The total progeny was on average 92.75% female. Non-reproductive host mortality accounted for > 52% of the total egg mortality observed within the first two weeks, and represented the majority of total host egg mortality thereafter. Age of host eggs did not influence parasitism rates. Under laboratory conditions, H. pennsylvanicus exhibits suitable demographic and reproductive traits as a candidate biocontrol agent of L. zonatus. Further research is needed to determine how to best manipulate and enhance H. pennsylvanicus populations to promote biocontrol of L. zonatus under field conditions.

Breeding Ecology of Aquatic Warblers Acrocephalus paludicola in their Key Habitats in SW Belarus

The breeding ecology of the Aquatic Warbler was studied on the three largest mires in Belarus in 1998–2004. Numbers of male Aquatic Warblers on these mires range from 6370 to 11500, which is more than 50% of the species world population. In years with favorable nesting conditions breeding success on the three mires varies from 36.3% to 54.1%. In years with significant water level fluctuations and irruptions of shrew populations the breeding success decreases sharply, varying from 2.9% to 27.7%. The main reason for the mortality of eggs and nestlings was predation, probably by small insectivorous mammals. The species is well adapted to the unstable nesting conditions in fen-mires; but in years with serious flooding, high water levels throughout the nesting season, disturbances to the vegetation structure after spring fires or in years with a high density of shrews, breeding success decreases significantly.

Climate Change and Livestock Production: A Literature Review

Globally, the climate is changing, and this has implications for livestock. Climate affects livestock growth rates, milk and egg production, reproductive performance, morbidity, and mortality, along with feed supply. Simultaneously, livestock is a climate change driver, generating 14.5% of total anthropogenic Greenhouse Gas (GHG) emissions. Herein, we review the literature addressing climate change and livestock, covering impacts, emissions, adaptation possibilities, and mitigation strategies. While the existing literature principally focuses on ruminants, we extended the scope to include non-ruminants. We found that livestock are affected by climate change and do enhance climate change through emissions but that there are adaptation and mitigation actions that can limit the effects of climate change. We also suggest some research directions and especially find the need for work in developing country settings. In the context of climate change, adaptation measures are pivotal to sustaining the growing demand for livestock products, but often their relevance depends on local conditions. Furthermore, mitigation is key to limiting the future extent of climate change and there are a number of possible strategies.

The Effects of Low-Level Helium–Neon (He–Ne) Laser Irradiation on Lipids and Fatty Acids, and the Activity of Energetic Metabolism Enzymes and Proteome in the Blastula Stage and Underyearlings of the Atlantic Salmon Salmo salar: A Novel Approach in Salmonid Restoration Procedures in the North

The effect of He–Ne laser irradiation on fishery parameters as well as on biochemical state, including the lipids and fatty acids, the activity of energy metabolism enzymes and the proteome in the blastula stage and in underyearlings of wild Atlantic salmon after irradiation at the cleavage stage/early blastula (considered as the stages when the cell has a high potential for differentiation) was studied. Low mortality rates of eggs were determined during embryogenesis, as well as increased weight gain and lower morality rates of underyearlings in the experimental group. This is confirmed by changes in a number of interrelated indicators of lipid metabolism: a decrease in total lipids content, including diacylglycerols, triacylglycerols, cholesterol esters, and the phospholipids content remained unchanged. The embryos in the blastula stage (experimental group) had higher aerobic capacity and an increase in pentose phosphate pathway activity. The proteome profiles of eggs in the blastula stage were 131 proteins, of which 48 were significantly identified. The major protein was found to be phosvitin. The proteomes of underyearlings were represented by 2018 proteins, of which 49 were unique for the control and 39 for the experimental group. He–Ne laser irradiation had a strong effect on the contents of histone proteins.

Seasonal and spatial variability of Atlanto-Iberian pelagic fish diet with estimates of intraguild predation

The diets of 3 of the most abundant coastal pelagic fish species in the eastern Atlantic (sardine, anchovy and Atlantic chub mackerel) were investigated, including seasonal, geographical and ontogenetic variability of the diets. We also estimated the impact of cannibalism and intraguild predation on egg mortality, and a different method to evaluate egg mortality is proposed taking the spatial overlap of predators and eggs into account. Diet overlap occurred between the 3 pelagic species, which derive most of their dietary carbon from mesozooplankton prey. However, calanoid copepods were mostly important for anchovy and sardine, whereas the diet of the Atlantic chub mackerel also included crustacean eggs, nauplii, small copepodites and larger prey such as decapods. Sardine was the main predator of fish eggs (90% of all identified eggs), followed by Atlantic chub mackerel (8%) and anchovy (2%). Cannibalism by anchovies and sardines on their eggs was low (&lt;10% of spawned eggs) for all areas and seasons. The impact of sardine predation on anchovy egg mortality was high (71% of the anchovy eggs spawned per day during the spring off northwestern Iberia) and may explain why anchovy abundance has only peaked in recent years, when sardine abundance was at its lowest level, highlighting the importance of taking an ecosystem approach to fisheries management into account. However, species-specific data of gastric evacuation rates and feeding durations are needed to obtain more accurate estimates of the impact of cannibalism and intraguild predation on egg mortality.

Optimization of CO2 Concentration on Mortality of Various Stages of Callosobruchus maculatus and Development of Controlled Atmosphere Storage Structure for Black Gram Grains

Pulse beetle ( Callosobruchus maculatus) is a common weevil that is responsible for up to 24% of stored pulse losses. Using black gram grain storage, the efficiency of carbon dioxide gas against all life stages of Callosobruchus maculatus insects was tested at various concentrations and exposure times. The trials were carried out in pilot bins with a capacity of 25 kg. At a CO2 concentration of 50%, complete mortality of the egg stage of Callosobruchus maculatus was attained after 72 h of continuous exposure. At a CO2 concentration of 60% for 48 h, 100% larva mortality was achieved. At the most tolerant stage of pupa, recorded complete mortality is at a CO2 concentration of 70% for 96 hours of the exposure period. Adult insects are especially vulnerable to the high CO2 concentration. Adult mortality was achieved at a concentration of 20% with an exposure period of 48 h. The CO2-treated black grams were then stored for three months with the optimized CO2 concentration and exposure period, while physiochemical parameters such as water retention capacity and physiological loss in weight were determined. Grain stored in the silo showing significant 100% mortality of egg was measured after 20-25 days of observation. The use of a controlled atmosphere storage bin increased the mortality of the insect C. maculatus at all developmental stages, by means of increasing CO2 concentration and exposure time. Grain stored in a controlled atmosphere silo showed minimum losses of grain (4.10%) compared to the gunny bag storage (22.56%).

Nematicidal activity of Beauveria bassiana (Bals.) vuill against root knot nematode (Meloidogyne incognita)

The pathogenic potential of Beauveria bassiana (bals.) Vuill was explored against Meloidogyne incognita (Kofoid and White) Chitwood under laboratory condition using conidial suspensions @ 2.6×106 conidia/mL (1x) with further dilutions. The mortality and inhibition of root-knot nematode eggs hatching were directly proportional to the concentration of B. bassiana culture filtrates. No egg hatching was observed at 1x (original concentration). There was a spike in eggs hatching with the increase in dilutions. The mortality of J2 and inhibition of hatching of the nematode species were also directly proportional to the concentration of culture filtrate of B. bassiana. Soil drenching with culture filtrate of B. bassiana significantly reduced the population of nematodes in the soil and gall formation in tomato plants under pot conditions.

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.

Impact of Storage Period on Fertility and Mortality in Chabro Breeds of Poultry

An investigation was conducted to study the effect of storage period on fertility and hatchability in large, medium and small sized eggs of Chabro breed. The study was conducted at poultry farm of SKN College of Agriculture, Jobner. For the present study, a total of 297 eggs were collected for this study. These eggs were grouped into three egg size categories i.e. Small (38-44 g), medium (45-52 g) and large (53-59 g). To study the impact of incubation period, eggs were stored at 21 ̊C temperature for three different time periods (fresh, 3 day and 6 day). It was observed that egg fertility was increased on 3rd day and decreased on 6th day as compared to 0 day. For small egg class, egg fertility was 95.55, 96.02 and 92.13% respectively, on 0, 3 and 6 day of storage. Similarly, for medium-sized egg class, fertility was 95.17, 95.64 and 90.28% and for large sized egg class, it was 91.11, 92.15 and 87.41% respectively, on 0, 3 and 6 day of storage. Embryonic mortality increased with increase in storage duration. For small egg class, egg mortality was 20.95, 17.56 and 24.87% respectively, on 0, 3 and 6 day of storage. Similarly, for medium-sized eggs class, mortality was 10.15, 8.45 and 12.63% and for large sized egg class, it was 29.30, 20.14 and 33.41% respectively, on 0, 3 and 6 day of storage. The egg fertility and mortality are affected by the storage period. For best hatchability, egg storage should not exceed 3 days.

In Vitro Nematocidal Properties from Two Extracts: Lippia graveolens Leaves and Delonix regia Flowers Against Eggs and Infective Larvae of Haemonchus contortus.

The objective of this study was to assay the ovicidal and larvicidal effects of two hydroalcoholic extracts (HA-E) and their aqueous fractions (Aq-F) and organic fractions (EtOAc-F) from Lippia graveolens (leaves) and Delonix regia (flowers) against the parasitic nematode Haemonchus contortus. The egg hatching inhibition test (% EHI) and mortality of infective larvae (% mortality) were used as biological models. The treatments of each plant (mg/mL, % EHI, and % mortality) were assigned as follows: HA-E (12.5-50, EHI; 25-200, mortality), Aq-F (6.25-25.00, EHI; 12.5-50, mortality), EtOAc-F (0.37-25, EHI; 3.12-50, mortality), negative controls (distilled water and methanol at 2% and 4%), and positive control (ivermectin at 5 mg/mL). Data were analyzed using a completely randomized design through an analysis of variance, considering the EHI and mortality percentages as the response variables. To identify the secondary metabolites, both plants were subjected to qualitative chemical analysis and HPLC. The results showed that both plants exhibited highly ovicidal and larvicidal effects. The bipartition in each HA extract allowed the increase of the anthelmintic effect in EtOAc-F, achieving a total ovicidal activity at 1.56 mg/mL and a larvicidal effect higher than 90% at 25 mg/mL. The qualitative chemical profile of both vegetal species identified alkaloids, flavonoids, condensed tannins, terpenes, and saponins. These results suggest that either L. graveolens leaves or D. regia flowers could be potential candidates for the control of parasitic gastrointestinal nematodes in small ruminants. However, in vivo studies with experimental animals to evaluate their possible toxicity and anthelmintic effect are necessary.

Activity of terpenes derived from essential oils against Sarcoptes scabiei eggs

BackgroundThe limited ovicidal activity of currently available acaricides is a significant obstacle to efficacious scabies treatment. Several essential oils or their respective components have proved to be active against the eggs of arthropods, mainly lice and ticks. Information on the activity of these oils and/or components against the eggs of mites remains very limited. The aim of this study was to assess the activity of six terpenes (carvacrol, eugenol, geraniol, citral, terpinen-4-ol and linalool) commonly found in essential oils against the eggs of Sarcoptes scabiei.MethodsSarcoptes eggs were exposed to paraffin oil containing 1, 2.5, or 5% of each terpene tested. After a 12-h exposure period, the eggs were washed and placed in paraffin oil for hatching. Embryonic development following treatment was assessed every day to determine the stage of developmental arrest.ResultsThe median effective concentration to obtain 50% egg mortality (EC50) was 0.5, 0.9, 2.0, 4.8, 5.1 and 9.8% for carvacrol, eugenol, geraniol, citral, terpinen-4-ol and linalool, respectively. The microscopic images of eggs after each treatment indicated that these six terpenes may act by penetrating through the aeropyles on the egg surface.ConclusionsIn conclusion, carvacrol, eugenol and geraniol possess significant ovicidal activities, which should be considered as promising ovicidal agents for the treatment of scabies.Graphical

Effectiveness of Entomopathogenic Fungi on Immature Stages and Feeding Performance of Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) Larvae.

Simple SummaryFall armyworm (FAW), primarily endemic to the United States, has posed a severe threat to maize cultivation globally in recent decades. To prevent maize from being harmed by FAW, various control strategies are used, including synthetic pesticides. Synthetic chemicals are still the most effective and widely utilized technique; nonetheless, these chemicals are hazardous to humans, biodiversity, and the environment, necessitating a desperate search for safe and long-term solutions. Entomopathogenic fungi (EPFs) are thought to be an essential alternate control tool for this invasive pest. The goal of this study was to determine the effectiveness of five entomopathogenic fungal isolates (Aspergillus sp. BM-3 and SE-2-1, Cladosporium tenuissimum SE-10, Penicillium citrinum CTD-24, and Beauveria bassiana ZK-5) against immature stages (eggs, neonates, and larvae) and feeding efficacy of first to sixth instar S. frugiperda larvae at 1 × 106, 1 × 107, and 1 × 108 conidia mL−1. Among the five tested fungal isolates, C. tenuissimum SE-10, P. citrinum CTD-24, and B. bassiana ZK-5 showed significant effects on egg mortality and significantly reduced the early third instar feeding efficacy of FAW larvae at the highest concentration level. These potent fungal isolates could be suitable candidates for developing biopesticides in an integrated manner to control the FAW population. By decreasing the hatchability of eggs and reducing the feeding ability of early first to third instar FAW larvae, the findings of this study could assist in managing this invasive pest in China and enhance maize crop output. However, further research is needed to evaluate and validate laboratory outcomes in real-world situations.Maize is a major staple crop in China, and the sustainable productivity of this primary crop has been recently threatened by fall armyworm (FAW), Spodoptera frugiperda, invasion. The five fungal isolates, Aspergillus sp. BM-3 and SE-2-1, Cladosporium tenuissimum SE-10, Penicillium citrinum CTD-24, and Beauveria bassiana ZK-5 were assessed for their efficacy in causing mortality against first to sixth instar eggs and neonate larvae seven days post-treatment, and their effects on the feeding performance of sixth instar S. frugiperda larvae at 48 h post-treatment at three concentrations (1 × 106, 1 × 107, and 1 × 108 conidia mL−1) were also assessed. The six instar S. frugiperda larvae were not susceptible to the five tested fungal isolates. However, B. bassiana ZK-5 caused the highest egg mortality of 40, 70, and 85.6% at 1 × 106, 1 × 107, and 1 × 108 conidia mL−1, respectively, followed by P. citrinum CTD-24 (30.6, 50, and 75.6%) and C. tenuissimum SE-10 (25.6, 40, and 55.6%). In addition, B. bassiana ZK-5 caused the highest neonate mortality of 54.3% at 1 × 108 conidia mL−1. B. bassiana ZK-5 and P. citrinum CTD-24 caused cumulative mortality, including 93.3 and 83.3% mortality of eggs and neonates, respectively, at 1 × 108 conidia mL−1. Furthermore, B. bassiana ZK-5 reduced the feeding efficacy of first to third instar S. frugiperda larvae by 66.7 to 78.6%, while P. citrinum CTD-24 and C. tenuissimum SE-10 reduced larval feeding by 48.3 to 57.1% at 1 × 108 conidia mL−1. However, these fungal isolates were less potent in reducing the feeding activity of fourth to sixth instar S. frugiperda larvae (>46% with B. bassiana at 48 h post-treatment). The tested fungal isolates could play an essential role as microbial biopesticides in suppressing the S. frugiperda population in China after further investigations on their efficacy are obtained in the field.

Identifying key threats to a refugial population of an endangered Hawaiian moth

Abstract The dramatic worldwide decline in insect biodiversity has highlighted the need for insect conservation. However, management is hindered by incomplete knowledge of what drives species mortality. Even when drivers are identified, it can be difficult to quantify their effects. Using data from six naturally occurring cohorts observed over 2 years, we created partial ecological life tables for Blackburn's sphinx moth, Manduca blackburni, a federally listed endangered moth endemic to the Hawaiian Islands. We identified mortality factors impacting eggs and quantified mortality for both eggs and larvae of M. blackburni. Life table analysis demonstrated that total mortality was above 99%, highlighting the severe threats faced by this critically endangered species. Disappearance, likely driven by invasive ants, and predation were the two primary causes of egg mortality. While egg mortality contributed the most to total mortality, apparent mortality was high for all developmental stages observed, indicating substantial risk throughout the moth's pre‐adult life cycle. Our results show that M. blackburni likely experiences unsustainably high mortality across its pre‐pupal life stages and highlight the dangers invasive predators pose for the focal species and naïve species in general. The threats facing M. blackburni may bear directly on other declining insect species and their management. Future conservation efforts should focus on mitigating the impacts of invasive ants and other arthropod predators to promote species recovery for this charismatic Hawaiian endemic.

Acaricidal efficacy of ultraviolet-C irradiation of Tetranychus urticae adults and eggs using a pulsed krypton fluoride excimer laser

BackgroundPulsed ultraviolet (UV)-C light sources, such as excimer lasers, are used in emerging non-thermal food-decontamination methods and also have high potential for use in a wide range of microbial decontamination applications. The acaricidal effect of an experimental UV-C irradiation device was assessed using female adults and eggs of a model organism, the two-spotted spider mite Tetranychus urticae.MethodsUV-C light was generated by a pulsed krypton fluoride excimer laser operating at 248-nm emission wavelength. The pulse energy and pulse repetition rate were 5 mJ and up to 100 Hz, respectively. The distance from the light source to the target was 150 mm; the target surface area was 2.16 cm2. The exposure time for the mites and fresh eggs varied from 1 to 4 min at 5–300 mW, which corresponded to UV doses of 5–80 kJ/m2. Post-irradiation acaricidal effects (mite mortality) were assessed immediately and also measured at 24 h. The effects of UV-C irradiation on the hatchability of eggs were observed daily for up to 12 days post-irradiation.ResultsThe mortality of mites at 5 and 40 kJ/m2 was 26% and 92%, respectively. Mite mortality reached 98% at 80 kJ/m2. The effect of exposure duration on mortality was minimal. The effect of irradiation on egg hatchability was even more significant than that on adult mite mortality, i.e. about 100% egg mortality at an accumulated dose of as little as 5 kJ/m2 for each exposure time.ConclusionsA high rate of mite mortality and lethal egg damage were observed after less than 1 min of exposure to 5 mJ UV-C pulsed irradiation at 60 Hz. Pending further developments (such as beam steering, beam shaping and miniaturisation) and feasibility studies (such as testing with mites in real-life situations), the reported results and characteristics of the UV-C generator (modulation of energy output and adaptability to varying spot sizes) open up the use of this technology for a vast field of acaricidal applications that require long-range radiation.Graphical

Comparative Analysis The Effect of Iodine, Ozone, and Peracetic Acid as A Disinfectant of Cantang Grouper Egg

Problems in the fish hatchery sector often occur such as high egg mortality or low quality of fish eggs. Optimizing biosecurity is one of the efforts to improve the quality of fish eggs, for example by adding disinfectants such as iodine, ozone, and peracetic acid. The use of chemical disinfectants will produce good results if the right dose, time, and commodity are used. In this study. This research aims (1) to determine whether the use of chemicals including iodine, ozone, and peracetic acid had an effect as a disinfectant to increase the hatching rate of grouper fish, (2) to determine the level of effectiveness and efficiency of the use of chemicals as a disinfectant. This research is an experimental research type. The research subjects included in the study were cantang grouper fish eggs at PT. Pakarti Daksa Segara who used the exploratory sampling method. The conclusion of this study indicates that there is an influence on the growth rate of the use of iodine, ozone and, peracetic acid chemicals as disinfectants of cantang grouper eggs and there is a comparison of the effectiveness and efficiency of the use of the three chemicals which includes the percentage of the hatching rate, the cost of the disinfectant material and the time, which is needed in the use of the disinfectant. Iodine has the best level of effectiveness from the comparison of hatching eggs of cantang grouper and peracetic acid is the most efficient type of chemical.