Weight Of Larvae Research Articles

Biodegradation of polystyrene wastes by a newly reported honey bee pest Uloma sp. larvae: An insight to the ability of polystyrene-fed larvae to complete its life cycle

Commercial production of polystyrene (PS)-a persistent plastic has led to its accumulation as a major contaminant of the terrestrial and aquatic ecosystem. In this study, PS degradation capabilities of beeswax eating beetle larva Uloma sp. was evaluated and reported for the first time. The study also assesses its survivability and PS biodegradation rates. Effects of added nutrition on PS degradation and survivability were analysed by providing wax comb as co-feed (PS-WC). The egested frass of Uloma sp. larvae fed on Waxcomb (WC), PS and PS-WC were studied by evaluating the changes in physiochemical properties through FTIR, 1H NMR and TGA techniques. The post consumption weight loss percentage for WC and PS were 84.89 ± 2.6% and 41.6 ± 2.7%, respectively by a group of 100 beetle larvae. From the initial 2.5 g PS the total weight loss at the end of the 28-day feeding experiment was 1.04 ± 0.02 g with a consumption rate of 37.14 mg of PS per day per 100 larvae. Supplementing the PS feed of Uloma sp. larvae with WC facilitated enhanced PS degradation. PS degradation for larvae fed with PS-WC co-feed nearly doubled compared to larvae fed on PS alone. Twenty-eight-day survival rates for Uloma larvae fed on WC, PS and PS-WC was 89.2 ± 1.01%, 78.3 ± 1.4% and 84 ± 2.97%, respectively. The average weight of beetle larvae increased by 22% over a 28 day period when fed WC or PS-WC while, showed a 4.3% increase in PS alone and an 8.2% decrease in unfed larvae. The FTIR and 1H NMR analysis of egested frass showed evidence of depolymerization and oxidation confirming effective biodegradation of PS in the gut tract of Uloma beetle larvae. Uloma sp. larvae fed WC and PS completed all life cycle stages (larvae, pupae, beetles, egg), and the second generation had favorable PS degradation.

Toxicity of neonicotinoid insecticides on key non-target natural predator the larvae of Coccinella septempunctata in environmental

To evaluate the neonicotinoid insecticide tolerance in larvae of Coccinella septempunctata, which is a crucial focus of integrated pest management (IPM) programs, we used lethal and median lethal doses (LR50) of such insecticides and monitored insect mortality and development using a direct-contact method. The mortality tests show that neonicotinoid insecticides are highly toxic to larvae. The LR50 of pre-imaginal stage larvae are ranked as follows: 0.06% clothianidin GR > 0.06% dinotefuran GR > 5% acetamiprid EC > 2% thiamethoxam LDL > 70% imidacloprid WP > 350g/L imidacloprid SC. The mortality rates tended to stabilize after 72 h, even until the pre-imaginal stage. Hazard quotient (HQ) values indicate high potential risks of neonicotinoid insecticides on C. septempunctata in and off farmland. The LR50 dose affects the developmental duration, fourth-instar larvae weight, pupal weight, and weight increment of treated C. septempunctata. These results emphasize the importance of assessing side effects of chemical treatments on natural predator species serving as biological control agents for IPM strategies in agriculture.

Cultivation and biomass production of the diatom Thalassiosira weissflogii as a live feed for white-leg shrimp in hatcheries and commercial farms in Vietnam

This study investigated the biomass production process from the laboratory to the pilot scale in order to use the nutrient-rich biomass of the diatom Thalassiosira weissflogii as live feed for white-leg shrimp (Litopenaeus vannamei) at larval stages (zoeal, mysis, and postlarval) and in commercial production in hatcheries in Vietnam. Our results showed that T. weissflogii was successfully cultured in 1–2 L Erlenmeyer flasks, 0.2–3.5 m3 composite tanks, and 6.5 m3 tubular photobioreactors, with the highest cell density of 1.6 × 106 cells mL−1 reached after 6 days of culture. Under optimal culture conditions, the protein, lipid, and carbohydrate contents in this algal biomass were 13.2%, 20.0%, and 10.0% of dry cell weight, respectively. The fatty acid composition contains high amount of palmitic acid (C16:0, 43.11% of total fatty acid), and polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA, C20:5ω-3), approximated 16.5% of total fatty acid. In a 50 L larval rearing tank, at the optimal stocking density of 125 nauplii L−1, the survival percentage (75.55%), the total body length (from 5.376 ± 0.007 to 10.860 ± 0.030 mm), and weight (at from PL1 to PL12 stages) (from 0.145 ± 0.002 to 1.158 ± 0.005 g) of the white-leg shrimp larvae reached the highest values but the metamorphosis time (234 h) was shortest compared with the other stocking densities. Further, adding living T. weissflogii biomass to the diet of white-leg shrimp larvae at the nauplii 6 stage led to an increase in the body length, weight, and survival percentage of white-leg shrimp larvae of 21.17%, 35.7%, and 33% higher compared with those of larvae fed the control diet (without the addition of T. weissflogii), respectively. At the same time, the metamorphosis time of larvae (from Z1 to PL1) decreased by 4 h compared to the control group. In intensive ponds (area of 6400 m2 pond−1), using seed stocks at the postlarvae 12 stage that had been fed T. weissflogii, the final weight, yield, and survival percentage of the shrimp were increased by 7.3%, 14.2%, and 16.3%, respectively, compared with those of the control group. There were no statistically significant differences in the protein and carbohydrate contents in the shrimp flesh among the experimental and control group (p > 0.05). The lipid, omega-3, omega-6, and omega-9 fatty acid contents of shrimp flesh in experiment formula (per 100 g shrimp) were 1.21 g, 72.9 mg, 114 mg, and 86.1 mg, 11%, 29%, 21.6%, and 17.7% higher than that those in control, respectively. The obtained results show the great potential of using T. weissflogii as live feed on white-leg shrimp farms in Vietnam.

Effects of X-ray Irradiation on the Survival Rate and Weight of the Rhinoceros Beetle Larvae

Effects of X-ray Irradiation on the Survival Rate and Weight of the Rhinoceros Beetle Larvae

PENGARUH PEMBERIAN PAKAN ALAMI CACING Tubifex sp. TERHADAP PERTAMBAHAN PANJANG DAN BOBOT IKAN ZEBRA (Branchyndanio rerio)

One of the ornamental fishes which has a fairly good development prospect is zebra fish (Branchyndanio rerio). In the maintenance of zebra fish is needed special treatment in handling the fish larvae. The purpose of this study was to determine the effect of natural feeding on the Tubifex sp. silkworm to increase the length and weight of zebra fish larvae. This study contained 2 treatments, namely treatment A (feeding pellets in the morning and evening) and treatment B (feeding the Tubifex sp. silkworm in the morning and evening). Each treatment was carried out with 3 replications. Pellet feed and Tubifex sp. silkworm were given each ad libitum for 30 days. The results of this study showed that the percentage of fish seed increase in treatment B experienced a significant increase rather than just given pellet feed (Treatment A). For 30 days, the natural feeding of the Tubifex sp. in the morning and evening, fish larvae experienced a length increase of 13.78% and weight of 106.48%. This result is very different from fish larvae which were only given pellet feed in the morning and evening, which is only 12.31% for their weight and their length is fixed. The conclusion of this study is the natural feeding of Tubifex sp. have a significant effect on the length and weight of zebra fish larvae

Interaction between probiotic additive and perfluorobutanesulfonate pollutant on offspring growth and health after parental exposure using zebrafish

Perfluorobutanesulfonate (PFBS) pollutant and probiotic bacteria can interact to affect the reproductive outcomes of zebrafish. However, it is still unexplored how the growth and health of offspring are modulated by the combination of PFBS and probiotic. In the present study, adult zebrafish were exposed to 0 and 10 μg/L PFBS for 40 days, with or without dietary supplementation of probiotic Lactobacillus rhamnosus. After parental exposure, the development, growth and viability of offspring larvae were examined, with the integration of molecular clues across proteome fingerprint, growth hormone/insulin-like growth factor (GH/IGF) axis, calcium homeostasis, hypothalamic-pituitary-adrenal (HPA) axis and nutrient metabolism. Parental probiotic supplementation significantly increased the body weight and body length of offspring larvae. Despite the spiking of PFBS, larvae from the combined exposure group still had longer body length. RNA processing and ribosomal assembly pathways may underlie the enhancement of offspring growth by probiotic bacteria. However, the presence of PFBS remarkably increased the concentrations of cortisol hormone in offspring larvae as means to cope with the xenobiotic stress, which required more energy production. As evidenced by the proteomic analysis, the addition of probiotic bacteria likely alleviated the energy metabolism disorders of PFBS, thus allocating more energy for the larval offspring growth from the combined group. It was noteworthy that multiple molecular disturbances caused by PFBS were antagonized by probiotic additive. Overall, the present study elucidated the intergenerational interaction between PFBS and probiotic on offspring growth and health after parental exposure.

Effect of juvenile hormone–III and 20-hydroxyecdysone hormone on larval development of worker and drone honeybee Apis cerana indica (Fabricius) (Hymenoptera: Apidae)

Indian honeybee Apis cerana indica is polymorphic bee having queen, worker and drone castes. In honeybee each caste has its own developmental pattern and completes its development passing through egg larva, pupa and adult stages. Post-embryonic development of honeybee is controlled by juvenile hormone and 20-hydroxyecdysone. Present study find out the effects of juvenile hormone-III and 20-hydroxyecdysone on development of fifth instar larvae of worker and drone honeybee Apis cerana indica. Pattern of effects of both hormones on weight and length of worker and drone larvae were observed similar at 24 hrs and 36 hrs time interval but prominent changes in weight and length were seen in drone larvae as compared to worker larvae. Antagonistic effect of juvenile hormone-III and 20-hydroxyecdysone on total body protein was found in worker and drone larvae. Different effects of both hormones on worker and drone larvae suggested the different development timing and differed in physiology of worker and drone castes.

Net benefits of a mutualism: Influence of the quality of extrafloral nectar on the colony fitness of a mutualistic ant

AbstractAimExtrafloral nectar, a carbohydrate‐rich liquid, is the main plant‐based resource offered in exchange for ant protection. The positive results of this protection provided by ants are widely studied and supported; however, studies showing the benefits that ants and their colonies have from the resources offered by plants such as extrafloral nectar are scarce. Here, we evaluated how extrafloral nectar and artificial food resources with different nutrient concentration benefit short‐ and long‐term Camponotus crassus colony fitness (number and weight of individuals) and survival.MethodsWe conducted two sets of experiments: (1) in the field we attached artificial ant nests to plants with clogged and unclogged extrafloral nectaries; and (2) in the laboratory we offered artificial food resources with different carbohydrate–protein ratios to ant colonies. With these experiments, we evaluated the number and weight of queens, adult workers, pupae, larvae, and eggs, as well as the survival probability of the colonies.ResultsIn the first experiment, the short‐term provision of extrafloral nectar resulted in a larger number and weight of individuals with access to this resource. In the second experiment, regardless of time, the supply of more concentrated carbohydrate and nitrogen food increased ant colony fitness and survival. Conclusion: We provided new evidence that extrafloral nectar significantly benefits ant colonies. Our results corroborate the assertion that these relationships are reciprocally beneficial.

Body Size Plasticity of Weevil Larvae (Curculio davidi) (Coleoptera: Curculionidae) and Its Stoichiometric Relationship With Different Hosts.

Parasites obtain energy and nutrients from the host, and their body size is also usually limited by host size. However, the regulatory mechanisms that control the plasticity of parasite body sizes and the stoichiometric relationships with their hosts remain unclear. Here we investigated the concentrations of 14 elements (C, H, O, N, P, S, K, Na, Ca, Mg, Al, Fe, Mn, and Zn) in the acorns of three oak species (Quercus spp.), in their endoparasitic weevil (Curculio davidi Fairmaire) (Coleoptera: Curculionidae) larvae and in the larval feces, and the weight of weevil larvae within different hosts in a warm-temperate zone of China. Our results showed that the three acorn species exhibited significant differences in C, H, O, P, K, Mg, and Mn concentrations. However, in the weevil larvae, only P, Mn, and C:P ratio revealed significant differences. Weevil larvae preferentially absorbed and retained N, Zn, Na, and P, whereas Mn, K, Ca, and O were passively absorbed and transported. The weevil larvae weight was associated with acorn stoichiometry, and positively correlated with acorn size. Weevil larvae P decreased, but Mn and C:P increased with their weight, implying highly variable in somatic stoichiometry are coupled with the plasticity of body size. Interestingly, weevil larvae weight was negatively correlated with acorn infection rate, indicating small-size parasitic insects might have higher fitness level in parasite–host systems than larger-size ones. Our results suggest that variation in P, Mn, and C:P in parasites may play critical roles in shaping their body size and in improving their fitness.

Bioactivity of Spagneticola trilobata Flower Extract against Fall Army Worm Spodoptera frugiperda J. E. Smith

Fall armyworm ( Spodoptera frugiperda ) is a new pest that attacks maize plantations in Indonesia. Local farmers generally use synthetic pesticides to control the pest that can cause environmental and health problems, and in the future will trigger resistance of the pest to insecticide. This study aimed to determine the potential of Sphagneticola trilobata flower extracts on mortality, larval weight, weight of food consumption, and inhibition of feeding activity in S. frugiperda larvae. The research method is completely randomized design with 6 treatments and 3 replications. The treatments consisted of control treatments, S. trilobata flower extract 1%, 2%, 3%, 4%, and 5%. Mortality, larval weights and food consumption data were analyzed using analysis of variance. The results showed that the S. trilobata flower extract at the highest concentration of 5% resulted in larval mortality of 72.22. These results indicated that the S. trilobata flower extract was not effective against S. frugiperda. However, S. trilobata extract can influence other biological aspects, such as feeding activity and growth of S. frugiperda larvae. Tratment of 5% of S. trilobata extract resulted in weight of feed comsumption of 0.123 g with inhibition of feeding activity of 66.11%, and average weight of larvae of 0.048 g that were lower than control treatment.

Coordinated control of adiposity and growth by anti-anabolic kinase ERK7.

Energy storage and growth are coordinated in response to nutrient status of animals. How nutrient‐regulated signaling pathways control these processes in vivo remains insufficiently understood. Here, we establish an atypical MAP kinase, ERK7, as an inhibitor of adiposity and growth in Drosophila. ERK7 mutant larvae display elevated triacylglycerol (TAG) stores and accelerated growth rate, while overexpressed ERK7 is sufficient to inhibit lipid storage and growth. ERK7 expression is elevated upon fasting and ERK7 mutant larvae display impaired survival during nutrient deprivation. ERK7 acts in the fat body, the insect counterpart of liver and adipose tissue, where it controls the subcellular localization of chromatin‐binding protein PWP1, a growth‐promoting downstream effector of mTOR. PWP1 maintains the expression of sugarbabe, encoding a lipogenic Gli‐similar family transcription factor. Both PWP1 and Sugarbabe are necessary for the increased growth and adiposity phenotypes of ERK7 loss‐of‐function animals. In conclusion, ERK7 is an anti‐anabolic kinase that inhibits lipid storage and growth while promoting survival on fasting conditions.

Efficiency of some plants powder mix as a dietary supplement for silkworm (Bombyx mori)

Bombyx mori L. is one of the most economically important insects because of its production of silk. In this study, we investigated the effect of four plants powder mix on larvae weight, silk gland weight, cocoon parameters and fecundity of moths in two hybrids (local and imported) of silkworm. The most desirable effects (increased final larvae weight by over 8.93%, silk gland weight by over 37.45%, cocoon shell weight by over 39.84% and No. of eggs by over 28.93%) was obtained by treatment of mulberry leaves with (M2) in local hybrid. Meanwhile in imported hybrid the most desirable effects (increased final larvae weight by over 3.75%, silk gland weight by over 51.29%. cocoon shell weight by over 22.17% and No. of eggs by over 55.87%) was got by treatment of mulberry leaves with (M3) and feed it to the larvae. According to the results, It can enrich the nutrient quality of mulberry leaves provided to the silkworm by adding such plant materials, which lead to raising the efficiency of larvae productivity, increasing the quantity and quality of cocoons, and then improving the production of silk.

Larvicide and insecticide activity of the essential oil of Ocimum sanctum var. cubensis in the control of Musca domestica (Linnaeus, 1758), under laboratory conditions

Essential oils have been considered as an important alternative facing synthetic pesticides. The control of the species Musca domestica is very important for public health due to their role as vector associated with Vibrio cholerae, Salmonella and Shigella, among other pathogens. The objective of this work was to evaluate the larvicidal and insecticidal efficacy of the essential oil of Ocimum sanctum var. cubensis, in the control of Musca domestica and its effect on the post-embryonic development of this species. The essential oil was applied topically in six concentrations to newly hatched larvae (1μL / larva). Mortality, interval length of each development period, as well as the weight of mature larvae were analyzed. An insecticidal bioassay was also carried out in adult flies. The essential oil of O. sanctum caused a slight reduction in the larval and pupal period for some of the concentrations evaluated. The time of development of the newly hatched larvae until the adult period was shortened in all the concentrations analyzed. The larvae of the control group were the heaviest. The effectiveness of the product in the control of the larvae of the flies of the species M. domestica was greater than 50%, except for those larvae treated with 80.25 mg/mL of the essential oil. The lethal concentration for adult insects LC50 was estimated at 9.41μg. Results demonstrated that the essential oil of O. sanctum has effect in all stages of the life cycle of M. domestica, extolling its potential as an effective insecticide against this species.

Features of rainbow trout farming technology in PE “Zakhidna Rybna Kompania”, for feeding with Aguafeed Fischfutteer

The production of trout products in ponds and aquaculture farms is based on modern and long-term plans for technology and intensification of production, through the introduction of the latest approaches, by borrowing the experience of leading foreign producers, expanding production areas and sectoral investments. The main indicator that characterizes the efficiency of fisheries and reflects the state of production and the level of its economic indicators. is fish productivity Growing trout in aquaculture in a closed water supply is associated with high planting densities per unit area, the use of high-protein granular feed, which must fully meet the needs of fish in all necessary nutrients to ensure a balanced diet. In modern farms for feeding trout use high-protein feed mixtures in the form of grits and pellets. The dynamics of the intensity of growth and development of rainbow trout mainly depends on the location of the farm, the quality of the water supply source, the feeding regime of fish and the quality of feed. Therefore, the aim of the work was based on a review of literature sources and analysis of economic activity of the studied farm to give a general description of trout feed, Aquafeed Fischfutter, used for fish feeding, and determine their effectiveness, taking into account geographical location and abiotic and biotic factors . In addition, the study fish performance when feeding these feeds. Conduct research on the growth rate of rainbow trout, changes in weight and length of larvae, fry, yearlings and commercial fish, in tray, pool and pond cultivation. Develop a scheme for growing all age groups of trout on these feeds. Establish indicators of quality, nutritional value, feed ratio of starting, growth and production feeds. To give an objective assessment of their impact on the growth of larvae, fry, yearlings and commercial rainbow trout in the conditions of trout farming PE “Zakhidna Rybna Kompania”, Perimyshlyany district, Lviv region. The conducted research gives the basis to claim that this compound feed guarantees high daily gain. Being a high-energy feed, its use does not lead to obesity of fish. With intensive feeding, a good ratio of price and productivity of farmed fish is realized. The risk of contamination of water bodies and fish is very low, due to the low phosphorus content and good digestibility of feed – 1.1 kg of feed/kg of fish growth. The feed corresponds to the best world indicators in accordance with buoyancy and stability in water.

Diversity, Composition and Functional Inference of Gut Microbiota in Indian Cabbage white Pieris canidia (Lepidoptera: Pieridae).

We characterized the gut microbial composition and relative abundance of gut bacteria in the larvae and adults of Pieris canidia by 16S rRNA gene sequencing. The gut microbiota structure was similar across the life stages and sexes. The comparative functional analysis on P. canidia bacterial communities with PICRUSt showed the enrichment of several pathways including those for energy metabolism, immune system, digestive system, xenobiotics biodegradation, transport, cell growth and death. The parameters often used as a proxy of insect fitness (development time, pupation rate, emergence rate, adult survival rate and weight of 5th instars larvae) showed a significant difference between treatment group and untreated group and point to potential fitness advantages with the gut microbiomes in P. canidia. These data provide an overall view of the bacterial community across the life stages and sexes in P. canidia.

Akuakültür için Yeni Bir Tür: Sargoz Balığı (Diplodus sargus)

Sargoz balığı (Diplodus sargus) Akdeniz’de ticari değeri olan ve kontrollü şartlar altında yetiştiriciliği yapılabilecek deniz balığı türlerinden biridir. Bu çalışmada, sargoz balığı damızlıklarından döllenmiş yumurta, larva, yavru elde ederek türün kuluçkahane performansının araştırılması amaçlanmıştır. Çalışmada 8 adet dişi, 5 adet erkek damızlık balık kullanılmıştır. Örneklenen 1 g yumurta örneğinde 1248±13,47 adet yumurta olduğu tespit edilmiştir. Elde edilen 946,19±33,85 µm çapındaki yumurtaların 209,35±11,65 µm çapında tek yağ damlasına sahip oldukları gözlenmiştir. Yumurtaların 21,5±0,5°C’de ‰38 tuzlulukta 40. saatte açılmaya başladığı, açılma oranının ise %93,33±1,15, olduğu saptanmıştır. Ön beslemede yeşil su tekniği kullanılmıştır. Prelarvaların 5. günde %100 oranında yem almaya başladıkları tespit edilmiştir. Larvalar hava kesesi oluşumuna 6. günde başlamışlardır. Larvaların boyları ve ağırlıkları sırasıyla 55. günde 25,7±2,49 mm ve 255,8±6,6 mg olarak ölçülmüştür. Yaşama oranı %81,33±0,57 SGR oranı ise %10,79±0,12 olarak tespit edilmiştir.

Effect of Beauveria bassiana Fungal Infection on Survival and Feeding Behavior of Pine-Tree Lappet Moth (Dendrolimus pini L.)

Research highlights: The pine-tree lappet moth, Dendrolimus pini, can cause serious needle defoliation on pines with outbreaks occurring over large geographical areas. Under laboratory conditions, the promising potential of the naturally occurring entomopathogenic fungus Beauveria bassiana was tested against D. pini larvae as a biological control method. Background and objectives: The aim of this study was to investigate the most effective concentration and treatment dose of B. bassiana conidial suspension and how it affected the survival and feeding behavior of the pest. Materials and methods: The first experiment applied the fungal suspension directly on the back of selected larvae, and in the second experiment, sporulating cadavers obtained in the first experiment were placed into Petri dishes with healthy individuals. Different doses per larvae [µL] and spore suspension concentration [spores/µL]) were used. The second experiment was designed to investigate the horizontal transmission of fungi by exposing individual caterpillars to a cadaver covered in B. bassiana mycelia. Mortality rates were analyzed by Chi-squared tests using absolute values for total mortality and B. bassiana- attributed mortality. The lethal time and feeding-disruption speed were analyzed with parametric and non-parametric tests with the aim to determine whether statistically significant differences were observed between treatments. Results: Analysis of lethal time revealed that the 20 µL dose and 7.9 × 104 concentration yielded highest mortality, but also the average dieback rate of 9.4 days was significantly faster compared to all other treatments. In order to see whether insects stopped feeding after infection with B. bassiana, larvae weight loss was examined. Results showed that effective treatments induced change in the feeding behavior of infected larvae. The feeding disruption caused by the 20 µL treatment occurred on average 5.5 days after exposure or 3.9 days before the final dieback of larvae.

Titanium dioxide nanoparticle affects motor behavior, neurodevelopment and axonal growth in zebrafish (Danio rerio) larvae

More attention has been recently paid to the ecotoxicity of titanium dioxide nanoparticles (nano-TiO2) owing to its common use in many fields. Although previous studies have shown that nano-TiO2 is neurotoxic, the mechanism is still largely unknown. In the present study, zebrafish embryos were exposed to 0.01, 0.1, and 1.0 mg/L nano-TiO2 and 1.0 mg/L micro-TiO2 for up to 6 days post-fertilization (dpf). Exposure to 1.0 mg/L nano-TiO2 significantly decreased the body length and weight of zebrafish larvae; however, the hatching and mortality rate of zebrafish embryos did not change. Behavioral tests showed that nano-TiO2 exposure significantly reduced the swimming speed and clockwise rotation times of the larvae. The results revealed that nano-TiO2 treatment adversely affected motor neuron axon length in Tg (hb9-GFP) zebrafish and decreased central nervous system (CNS) neurogenesis in Tg (HuC-GFP) zebrafish. Additionally, real-time polymerase chain reaction analysis demonstrated that genes associated with neurogenesis (nrd and elavl3) and axonal growth (α1-tubulin, mbp, and gap43) were significantly affected by nano-TiO2 exposure. In conclusion, our study demonstrated that early-life stage exposure of zebrafish to nano-TiO2 causes adverse neural outcomes through the inhibition of neurodevelopment and motor neuron axonal growth.

Antifeedant Activities of Organic Fractions from Cestrum parqui Leaves on the Red-Haired Bark Beetle Hylurgus ligniperda

Hylurgus ligniperda is one of the most important quarantine forest insects associated to pine (Pinus radiate D. Don) logs exported from Chile. Methyl bromide fumigation has been the prominent control method. As the use of this synthetic insecticide leads to serious environmental problems, research to find alternative treatments is urgently needed for the Chilean forestry sector. Hence, plant secondary metabolites have been considered as an alternative for its control. Therefore, the objective of this work was to assess the feeding behavior of H. ligniperda through the artificial diet supplemented with organic fractions obtained from Cestrum parqui leaves. Organic extracts were obtained using a Soxhlet extraction. Non-choice tests were developed for testing the antifeedant activity shown by the organic fractions on adults, and 5th and 6th instar larvae of H. ligniperda. All the extracts tested elicited a decrease in the weight of unsexed H. ligniperda adults, and the effects were dose-dependent. Male beetle weight gain was reduced strongly by chloroform extracts and ethyl acetate elicited a weight increase of female and from the fifth and sixth instar larvae weight. Saponin extract elicited a reduction of the weight in male and female. Finally, the weight of both instar larvae was reduced by chloroform and saponin extract. C. parqui leaf extracts show a great potential for being used for controlling H. ligniperda and thus to diminish the use of harmful synthetic pesticide.

Parental Microbiota Modulates Offspring Development, Body Mass and Fecundity in a Polyphagous Fruit Fly.

The commensal microbiota is a key modulator of animal fitness, but little is known about the extent to which the parental microbiota influences fitness-related traits of future generations. We addressed this gap by manipulating the parental microbiota of a polyphagous fruit fly (Bactrocera tryoni) and measuring offspring developmental traits, body composition, and fecundity. We generated three parental microbiota treatments where parents had a microbiota that was non-manipulated (control), removed (axenic), or removed-and-reintroduced (reinoculation). We found that the percentage of egg hatching, of pupal production, and body weight of larvae and adult females were lower in offspring of axenic parents compared to that of non-axenic parents. The percentage of partially emerged adults was higher, and fecundity of adult females was lower in offspring of axenic parents relative to offspring of control and reinoculated parents. There was no significant effect of parental microbiota manipulation on offspring developmental time or lipid reserve. Our results reveal transgenerational effects of the parental commensal microbiota on different aspects of offspring life-history traits, thereby providing a better understanding of the long-lasting effects of host–microbe interactions.