The effect of soil pollution with petroleum-derived substances on Porcellio scaber Latr. (Crustacea, Isopoda).

Presented research aimed at investigating the effect of short-term contact with petroleum-derived substances (PDSs) on life parameters of Porcellio scaber Latr. (Isopoda) and accumulation of polycyclic aromatic hydrocarbons (PAHs) in its body. The influence of presence of P. scaber on the total petroleum hydrocarbons (TPH) content in soil was also determined. The following objects were established: control-unpolluted soil; soil polluted with petrol; soil polluted with diesel fuel and soil polluted with used engine oil. Every pollutant was used in the amounts equal to 6000 mg of fuel/kg d.m. of soil 15 months earlier. In the laboratory, survival and body mass change of P. scaber reared in investigated soils were observed. The delivered food was not contaminated with PDSs. P. scaber reveals a considerable resistance in a short (4 weeks) contact with PDSs, evidenced as high survivability (from 68% on the soil polluted with engine oil to 77% on the soil polluted with diesel fuel) and undisturbed increase in body mass (on the level similar to control). It indicates the potential usefulness of this animal as a monitoring organism. No positive correlation was observed between TPH depletion in the soils contaminated with PDSs and P. scaber presence during 4 weeks of the experiment. PAH level in P. scaber bodies was generally very low (with the highest level of anthracene 0.40 µg/g of wet mass-after 4 weeks of rearing on the diesel fuel-contaminated soil), which may confirm the thesis about considerable abilities of isopods for biotransformation of these pollutants and low susceptibility to these xenobiotic penetration through integuments. However, a tendency for accumulation for phenanthrene and anthracene in conditions of soil polluted with diesel fuel was observed respectively 0.07 and 0.21 µg/g of wet mass for phenanthrene and 0.22 and 0.40 µg/g of wet mass for anthracene, observed successively in the 2nd and 4th week of rearing.

Growth Optimization and Rearing of Mealworm (Tenebrio molitor L.) as a Sustainable Food Source.

As a sustainable food source for humans, mealworms (Tenebrio molitor) have a great deal of potential, due to the fact that they have a very favorable nutritional profile and a low environmental impact. For meal production, feed formulation and optimization are important. The mealworm Tenebrio molitor (Coleoptera: Tenebrionidae) is the most consumed insect in the world. Mealworms were given a variety of diets, including wheat bran as constant diet supplemented with different levels of Ospor (Bacillus clausii) at 0.002 g, 0.004 g, 0.006 g, and 0.008 g; imutec (Lacticaseibacillus rhamnosus) at 0.2 g. 0.4 g, 0.6 g, and 0.8 g; fungi (Calocybe indica) at 250 g, 500 g, and 750 g; yeast (Saccharomyces cerevisiae) at 50 g, 100 g, and 150 g; and wheat bran (standard diet) were examined in complete randomized design (CRD). Different parameters, i.e., the larval, pupal, and adult weight, size, life span, and nutritional profile of mealworm were studied. When compared with other insect growth promoters, only wheat bran was discovered to be the most efficient. It generated the heaviest and longest larvae at 65.03 mg and 18.32 mm, respectively, as well as pupae weighing 107.55 mg and 19.94 mm, respectively, and adults weighing 87.52 mg and 20.26 mm, respectively. It was also determined that fungi (C. indica) and ospor (B. clausii) promoted faster larval development than yeast (S. cerevisiae) and imutec (L. rhamnosus). Larval mortality was also greater in the imutec (L. rhamnosus) and yeast (S. cerevisiae) diets than the others. No pupal mortality was recorded in all diets. Furthermore, the protein content of Tenebrio. molitor raised on a diet including fungi (C. indica) was the highest at (375 g), with a content of 68.31%, followed by a concentration of (250 g) with a content of 67.84%, and wheat bran (1 kg) (normal diet) with the lowest content at 58.91%. T. molitor larvae fed a diet supplemented with bacterial and fungal had lower fat and ash content than bran-fed T. molitor larvae (standard diet). Wheat bran (normal diet) had the highest fat at 16.11%, and ash at 7.71%. Hence, it is concluded that wheat bran alone or diet containing fungi (C. indica) and ospor (B. clausii) performed better in terms of growth, and these diets and protein content are recommended for the mass rearing of mealworms.

Sublethal and transgenerational effects of synthetic insecticides on the biological parameters and functional response of Coccinella septempunctata (Coleoptera: Coccinellidae) under laboratory conditions.

Synthetic insecticides have been an inevitable part of plant protection throughout the world. Sublethal effects of these chemicals on beneficial insect species are one of the contemporary issues these days. Using the age-stage, two-sex life table model, this study evaluated the sublethal and transgenerational effects of six synthetic insecticides (imidacloprid, thiamethoxam, lambda-cyhalothrin, cypermethrin, chlorpyrifos and profenofos) commonly applied to winter vegetables, on the fitness and predation of the seven-spotted ladybeetle, Coccinella septempunctata, which is an efficient predator of aphids worldwide. According to results, all insecticides at their sublethal doses (LC30) significantly suppressed the emergence of adults, adult weight, fertility and fecundity of the parental generation compared to control treatment. The larval stage was prolonged and oviposition, fecundity and total longevity of the adult beetles were decreased in unexposed progeny whose parents were exposed to sublethal doses of all insecticides. Moreover, the biological parameters of adults, including the intrinsic rate of increase (r), finite rate of increase (λ) and net reproductive rate (R 0) were significantly reduced when exposed to sublethal doses of insecticides. The predation rate of the F1 generation adults was also decreased after exposure to the sublethal doses of insecticides. However, chlorpyrifos, profenofos, lambda-cyhalothrin and cypermethrin exhibited more deleterious effects on the fitness and population parameters of beetles than imidacloprid and thiamethoxam.

Adverse effects of BDE-47 on life cycle parameters, antioxidant system, and activation of MAPK signaling pathway in the rotifer Brachionus koreanus.

2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) is widely dispersed endocrine disrupting chemicals (EDCs) in the aquatic ecosystem. Due to its devastating effect on marine organisms and insufficient database on toxicology, we investigated the adverse effects of BDE-47 on life parameters and antioxidant defense system following the reactive oxygen species (ROS) production in the monogonont rotifer Brachionus koreanus. In B. koreanus, the reduction in life cycle, fecundity, and population growth were observed in response to BDE-47. 50µg/L BDE-47 significantly reduced (P<0.05) life expectancy and net reproductive rate. In response to 10-50µg/L BDE-47 exposure, the oxidative stress was elicited via the generation of ROS, while the antioxidant related enzymes (e.g. glutathione S-transferase [GST] and glutathione reductase [GR]) have demonstrated significant activity levels (P<0.05) to further alleviate the oxidative stress in a concentration dependent manner. Furthermore, transcript profiles of antioxidant function (GST-A, -O, and -S1-S8)-related genes have shown the significant increase over 24h in response to BDE-47 (0, 10, 25, and 50µg/L). As for MAPK signaling pathway analysis, up-regulation of their activities was observed at 25µg/L BDE-47 but their activities have reduced at adult NOEC concentration of 50µg/L. This study provides a better understanding of the effects of BDE-47 on life parameters, molecular defense system, and activation of MAPK signaling pathway against generated oxidants in the rotifer.

Adverse effects of MWCNTs on life parameters, antioxidant systems, and activation of MAPK signaling pathways in the copepod Paracyclopina nana.

Engineered multi-walled carbon nanotubes (MWCNTs) have received widespread applications in a broad variety of commercial products due to low production cost. Despite their significant commercial applications, CNTs are being discharged to aquatic ecosystem, leading a threat to aquatic life. Thus, we investigated the adverse effect of CNTs on the marine copepod Paracyclopina nana. Additional to the study on the uptake of CNTs and acute toxicity, adverse effects on life parameters (e.g. growth, fecundity, and size) were analyzed in response to various concentrations of CNTs. Also, as a measurement of cellular damage, oxidative stress-related markers were examined in a time-dependent manner. Moreover, activation of redox-sensitive mitogen-activated protein kinase (MAPK) signaling pathways along with the phosphorylation pattern of extracellular signal-regulated kinase (ERK), p38, and c-Jun-N-terminal kinases (JNK) were analyzed to obtain a better understanding of molecular mechanism of oxidative stress-induced toxicity in the copepod P. nana. As a result, significant inhibition on life parameters and evoked antioxidant systems were observed without ROS induction. In addition, CNTs activated MAPK signaling pathway via ERK, suggesting that phosphorylated ERK (p-ERK)-mediated adverse effects are the primary cause of in vitro and in vivo endpoints in response to CNTs exposure. Moreover, ROS-independent activation of MAPK signaling pathway was observed. These findings will provide a better understanding of the mode of action of CNTs on the copepod P. nana at cellular and molecular level and insight on possible ecotoxicological implications in the marine environment.

Comparative life parameters of transgenic and wild strain of Aedes aegypti in the laboratory.

The release of genetically-modified Aedes aegypti males is considered an effective method of suppressing this vector of dengue. One of the prerequisites is the capability to mass produce the genetically-modified mosquito in the laboratory before release. To do so would necessitate the understanding of the lifecycle and parameters of the transformed strain. In this regard, comparative life-history parameters of a wild-type laboratory strain of Ae. aegypti (WT) and a genetically transformed Ae. aegypti (LA513) were studied in the laboratory. The following parameters were statistically indistinguishable in both strains: the number of eggs laid, the number of unhatched eggs, the egg-hatching rate, the duration of larval period in all four instars, larval survivorship, pupation, adult eclosion rate, gonotrophic cycle, adult fecundity, adult lifespan and offspring sex ratio. The basic life-history and growth rate of the genetically-modified Ae. aegypti was not affected by genetic manipulation and that its mating competitiveness will remain intact, which is important for the successful use of this technology.