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Mosquitoes are insects of medical interest. They contribute to the transmission and spread of many viral and parasitic diseases. Various methods have been used to control mosquitoes such as conventional insecticides, which are widely used throughout the world and have a negative impact on the environment and targeted species. Predatory insects are significant for the biocontrol of various pests, including the important potential against the larval instars of mosquitoes. In this study, we tested the efficacy of five species Piona uncata Koenike, 1888; Notonecta glauca Linnaeus, 1758; Corixa punctata Illiger, 1807, Ilyocoris cimicoide Linnaeus, 1758; and Sympetrum striolatum Charpentier, 1840 against the fourth instars larvae of Culex pipiens Linnaeus, 1758, according to two exposure phases (Light phase, Twilight phase). The predation assays show a significant effect of tested species against mosquito larvae with the following decreasing order of efficacy: S. striolatum> N. gluca> P. uncata> I. cimicoides> C. pinctata. The early larval instars are the most favourable trophic choice of the five predatory species. On the other hand, we noticed a difference in the predation rate for each species during the two experimental periods. The light phase exhibits the highest predatory efficacy than the twilight phase. [ABSTRACT FROM AUTHOR]

Rhyzopertha dominica (F.) is considered as a major stored product pest. Conventional insecticides induce adverse effects on the environment. Plant derivative products constitute a promising alternative for pest control. The purpose of our research was to identify the chemical profile of essential oil (EO) extracted from Schinus molle L. (Anacardiaceae) and to evaluate the fumigant and the contact toxicity, and the repellent activity of this oil on adults of Rhyzopertha dominica F. (Coleoptera), a major pest in products that are stored around the world. The effects of this oil were examined on biochemical profile (energy reserves and Proteins), selective biomarkers like acetylcholinesterase (AChE), glutathione S-transferases (GST) and glutathione (GSH), and nucleic acids (DNA and RNA). Digestive enzymes were also investigated. The major chemical compounds identified by the GC-MS were α-phellandrene (16.613%), ß-phellandrene (12.104%), elemol (9.028%) and β-eudesmol (5.872%). Then, we evaluated the repellent activity, and also the effects in nutritional reserves and some biomarkers. This EO exhibited an insecticidal and repellent activity as a function of the exposure time and concentrations. Contact (LC50 at 24 h: 19.99 μL/mL) is the most effective mode of application compared to fumigation (LC50 at 24h: 174.30 μL/L air). S. molle EO was also investigated in digestive enzymes' activities (α-amylase, lipase, chitinase and protease). Our results revealed a decrease in both α-amylase, lipase, protease and chitinase activities in treated adults compared to controls. In addition, we noticed a neurotoxic activity of S. molle EO traduced by a decrease of AChE. An induction of the detoxification system was observed via a decrease in GSH rate and an increase in GST activity. Moreover, the treatment induces an alteration of biochemical profile of R. dominica adults. Lastly, essential oil was examined on nucleic acids. Results showed an increase in DNA and RNA amount in treated adults when compared with control. Due to their effective source of bioactive compounds, the EO from the studied plant could be used as an alternative strategy for the management of stored product pests. [ABSTRACT FROM AUTHOR]

Cadmium is a non-essential heavy metal in the biological system. In this study, we have highlighted to evaluate of the effect toxicity of cadmium chloride (CdCl2) against Marine Bivalve Donax trunculus L. (Mollusca, Bivalvia) under laboratory conditions. The acute bioassay tests at various gradient concentrations of cadmium (5, 7.6, and 10 mg/L) were performed to estimate lethal concentrations 50 (LC50 Concentration estimated that produces a 50% mortality in a test population over a specific period) and 90 (LC90) for 24, 48, 72, and 96 hours of exposure. 96h-LC50 and 96h-LC90 values are: 2.59 and 9.25 mg/L respectively. In addition, the sublethal concentrations (LC10 and LC25) at acute exposure (96 h) which are: 0.72 mg/L and 1.32 mg/L respectively, and their fiducial limits were investigated. The results obtained indicate that cadmium causes mortality in the species studied with a Concentration-response relationship. Thus, specimens of this marine bivalve were experimentally exposed to CdCl2 at concentrations corresponding to 96h-LC10 and 96h-LC50, to evaluate the effect of toxicity on catalase (CAT) and acetylcholinesterase (AChE) activities, followed by a recovery period during 4 days. Results showed that Cd inhibited AChE activity suggesting neurotoxicity disturbances. In addition, we observed a stimulation of the detoxification system as shown by an increase in catalase activity. Additionally, the transfer of individuals exposed to CdCl2 in untreated water showed a gradual restoration of the initial state. The data obtained from this study will provide useful information for understanding the toxicological process of CdCl2 in Donax trunculus. [ABSTRACT FROM AUTHOR]

The study is aimed at evaluating, under laboratory conditions, the side effects of a commercial formulation of diflubenzuron (Dimilin® 25 WP), which is an insecticide considered a chitin synthesis inhibitor, on some non-targeted aquatic species. The effect of two lethal doses of Dimilin LC10 (3.9 ng/L) and LC50 (16 ng/L) previously determined on fourth instar larvae of Culex pipiens L. 1758 were tested on some non-target aquatic species, abundant in the Lake of Birds (Northeast Algeria), a site classified under Ramsar Convention. The tested species belonged to two classes of invertebrates (Insects and Crustaceans). The insects included four species of Heteroptera: Corixa punctata Illiger, 1807, Notonecta glauca Latreille, 1802, Anisops sardea Latreille, 1802 and Plea minutissima Leach, 1817, and one species of Coleoptera Berosus signaticollis Charpentier,1825. For benthic crustaceans Daphnia magna Straus, 1820 (Cladocera) was retained. The results showed significant mortality recorded in C. punctata and medium mortality for B. signaticollis, A. sardea, N. glauca, P. minutissima and D. magna. Three-way ANOVA indicated highly significant effects of species, dose, and time. According to the sensitivity to Dimilin, the pairwise comparison of Tukey's test indicates that the most sensitive species was C. punctata followed by B. signaticollis and the least sensitive was N. glauca, followed by D. magna; then A. sardea and finally P. minutissima. [ABSTRACT FROM AUTHOR]

To select potential plant‐based insecticides, Tecoma stans (Bignoniaceae) leaf extract was screened for its larvicidal and delayed effects against a medically important mosquito species Culex pipiens L. (Diptera: Culicidae). First, gas chromatography–mass spectrometry (GC–MS) was conducted on T. stans extract, collected in ethanol for its chemical characterization and detection of active constituents. Second, insecticidal bioassays were made with several concentrations on earlier fourth instar larvae (L4) of Cx. pipiens for 24 h as recommended by WHO, in order to determine the lethality parameters of the tested extract. For that, two concentrations (LC30 and LC50) were applied on L4 for 24 h, and emerged adults were observed for their reproductive performance success like fecundity, percentage of hatching (fertility), body and gonads' volume. The biochemical composition of whole bodies of adults was investigated. Also, the specific activities of acetylcholinesterase (AChE) and glutathion S‐transferase (GST), biomarkers of neurotoxicity and detoxification, respectively, were also determined in L4 at different time intervals. Qualitative and quantitative phytochemical analysis (GC–MS) of the extract unveiled nine phytoconstituents with 2‐[4‐cyclohexylbutanoylamino]‐3‐chloro‐1,4‐naphthoquinone (36.24%) and 1,2‐Benzenedicarboxylic acid, mono(2‐ethylhexyl) ester (22.65%) as major components. The early L4 of Cx. pipiens were exposed to LC30 and LC50, and after 24 h, surviving individuals have been further reared until adult emergence. All over, T. stans leaves ethanolic extract impairs adults reproductive traits; it adversely affected gonad's size, fecundity and fertility, which negatively affected the survival of their offspring. Lipids contents were found to increase in both male and female adults. T. stans ethanolic extract increased GST activity and slightly inhibited AChE activity in L4. In conclusion, the ethanolic extract of T. stans could be a potential candidate used as a sustainable botanical insecticide for controlling mosquito. [ABSTRACT FROM AUTHOR]

Biological control is a means of preserving biodiversity and eradicating vector species of diseases such as Anopheles, which cause Malaria. The freshwater fish Gambusia affinis has been introduced into rivers around the world to control Culex larvae. This study aims to evaluate the responses of G. affinis from different sites due to their proximity to polluting sources by measuring growth (total height and weight), metric indices:gonadal-somatic index (GSI), hepato-somatic index (HSI) and condition index (K). It, also, investigated the response of two biomarkers: glutathion-S-transferase (GST) in the liver and acetylcholinesterase (AChE) in the head of adults females and males of G. affinis (Cyprinodontiforme: Poeciliidae). The species was collected during the reproduction period (sexual activity) in three sites different by their level of exposure to pollution sources: Messida River, a reference site located in a protected area, and two other site near to anthropogenic activities, El Karma and Sidi Brahim. The results obtained reveal that the Messida river site shows a better growth with the highest GSI and K compared to the other study sites. The data of the HSI revealed lower values at the same site. Biomarker measurements revealed higher GST induction, AChE inhibition, and a level higher MT at the Sidi Brahim. We conclude that the Sidi Brahim site is the most polluted followed by El Karma and finally the Messida River. The study of the different parameters in the two sexes revealed that the females of G. affinis were more robust than the males. [ABSTRACT FROM AUTHOR]

The aim of the present study was to test two bi-omarkers of environmental stress glutathione (GSH) and catalase (CAT), and to determine the main biochemical components (proteins, lipids, and carbohydrates) in the flesh of an edible fish, Liza au-rate, associated with environmental pollution in the Gulf of Annaba (northeast Algeria). Samples were collected monthly (December 2011 to November 2012) from two different sites, Sidi Salem a polluted site and Hnaya as a control site. Obtained results re-vealed an increase in CAT activity and a decrease in GSH rate in fish from the polluted site (Sidi Salem) compared to the control site (Hnaya). The biochem-ical analysis revealed a significant decrease in pro-tein, lipid and carbohydrate amounts in Sidi Salem comparatively to El Hnaya. In addition, the higher levels in biochemical components (protein, lipid and carbohydrate) are recorded in summer and the lower rates in winter at El Hnaya site, this is related to re-spectively the beginning and the end of the reproduction period. Thus, the difference noted between the two sites may be due to their pollution level. The level of pollution in Sidi Salem induced an oxidative stress associated with a mobilization of energetic metabolism for detoxification or for physiological processes such as growth or reproduction. Overall, obtained data indicate that L curate constitutes a useful tool as sentinel organisms for biomonitoring of aquatic pollution. [ABSTRACT FROM AUTHOR]

Results on the fumigant and repellent potency of azadirachtin (1%) and Citrus limonum essential oil 50:50 v/v (Aza-EO), applied simultaneously against the major stored grain pest Sitophilus granarius (L.), direct (mean mortality) and delayed effects on selected biomarkers catalase (CAT), glutathione S-transferase (GST) and glutathione (GSH) as well as on the main biochemical constituents (proteins, lipids, carbohydrates and their nutritional depletion index (NDI)) and synergism between Aza and EO are reported. Combination persistence was also investigated while seeking a possible synergistic effect. Aza-EO exhibited insecticidal activity against S. granarius with a significant repellence. Surviving treated adults (LC25 and LC50) showed an induction of detoxification enzyme activities of CAT and GST accompanied by a decrease in GSH rate. The tested combination affected the energy reserves with the strongest effect on protein and lipid contents. The synergitic ratios suggest a significant synergistic interaction between the two mix camponents. [ABSTRACT FROM AUTHOR]

The gulf of Annaba (East Algeria) has observed markedly increased levels of various pollutants. The objective of the current study was to examine the impact of these anthropogenic activities on the biochemical composition of an edible mollusk Donax trunculus. Thus, the levels of main biochemical constituents (proteins, carbohydrates, lipids) were measured at various times during a transplantation from a reference site (El Battah) to a contaminated site (Sidi Salem) for 21 days. Biochemical analyzes indicate changes at different times (0, 7, 14 and 21 days) during the transplantation period. At day 0, the levels of both carbohydrates, lipids and proteins from El Battah individuals were significantly higher compared to those from Sidi Salem. During transplantation, we notice comparable levels in transplanted individuals (El Battah to Sidi Salem) to those of Sidi Salem starting day 7 for proteins and day 14 for lipids and only at day 21 for carbohydrates, respectively. A two-way ANOVA (time, site) revealed significant effects of time, site. Conclusively, the contaminated environment at Sidi Salem site mainly by heavy metals affects the energy reserves of this mollusk species. [ABSTRACT FROM AUTHOR]

Spiromesifen (Oberon® 240 SC; concentrated solution; Bayer CropScience, Germany) a pesticide derived from spirocyclic tetronic acids, acts mainly though blocking lipid biosynthesis via acetyl-CoA carboxylase. However, its mode of action requires further analyses. This study aims to evaluate the sublethal effects of spiromesifen on the fruit fly Drosophila melanogaster. The treatment was carried out by topical application on newly moulted pupae using two concentrations (LD10 = 21.45 and LD25 = 39.53 μg a.i./pupa). Our results showed that the developmental duration of larvae and pupae were not significantly affected by treatment. However, spiromesifen caused delayed effects on flies that survived from treated pupae. Spiromesifen was found to decrease significantly both the morphometric measurements and the protein contents of ovaries. The protein pattern of ovaries showed a reduction in the number of protein bands affecting the progeny via vitellogenesis. Finally, compared to controls, spiromesifen decreased significantly the amounts of some cuticular hydrocarbons in treated female and male adults. Consequently, in response to the changes in cuticular hydrocarbons, their sexual behaviour was also affected. Our study brings new insights about the multiple effects and physiological consequences of disturbing lipid metabolism. [ABSTRACT FROM AUTHOR]

Biopesticides from botanicals are nowadays strongly encouraged for use in the program of controlling insect vectors of diseases and other harmful insects. The present study had the objective of determining the chemical composition of the essential oil of Mentha x piperita L. (Lamiaceae). We also evaluated the larvicidal and ovicidal activities of EO against Culex pipiens L. according to the World Health Organization (WHO) protocol. The chemical composition of EO from the aerial parts of peppermint was analyzed by gas chromatography-mass spectrometry GC/MS. The main components were menthol (28.66 %), limonene (19.01 %), and p-cymene (15.82 %). Also, this research found that M. x piperita EO showed larvicidal activity against fourth-instar larvae. Mortalities were recorded after 24, 48, and 72 h of treatment. It has potent larvicidal activity with increasing concentration and exposure time (LC50 values were 448.74; 181.97 and 152.05 ppm). Besides, EO showed excellent ovicidal activity, the results of which indicated that the hatchability of eggs treated with LC50 and LC25 is 18.13 % and 53.67 %, respectively. Furthermore, the study examines the efficacy of this oil on the glutathione S-transferase (GST) and acetylcholinesterase (AChE) activity of Cx. pipiens larvae treated with LC50 and LC90. This experiment has led to neurotoxic activity and stimulation of the detoxification system, as shown by AChE inhibition and GST induction respectively. In conclusion, M. x piperita EO is a natural larvicide and promising ovicide against Cx. pipiens. Therefore, it is recommended for use as a natural biocide in the implementation of effective mosquito control programs. [ABSTRACT FROM AUTHOR]

The dry aerial part of Rosmarinus officinalis, collected from Djebel Belkfif (Tébessa, North- Eastern, Algeria), were hydrodistilled in a Clevenger type apparatus and analyzed by GC and GC-MS. The larvicidal activity of the R. officinalis essential oil (EO) against the fourth instar larvae of Culex pipiens L. was determined after 24 hours of exposure according to the World Health Organization procedure. The R. officinalis EO effects, via application of two lethal concentrations (LC25 and LC50), were examined on morphometric parameters (weight and body volume) and main biochemical components (proteins, lipids, carbohydrates) at different exposure periods. Furthermore, glutathione-S-transferase (GST) activity and glutathione (GSH) rate were assessed as biomarkers of the detoxification system. The GC and GC-MS analysis led to the identification of 36 components representing 99.97 % of the total oil, in 1.9 % yield, with 1,8-cineole (44.34 %), camphor (16.74 %), α-pinene (10.07 %) and borneol (5.02 %) as the main components. Bioassay test revealed that R. Officinalis EO exhibited a larvicidal activity against fourth instar larvae at 24 hours (LC25, LC50 and LC90 values were 39.47, 51.33 and 86.77 ppm, respectively). When applied to its LC25 and LC50, EO induced a significant decrease of larvae morphometric parameters and disturbed energy reserves with a marked lipid decrease at different periods. Also, treatment-induced stimulation of the detoxification system is highlighted by GST activity increase and GSH level decrease. [ABSTRACT FROM AUTHOR]

Previous works has shown that the heavy metal pollution is major in the region of Annaba (Northeast Algeria). The aim of this study was to assess the impact of anthropogenic activities on soil quality using Lumbricus terrestris as a bioindicator. Soil samples and earthworms were collected during the autumn and spring at two sites: Sidi Amar located near to several industrial factories, while El Tarf situated in a rural area far from any anthropogenic contamination. The activities of glutathione S-transferase (GST) and acetylcholinesterase (AChE), biomarkers of oxidative stress and neurotoxicity, respectively were measured in earthmorms. The concentrations of heavy metals (Pb, Zn, Mn, and Fe) in soils and earthworm tissues were analyzed using atomic absorption spectrophotometry. The GST and AChE activities and the heavy metal concentrations were found to vary between sites and by season. Marked biomarker responses are noticed during the automn at the site closest to potential sources of pollution. These bioindicative stress response correlated with increasing metal concentration detected in soil and tissue samples. Thus, the difference recorded between the two sites is linked to their level of pollution. while the effect of seasons may be due to rains which promote leaching of heavy metals in soils. L. terrestris could serve as an useful biological indicator of soil contamination. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine seasonal variations of two biomarkers of oxidative stress, lactate dehydrogenase (LDH) and malondialdehyde (MDA), and their correlation with lipid-carbohydrate metabolism in the edible bivalve Donax trunculus. The samples were collected during the four seasons in 2014 at two sites in the Gulf of Annaba (northeast of Algeria): El Battah, which is some distance from any source of pollution, is considered a relatively clean site, while Sidi Salem is a site exposed to various sources of industrial, urban and harbour pollution. The results show a significant decrease in LDH activity in Sidi Salem D. trunculus compared with those at El Battah. Moreover, carbohydrate levels increased significantly in Sidi Salem. The MDA rate increased significantly in Sidi Salem relative to El Battah, while the amounts of lipid showed a significant decrease. The lipid and carbohydrate metabolism was negatively correlated with LDH and MDA. This difference between the two sites was observed for all seasons, with more effect in spring and summer. The results obtained showed that under stressful conditions due to anthropogenic factors, some physiological processes of D. trunculus can be affected. Thus, D. trunculus appears to be a suitable sentinel species for the assessment of ecotoxicological risk in the Gulf of Annaba. [ABSTRACT FROM AUTHOR]

Our study was aimed to assess the responses of three biomarkers, Acetylcholinesterase (AChE), Glutathi­one S-transferase (GST) and Malondialdehyde (MDA) in various tissues (gonad, mantle, digestive gland) of Donax trunculus (Bivalvia, Donacidae), a Mollusk Bivalve bioindicator of pollution in the Gulf of Annaba (Algeria). The samples were collected during the four seasons (winter, spring, summer, au-tumn) of 2016 year in three sites of Annaba gulf; Sidi Salem, site exposed to various sources of industrial and harbor pollution; Echatt, site subject to urban and agricultural wastes; and El Battah site distant from any source of pollution. The results showed a significant inhibition of AChE and induction of GST and MDA in individuals of Sidi Salem and Echatt as compared to El Battah with significant effects of both site and season. Indeed, the season effect was showed an inhibition of AChE and an induction of GST and MDA more pronounced during summer and spring compared to the other seasons. In addi­tion, the comparison between tissues revealed a more marked response in gonad than mantle and di­gestive gland. [ABSTRACT FROM AUTHOR]

Captopril is an inhibitor of angiotensin converting enzyme. It was tested in vivo by topical application on growth, development, whole body ecdysteroids and cuticular secretion in female pupae of The Mediterranean four moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). The compound is diluted in acetone and applied topically to newly emerged pupae (10μg/pupa). Results show that treatment exhibited various morphological abnormalities on adult exuviation. Captopril induced precocious and lethal adult exuviations, and caused several malformations. The enzyme-immunoassay measurements of ecdysteroids in whole body extracts revealed that the drug increase the amount of ecdysteroids. Observation under a photonic microscope on the cuticle secretion showed that the captopril increase the thickness of the old and the new cuticle. [ABSTRACT FROM AUTHOR]

Methoxyfenozide is an insect growth disruptor belonging to the class of nonsteroidal ecdysone agonists. In the present study, methoxyfenozide (23% emulsifiable concentrate) is evaluated against newly molted fourth‐instar larvae of Culex pipiens L. and Culiseta longiareolata Macquart (Diptera: Culicidae), aiming to investigate its possible effects on growth and development. Larvae are exposed for 24 h under standard laboratory conditions in accordance with World Health Organization recommendations. The product is found to exhibit insecticidal activity against the two tested mosquito species with a concentration–response relationship. Moreover, based on the lethal concentrations determined, methoxyfenozide is slightly more toxic against C. pipiens than C. longiareolata. Furthermore, fourth‐instar larva of the two mosquito species are treated using two lethal concentrations (LC50 and LC90) of methoxyfenozide, and then individual survivals (larvae, pupae and adults) from larval treatment are subjected to a biometrical and biochemical study. The compound is found to interfere with growth by reducing the larval and pupal development duration. Moreover, the body volume and the main biochemical contents (proteins, carbohydrates and lipids) from different stages are affected. The overall results suggest that the ecdysone agonist under investigation interferes with the development process and has potential for mosquito control. Deferred effects of methoxyfenozide (23% emulsifiable concentrate) at two lethal concentrations are examined against surviving individuals from larval treatment of Culex pipiens and Culiseta longiareolata.The moulting process is inhibited by methoxyfenozide and larvae of C. pipiens and C. longiareolata die after exuviation difficulties.Methoxyfenozide is found to disturb growth and development. The biometrical parameters and the metabolic reserves are also affected in these two mosquito species. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the chemical composition of the leaf essential oil of Thymus vulgaris cultivated in Tebessa (Northeast Algeria) and to evaluate its potential larvicidal activity against fourth instar larvae of Culex pipiens L., 1758. A total of 20 fourth instar larvae of C. pipiens were exposed to a variety of concentrations (25-200 ppm) in laboratory according to the standard procedure portrayed by World Health Organization. The effects were examined on the mortality, the activities of acetylcholinesterase (AChE), glutathione S-transferase (GST), gluhatione (GSH) rate and the biochemical composition (proteins, lipids, carbohydrates) of larvae body, respectively. The EO yield calculated from the dry matter of the aerial part of the plant was 1.58 %. Its chemical composition has been analyzed by the GC and GC-MS systems. A chemical constituent of 18 compounds was identified in the oils of T. vulgaris compounds representing to 99.94 %. Bioassay test revealed that this essential oil exhibited larvicidal properties as they could induce 100 % mortality in the larvae of C. pipiens at the concentrations of 200 ppm. Biomarker measurments in treated larvae (LC25 and LC50) revealed no effect on AChE activity, activation of detoxification system as showed by an increase in GST activity and a decrease in GSH rate. The biochemical compositions show that the essential oil affected the energy reserves with a marked effect on proteins and lipids. Lastly, our results proved the potential use of this natural material as an alternative to synthetic insecticides for controlling mosquitoes. [ABSTRACT FROM AUTHOR]

The present study aimed to assess, under laboratory conditions, the side effects of a trade formulation of diflubenzuron (Dimilin® 25 WP), a chitin synthesis inhibitor (CSI), on the biochemical composition of the cuticle and on the level of the biomarker of environmental stress glutathione (GSH), in a non-target species Palaemon adspersus (Rathke, 1837) (Crustacea, Decapoda). The insecticide was added to the shrimp's rearing water at two concentrations: 16 ng of active ingredient/L and 1 p,g/L. The shrimps were exposed to Dimilin from stage A (newly molted shrimp) to Stage C (Intermolt), where mineralization and deposition of the cuticular layers are completed. The results show a significant decrease (p < 0.05) in the amounts of chitin in the treated batches as compared to controls for both assays. Moreover, there was a significant difference (p< 0.05) in the cuticular proteins between treated and control individuals. However, the compound had no significant effect on the amounts of calcium salts. Regarding GSH level, there was a significant inhibition (p< 0.05) in treated individuals as compared to controls. Our results show an induction of the detoxification system and confirm the mechanism of action of Dimilin on chitin biosynthesis and indicate that this product can pose side-effects on non-target Arthropod organism like shrimps. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the impact of anthropogenic activities on the water quality of the Mellah lagoon using the shrimp Palaemon adspersus (Crustacea, Decapoda) as a bioindicator. The activities of glutathion S-transferase (GST) and acetylcholinesterase (AChE), biomarkers of oxidative stress and neurotoxicity, respectively, were measured in shrimps collected from each site. The samples were collected for two consecutive years (i.e. 2013 and 2014) and two seasons, summer and autumn, were considered in each year. Three sampling sites were chosen: the first one corresponds to the channel of the Mellah lagoon (site 1) is considered as reference site, the second one located in the output of El Mellah River (site 2) is characterized by their proximity to urban activities, and the last one situated in the output of R'kibet River (site 3) is exposed to agricultural and domestic activities. GST and AChE activities were found to vary between sites and by season and year. The results showed a significant induction in GST and also a significant inhibition in AChE activities in individuals from the sites 2 and 3 compared to those of the site 1. Indeed, marked responses are observed in the summer compared to autumn. Also, induction of GST and inhibition of the activity of AChE were higher in 2014 compared to 2013. The differences recorded between the sites studied in the Mellah lagoon are related to their level of pollution, while the seasonally and annually variations were due to the water supply by the Rivers during rainy periods. [ABSTRACT FROM AUTHOR]

Captopril is an inhibitor of angiotensin converting enzyme. We evaluate its effects on reproduction of e tia e niella (Lepidoptera), an important pest in stored products worldwide. The drug was applied topically (10 μg/pupa) on newly molted pupae. In follow-up experiment, the adults that survived from treated pupae were investigated for different reproductive event parameters. Captopril was found to decrease the duration of the oviposition period and the morphometric measurements of ovaries, the fecundity and the egg viability. Moreover, biochemical analyzes revealed that treatment reduced total protein, lipid and carbohydrate amounts of ovaries, respectively. Lastly, enzyme immunoassay measurements of ovarian ecdysteroids indicated that captopril increased the amounts of both total and free ecdysteroids, and decreased that of conjugated. The reduction of reproductive capacity was probably due to an interference of captopril with the vitellogenesis process and/or ecdysteroid biosynthesis. [ABSTRACT FROM AUTHOR]

Migratory locusts represent the most important crop pests in Africa and Asia. Because environmental damages are associated with the use of synthetic insecticides in locust and grasshopper control, new environmentally acceptable approaches are becoming increasingly important. The effects of gibberellic acid (GA3), a plant growth regulator, was investigated by topical application and ingestion on the reproductive physiology and ecdysteroids production of the migratory locustLocusta migratoriaat concentrations of 125, 625, 3125, 4125, 5125 and 6125 μg/mL. The treatment applied to adult females during the pre-ovipositional phase provokes a significant adverse influence on their reproductive potential. Indeed, GA3significantly reduced both fecundity and fertility. Gibberellic acid also caused disturbances in the incorporation of the hemolymph metabolites (proteins, carbohydrates and lipids) in the oocyte resulting in a significant reduction in their concentrations in the ovaries. Ecdysteroid production was measured by an enzymo-immunoassay. GA3, administered by ingestion to the adult females, significantly reduced the ecdysteroid titers in ovaries and freshly laid eggs. [ABSTRACT FROM PUBLISHER]

Azadirachtin was tested for its effects against First and second instars larvae of mosquito Culex pipiens pipiens (Diptera: Culicidae), laboratory reared larvae were exposed to 0.125 ; 0.250; 0.500 and 0.750 mg/ L of azadirachtin in laboratory of biology animal application, biology Department , university of Badji Mokhtar, Annaba, Algeria. Larvicidal assays were conducted according to standard World Health Organization (WHO) .The results have been exploited according to classic statistical methods. A linear correlation was revealed between concentration and larval mortality. At first stage, larval mortality increased from 45.83 % at 0.125 mg /L to 94.44 % at concentration 0.750mg /L of Azadirachtin in direct effect. The lethal concentration LC16, LC50 and LC90 in direct effect was measured as 0.056; 0.166 and 0.663 mg/L respectively. Cumulate mortality increased from 54.28% to 95.71% at 0.125mg/L and 0.750mg/L respectively. The LC16, LC50 and LC90 values for Azadirachtin were 0.040 ; 0,127 and 0.555mg/L respectively. At second stage, larval mortality increased from 39.66 % at 0.125 mg /L to 87.66 % at concentration 0.750mg /L of azadirachtin in direct effect, the LC16, LC50 and LC90 values was 0.063; 0.190 and 0.891 mg/L respectively. In indirect effect the mortality increased from 49.27% to 91.54% at 0.125mg/L and 0.750mg/L respectively, the LC16, LC50 and LC90 values was 0.041; 0.141 and 0.724 mg/L respectively. After a comparison between the two stages showed that the first stage is the most sensitive than the second stage. The results show that the azadirachtin is promising as a larvicidal agent against Culex pipiens pipiens naturally occurring biopesticide could be an alternative for chemical pesticides. [ABSTRACT FROM AUTHOR]

The article discusses a study which investigated the water quality in the gulf of Annaba in Algeria using selected biomarkers in the edible mollusc Donax trunculus (D. trunculus). The biomarker responses in the mollusc are said to be associated with environmental pollution. Variables measured in D. trunculus are mentioned including seasonal variations of the rate of malondialdehyde (MDA) and the specific activity of specific enzymes. Seasonal variations found in relation to environmental factors are discussed.