Fungal Biotransformation of Hazardous Organic Compounds in Wood Waste.

A diverse spectrum of organisms, such as fungi, bacteria, and actinomycetes, can degrade and transform organic matter, including wood, into valuable nutrients. A sustainable economy has the goal of efficiently using waste as raw materials, and in this optic, it uses biological preparations more and more often, supporting the decomposition of lignocellulosic waste. With reference to wood wastes, which are produced in a substantial amount by the forest and wood industry, one of the possibilities to biodegrade such lignocellulosic material is the composting process. In particular, microbiological inoculum containing dedicated fungi can contribute to the biodegradation of wood waste, as well as the biotransformation of substances from the protection of wood, such as pentachlorophenol (PCP), lindane (hexachlorobenzene) and polycyclic aromatic hydrocarbons (PAHs). The purpose of this research was to produce a literature review in terms of the selection of decay fungi that could potentially be used in toxic biotransformation unions. The findings of the literature review highlighted how fungi such as Bjerkandera adusta, Phanerochaete chrysosporium, and Trametes versicolor might be ingredients of biological consortia that can be effectively applied in composting wood waste containing substances such as pentachlorophenol, lindane, and polycyclic aromatic hydrocarbons (PAHs).

Grape seed alleviates lindane-induced oxidative stress and improves growth performance, caecal fermentation and antioxidant capacity in growing rabbits.

This study evaluated the protective effect of grape seed on performance, caecal characteristics, blood metabolites and liver antioxidant status in lindane-treated rabbits. Four-week-old New Zealand White rabbits (n = 96) with an initial body weight of 0.750 ± 0.23 g were randomly divided into four groups (n = 24). One group was the control received only corn oil orally, while group L were received lindane daily via gavage in corn oil (4 mg/kg BW; 1/50 LD50 for oral dose), group GS was treated with 50 g grape seed /kg diet, and group LGS treated with a combination of both L and GS for 98 days. Results revealed that final body weight (FBW), average daily gain (ADG), dry matter intake and feed efficiency (FE) were similar between GS and control groups, and achieved the highest FBW and ADG, and the best FE. Caecum pH of the L group increased, while the caecum pH of the GS group decreased sharply. There was a significant increase in the concentration of total VFA, acetic acid, propionic acid and NH3 -N in the GS group, but butyric acid level decreased. GS treatment resulted in a significant increase in the concentrations of total protein, albumin and AChE. GPx, GST, CAT and SOD activity decreased, but TBARS activity significantly increased in the group L, while GS caused a significant elevation of antioxidant activity in the liver. These results confirm that the antioxidant compounds present in grape seed can alleviate the oxidative stress caused by lindane-induced hepatotoxicity and could be a useful supplement to maintain health and improve performance in rabbits.

Influence of destructive bacteria and red clover (trifolium pratense L.) on the pesticides degradation in the soil.

Lindane and DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) are pesticides from the group of persistent organic pollutants. These compounds, due to lipophilic properties, accumulate in tissues of organisms, are transmitted through the food chain and ultimately threaten human health. The long-term use of pesticides led to soil and water pollution. Microbial degradation of organochlorine compounds is the most eco-friendly method of polluted soil recultivation. Effective degradation of lindane and DDT soil pollution under the influence of introduced destructive bacteria was shown in the laboratory conditions. The concentration of lindane in the soil decreased by 75% and of DDT-by 56% in 30 days. The red clover seedlings increased pesticides degradation in the soil by 20%. The destruction of pesticides in soil was more intense than in the mineral medium. The DGGE analysis of microorganism associations introduced in contaminated soil was possible to follow the survival of the introduced associations. The use of microorganisms-destructors of organochlorine compounds, and plants as well as the biodegradation potential of the soil is a promising direction in the recultivation of polluted soils.

Biodegradation of technical hexachlorocyclohexane by Cupriavidus malaysiensis.

Lindane (γ-Hexachlorocyclohexane) has been used extensively as a pesticide all over the world. The production of Lindane entails the formation of four major Hexachlorocyclohexane (HCH) isomers, that is, alpha, beta, gamma, and delta as muck. These have been used as Technical HCH in developing countries as an inexpensive alternate source. However, HCH isomers pose a severe environmental hazard due to their highly persistent nature and toxicity. In this study, the effect of HCH application on the soil microbial diversity was studied. The species which could persist even after prolonged exposure at high HCH concentration, was isolated, screened, and enriched as potential t-HCH degraders. The selected isolate could degrade 88.05%, 92.19%, 91.54%, and 82.85% of the alpha, gamma, beta, and delta isomers, respectively at 100 mg/L HCH concentration. Identification of the isolate by 16s rRNA sequencing was similar to Cupriavidus malaysiensis. To the best of the authors' knowledge, this is the first study to observe this particular strain's ability to simultaneously degrade the four isomers, especially the most recalcitrant beta isomer. Therefore, the degradative capability of this strain, as a sole carbon source at higher HCH concentration (100 mg/l), can be exploited for bioremediation of HCH contaminated sites.

Association between toxic organochlorine levels in human serum and systemic lupus erythematosus.

Organochlorines (OCs) are groups of highly toxic pesticides with known immunotoxicity. The present work aimed to study the potential association between serum residues of OCs and the risk of developing systemic lupus erythematosus (SLE) as well as correlating to the clinical-laboratory manifestations in a sample of Egyptian SLE patients. A cross-sectional study was conducted on 132 patients environmentally exposed to OCs. Patients were diagnosed as SLE based on the American College of Rheumatology (ACR) revised criteria. Systemic Lupus Erythematosus Disease Activity Index-2000 (SLEDAI-2K) score was calculated to stratify the disease severity. Blood and urine samples were collected to measure the levels of OCs, serological markers, and urinary protein. The most frequently detected OCs were p,p'-DDE; lindane; and hexachlorobenzene (HCB). The risk of developing SLE was significantly associated with detected p,p'-DDE and HCB (B value 7.704 and 14.33, respectively). Hexachlorobenzene, in addition, was significantly associated with increased SLEDAI-2K score and polycythemia. Lindane was significantly associated with hypocomplementemia, cardiac manifestations of SLE, anemia, and leucopenia. In conclusion, the detected OCs p,p'-DDE and HCB are associated with increased risk of SLE in Egyptian patients and correlates to the manifestations of disease severity.

Reactivity and reaction mechanisms of sulfate radicals with lindane: An experimental and theoretical study.

Advanced oxidation technologies (AOTs) have been intensely used to eliminate various organic pollutants in engineering waters. In this context, we investigated the kinetics and mechanisms of the sulfate radical (SO4-)-mediated degradation of lindane in UV/peroxydisulfate system, and compared results with previous studies on SO4--based AOTs for destruction of lindane. The second order rate constant (k) value between SO4- and lindane was determined to be (8.95 ± 0.29) × 106 M-1 s-1via competition kinetics using p-cyanobenzoic acid as reference compound, which is close to the theoretically calculated value of 4.41 × 107 M-1 s-1, that was performed at SMD/M05-2X/6-311++G**//M05-2X/6-31+G** level of theory using density functional theory (DFT) approach. H-atom abstraction pathway was calculated to be thermodynamically favorable and kinetically dominant. In the combined experimental and theoretical study, we aim for a better understanding on the degradation kinetics and mechanisms of lindane, serving as a starting point for more attention to SO4--mediated degradation kinetics of cycloaliphatic compounds in future.

Lindane degradation in wet-dry cycling soil as affected by aging and microbial toxicity of biochar.

This study determined the degradation of lindane in soil amended with biochar to evaluate the effects of biochar aging and microbial toxicity. Two biochars were prepared at 400 and 600 °C (BC400 and BC600) and subjected to acid washing to remove nutrition (WBC400 and WBC600). After 89 days of incubation under the alternate "wet-dry" conditions, scanning electron microscopy showed that acid washing rendered biochars especially susceptible to aging with structural collapse and fragmentation, with less surface covering. Aging impeded the release of toxic substances in BC400 and BC600 with reduced toxicity to degrading microorganisms. Lindane degradation was somewhat stimulated by biochar nutrition but mainly inhibited by adsorption. Acid washing facilitated the release of toxic substances and additionally reduced lindane degradation. The variations in fatty acid saturation degree (SFA/UFA) in soils confirmed the microbial toxicity of 5% WBC400 > 5% BC400 > 5% BC600 > 5% WBC600. High-throughput DNA sequencing showed that biochar delayed the formation of dominant degrading microbial communities in soil. Lindane degradation was completed by joint Sphingomonas, Flaviolibacter, Parasegetibacter, Azoarcus, Bacillus and Anaerolinaea. These findings are helpful for better understanding the effect of biochar in soil on long-term degradation of persistent organic pollutants.

Rapid and Sensitive Quantification of the Pesticide Lindane by Polymer Modified Electrochemical Sensor.

Lindane is documented by the Environmental Protection Agency (EPA) as one of the most toxic registered pesticides. Conventional detection of lindane in the environment requires manual field sampling and complex, time-consuming analytical sample handling relying on skilled labor. In this study, an electrochemical sensing system based on a modified electrode is reported. The system is capable of detecting lindane in aqueous medium in only 20 s. The surface of a conventional carbon electrode is modified with a film of conductive polymer that enables detection of lindane down to 30 nanomolar. The electrode modification procedure is simple and results in a robust sensor that can withstand intensive use. The sensitivity of the sensor is 7.18 µA/µM and the performance was demonstrated in the determination of lindane in spiked ground water. This suggests that the sensor is potentially capable of providing useful readings for decision makers. The rapid and sensitive quantification of lindane in aqueous medium is one step forward to new opportunities for direct, autonomous control of the pesticide level in the environment.

Comparison of the efficacy of tea tree (Melaleuca alternifolia) oil with other current pharmacological management in human demodicosis: A Systematic Review.

Various treatments are found to be moderately effective in managing Demodex-related diseases except tea tree oil (TTO) and terpinen-4-ol (T4O), which showed superior miticidal and anti-inflammatory effects in numerous clinical studies. Their possible effects include lowering mite counts, relieving Demodex-related symptoms, and modulating the immune system. This review summarizes the current clinical topical and oral treatments in human demodicosis, their possible mechanisms of action, side-effects and resistance in treating this condition. TTO (especially T4O) is found to be the most effective followed by metronidazole, ivermectin and permethrin in managing the disease. This is because TTO has anti-parasitic, anti-bacterial, anti-fungal, anti-inflammatory and wound-healing effects. Furthermore, nanoTTO can even release its contents into fungus and Pseudomonas biofilms. Combinations of different treatments are occasionally needed for refractory cases, especially for individuals with underlying genetic predisposal or are immuno-compromised. Although the current treatments show efficacy in controlling the Demodex mite population and the related symptoms, further research needs to be focused on the efficacy and drug delivery technology in order to develop alternative treatments with better side-effects profiles, less toxicity, lower risk of resistance and are more cost-effective.

Mechanisms of Spontaneous Electrical Activity in the Developing Cerebral Cortex-Mouse Subplate Zone.

Subplate (SP) neurons exhibit spontaneous plateau depolarizations mediated by connexin hemichannels. Postnatal (P1-P6) mice show identical voltage pattern and drug-sensitivity as observed in slices from human fetal cortex; indicating that the mouse is a useful model for studying the cellular physiology of the developing neocortex. In mouse SP neurons, spontaneous plateau depolarizations were insensitive to blockers of: synaptic transmission (glutamatergic, GABAergic, or glycinergic), pannexins (probenecid), or calcium channels (mibefradil, verapamil, diltiazem); while highly sensitive to blockers of gap junctions (octanol), hemichannels (La3+, lindane, Gd3+), or glial metabolism (DLFC). Application of La3+ (100 µM) does not exert its effect on electrical activity by blocking calcium channels. Intracellular application of Gd3+ determined that Gd3+-sensitive pores (putative connexin hemichannels) reside on the membrane of SP neurons. Immunostaining of cortical sections (P1-P6) detected connexins 26, and 45 in neurons, but not connexins 32 and 36. Vimentin-positive glial cells were detected in the SP zone suggesting a potential physiological interaction between SP neurons and radial glia. SP spontaneous activity was reduced by blocking glial metabolism with DFLC or by blocking purinergic receptors by PPADS. Connexin hemichannels and ATP release from vimentin-positive glial cells may underlie spontaneous plateau depolarizations in the developing mammalian cortex.

Enhanced bioremediation of lindane-contaminated soils through microbial bioaugmentation assisted by biostimulation with sugarcane filter cake.

Lindane is a toxic and persistent organochlorine pesticide, whose extensive use generated its accumulation in different environmental matrices. Bioremediation is a promising technology that can be used combining bioaugmentation and biostimulation processes to soil restoration. The aim of the present work was to determine the conditions of maximum lindane removal by bioaugmentation with an actinobacteria consortium and biostimulation with sugarcane filter cake (SCFC). The assays were carried out on lindane-contaminated silty loam (SLS), clayey (CS), and sandy (SS) soils. Through complete factorial designs, the effects of three abiotic factors (moisture content, proportion and size of SCFC particles) were evaluated on lindane removal. In addition, a response optimizer determined the optimal conditions for pesticide removal in bioaugmented and biostimulated soils, in the range of levels studied for each factor. In these conditions, bioaugmentation of biostimulated soils increased the pesticide removal (SLS: 61.4%, CS: 70.8%, SS: 86.3%), heterotrophic microbial counts, and soil enzymatic activities, and decreased lindane T1/2, regarding the non-bioaugmented biostimulated controls, after 14 days of assay. The values of these parameters confirmed the efficiency of the bioremediation process. Finally, the viability of the four strains was demonstrated at the end of the assay. The results indicate that the simultaneous application of bioaugmentation with the actinobacteria consortium and biostimulation with SCFC constitutes a promising tool for restoring soils contaminated with lindane, by using the optimal conditions obtained through the factorial designs.

Recent Development on the Electrochemical Detection of Selected Pesticides: A Focused Review.

Pesticides are heavily used in agriculture to protect crops from diseases, insects, and weeds. However, only a fraction of the used pesticides reaches the target and the rest slips through the soil, causing the contamination of ground- and surface water resources. Given the emerging interest in the on-site detection of analytes that can replace traditional chromatographic techniques, alternative methods for pesticide measuring have recently encountered remarkable attention. This review gives a focused overview of the literature related to the electrochemical detection of selected pesticides. Here, we focus on the electrochemical detection of three important pesticides; glyphosate, lindane and bentazone using a variety of electrochemical detection techniques, electrode materials, electrolyte media, and sample matrix. The review summarizes the different electrochemical studies and provides an overview of the analytical performances reported such as; the limits of detection and linearity range. This article highlights the advancements in pesticide detection of the selected pesticides using electrochemical methods and point towards the challenges and needed efforts to achieve electrochemical detection suitable for on-site applications.

Thermally activated persulfate for the chemical oxidation of chlorinated organic compounds in groundwater.

Chlorinated pesticides were extensively produced in the XX century, generating high amounts of toxic wastes often dumped in the surroundings of the production sites, resulting in hot points of soil and groundwater pollution worldwide. This is the case of Bailín landfill, located in Sabiñánigo (Spain), where groundwater is highly polluted with chlorobenzenes (mono, di, tri and tetra) and hexachlorocyclohexanes. This study addresses the abatement of chlorinated organic compounds (COCs) present in the groundwater coming from the Bailín landfill by thermally activated persulfate, PS (TAP). The influence of temperature (30-50 °C) and oxidant concentration (2-40 g L-1) on the efficiency of COCs (initial concentration of COCs = 57.53 mg L-1, determined by the solubility of the pollutants in water) degradation has been investigated. Raising the reaction temperature and PS concentration the degradation of COCs significantly accelerates, as a result of higher production of sulfate radicals. The thermal activation of PS implies side reactions, involving the unproductive decomposition of this oxidant. The activation energy calculated for this reaction (128.48 kJ mol-1) reveals that is slightly more favored by temperature than the oxidation of COCs by sulfate radicals (102.4-115.72 kJ mol-1). At the selected operating conditions (PS = 10 g L-1, 40 °C), the almost complete conversion of COCs and a dechlorination and mineralization degree above 80% were obtained at 168 h reaction time. A kinetic model, able to adequately predict the experimental concentration of COCs when operating at different temperatures and initial concentration of PS has been proposed.

Bioremediation of lindane-contaminated soils by combining of bioaugmentation and biostimulation: Effective scaling-up from microcosms to mesocosms.

The scaling-up of lindane-contaminated soils bioremediation from microcosms to mesocosms bioaugmentated with an actinobacteria quadruple culture and biostimulated with sugarcane filter cake (SCFC) was surveyed. Mesocosms of silty loam soil, clayey soil, and sandy soil were polluted with the pesticide, bioaugmented with the mixed culture, biostimulated with adequate amounts of 0.5 mm SCFC particles, and assessed during 63 days maintaining environmental parameters with minimal intervention. Samples were taken to determine residual lindane, heterotrophic microorganisms, enzymatic activities, and bioremediation effectiveness using ecotoxicity tests with Raphanus sativus, Lactuca sativa, and Lycopersicon esculentum. The bioaugmentation and biostimulation of the three soils improved lindane removal, microbial counts, and enzymatic activities, and reduced pesticide T1/2, regarding the values obtained in non-bioremediated controls. The removal process was significantly affected by the soil type, and the highest pesticide dissipation (82.6%) was detected in bioremediated sandy soil. Ecotoxicity tests confirmed the bioremediation success through a rise in the vigor index of seedlings compared to non-treated soils (R. sativus: 12-22%; L. sativa: 12-20%; L. esculentum: 30-45%). Finally, scanning electron microscopy corroborated soil colonization by actinobacteria. Successful scaling-up of the combined application of an actinobacteria quadruple culture and SCFC as an appropriate strategy for restoring lindane-polluted soils at mesocosms-scale was confirmed.

Overexpression of cerebral cytochrome P450s in prenatally exposed offspring modify the toxicity of lindane in rechallenged offspring.

Prenatal exposure to low doses of lindane, an organochlorine insecticide used in public health and agriculture, induced a persistent increase in the expression of cerebral cytochrome P450s (CYPs) in rat offspring and modify the adult response to a later exposure of xenobiotics. To understand the mechanism involved in the modification of adult response, rat offspring exposed prenatally to lindane (p.o.; 0.25 mg/kg b.wt. from gestation day 5-21) were rechallenged with lindane (p.o.; 5 mg/kg X 5 days) postnatally at 9- or 18- or 27 weeks. The greater magnitude of increase in the expression of cerebral CYPs in rechallenged offspring and decline in the magnitude of increase in CYPs with increasing age correlated with the amount of lindane accumulating in the brain. Significant alterations in the circulatory levels of hormones in the rechallenged offspring suggest that these alterations may partly account for the persistence in the increase in the cerebral CYPs during development. Epigenetic data further revealed alterations in histone H3 acetylation and DNA methylation in promoter regions of cerebral CYPs isolated from rechallenged offspring at 9- or 18- or 27 weeks. Bisulphite sequencing revealing critical CpG methylation changes in the promoter regions in rechallenged offspring at 9 weeks demonstrated imprinting of the cerebral CYPs. Further, a greater magnitude of increase in apoptosis in the brain of rechallenged offspring has suggested that enhanced responsiveness of cerebral CYPs, which may result due to alterations in circulatory hormones, increased accumulation of lindane in the brain and epigenetic regulation of CYPs, is of toxicological relevance.

Efficacy and safety of antiscabietic agents: A systematic review and network meta-analysis of randomized controlled trials.

BACKGROUND: Many drugs have been used to treat scabies, but it is unclear which of them is the most efficacious. OBJECTIVE: To evaluate the comparative efficacy and safety of antiscabietic agents. METHODS: A systematic review of randomized controlled trials was conducted. Direct and network meta-analyses were applied to 13 antiscabietic agents on 3 outcomes (cure, persistent itching, and adverse events). Their probability of having highest efficacy and safety was estimated and ranked. RESULTS: A network meta-analysis of 52 trials including 9917 patients indicated that permethrin (the reference treatment) had a significantly higher cure rate than sulfur, malathion, lindane, crotamiton, and benzyl benzoate. Combination permethrin plus oral ivermectin had a nonsignificantly higher cure rate than permethrin. Combination permethrin plus oral ivermectin was ranked highest in terms of cure, topical ivermectin in terms of persistent itching, and synergized pyrethrins in terms of adverse events. On the basis of clustered ranking, permethrin, oral ivermectin, and synergized pyrethrins seemed to retain balance between cure and adverse events. LIMITATIONS: There are small numbers of trials and patients in some comparisons and a high risk of bias in some trials. CONCLUSION: There is no 1 treatment that ranked highest in all aspects. Physicians should consider the drug's efficacy and safety profiles, along with ease of administration.

Examining the role of total organic carbon and black carbon in the fate of legacy persistent organic pollutants (POPs) in indoor dust from Nepal: Implication on human health.

Despite the fact that the consumption and import of legacy persistent organic pollutants (POPs) have been stopped in Nepal since 2001, they are still of worry for human prosperity and the environment because of their persistence behavior and constant release from sources that are presently being used. The essential objective of this study was to assess the concentration and spatial distribution of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in residential dust from Nepal keeping in mind the end goal to evaluate the importance of total organic carbon (TOC) and black carbon (BC) in the fate of legacy POPs. Additionally, health risk exposure via dust ingestion and dermal absorption was estimated to evaluate the significance of dust media for human exposure. Results demonstrated that ∑OCPs in dust was 37 times greater than ∑PCBs. DDT was mostly dominated in the dust, and contributed 90% of the ∑OCPs, while hexa-CBs predominated among PCBs and represented 34% of ∑PCBs. Birgunj and Biratnagar had a relatively higher level of ∑OCPs and ∑PCBs than those of Kathmandu and Pokhara. TOC and BC showed a poor connection with OCPs, recommending little or no role. However, PCB in the dust, especially low congeners was strongly linked with TOC but not BC indicating the significant role of TOC. The daily risk exposure estimation indicated dermal absorption through dust as the principal means of OCPs/PCBs intake to both adult and children population. These estimated exposures were 2-4 orders of magnitude inferior to their corresponding reference dose showing insignificant risk.

Lindane degradation by root epiphytic bacterium Achromobacter sp. strain A3 from Acorus calamus and characterization of associated proteins.

Lindane degrading root epiphytic bacteria were isolated from wetland plant Acorus calamus. Bacterial strain A3 identified as Achromobacter sp. A3, showed maximum degradation potential of 88.7 ± 1.24% for 50 mg l-1 lindane. Lindane biodegradation was followed by decrease in pH as well as increase in concentration of chloride ions in the culture medium. Lindane degradation potential of Achromobacter sp. A3 was also studied at different concentrations of lindane. Maximum degradation was at 10 mg l-1 followed by 50 mg l-1 and 100 mg l-1 lindane. Also, lindane induced proteins were studied using SDS-PAGE. The induced proteins were identified as alpha/beta hydrolase fold-3 domain-containing protein, involved in lindane hydrolysis and extracellular solute-binding family protein having role in transmembrane transport of lindane for utilization of lindane by bacteria. The appearance of unique polypeptides in lane corresponding to media supplemented with lindane showed that the exposure of bacterial cells to lindane has resulted in regulative expression of certain proteins. So far as known, this is the first report to isolate and study lindane degrading root epiphytic bacteria from A. calamus.

Anaerobic biotransformation of hexachlorocyclohexane isomers by Dehalococcoides species and an enrichment culture.

The biotransformation of hexachlorocyclohexane isomers (HCH) by two Dehalococcoides mccartyi strains (195 and BTF08) and an enrichment culture was investigated and compared to conversion by the obligate anaerobic strain Clostridium pasteurianum strain DSMZ 525. The D. mccartyi strains preferentially transformed γ-HCH over α-HCH and δ-HCH isomers while ß-HCH biotransformation was not significant. In case of the enrichment culture, γ-HCH was preferentially transformed over the δ-HCH, ß-HCH and α-HCH isomers. Major observed metabolites in both cases were tetrachlorocyclohexene and as end products monochlorobenzene (MCB) and benzene. Dechlorination of the γ-HCH isomer was linked to an increase in cell numbers for strain 195. γ-HCH transformation was linked to considerable carbon stable isotope fractionation with the enrichment factor εc = - 5.5 ± 0.8‰ for D. mccartyi strain 195, εc = - 3.1 ± 0.4‰ for the enrichment culture and εc = - 4.1 ± 0.6‰ for co-metabolic transformation by C. pasteurianum.

In vitro efficacy of amitraz, coumaphos, deltamethrin and lindane against engorged female Rhipicephalus (Boophilus) annulatus and Haemaphysalis bispinosa ticks.

The present study compares the in vitro efficacy of four chemical acaricides, viz. amitraz, coumaphos, deltamethrin and lindane, against Rhipicephalus (Boophilus) annulatus and Haemaphysalis bispinosa ticks based on adult immersion tests. Amitraz, at 350 ppm, elicited 29.2 ± 4.17% mortality against R. (B.) annulatus, 100% inhibition of fecundity and absence of hatching of eggs laid by treated ticks. The same compound at 300 ppm caused 62.5 ± 12.5% mortality against H. bispinosa, 96.7% inhibition of fecundity and complete blocking of eclosion. The LC50 value of amitraz against susceptible H. bispinosa was 181 ppm. Deltamethrin at 400 ppm, elicited 25.0 ± 4.81% adult R. (B.) annulatus mortality, 97.5% inhibition of fecundity and absence of egg hatching. Complete blocking of egg hatching was observed even at 30 ppm. However, deltamethrin (at 50 ppm) elicited 75.0 ± 10.76% mortality against H. bispinosa, 65.8% inhibition of fecundity and very low egg hatching (10%). The LC50 for deltamethrin against susceptible H. bispinosa was 33.8 ppm. Coumaphos at 50 ppm, caused mortality of 70.8 ± 4.17% with R. (B.) annulatus whereas 100% mortality was observed against H. bispinosa. The LC50 values of coumaphos against R. (B.) annulatus and H. bispinosa were 9 and 8.75 ppm, respectively. Complete inhibition (100%) of fecundity was observed even at 30 ppm against both parasites. Complete blocking of egg hatching was also observed even at 10 ppm of coumaphos. Lindane at 1000 ppm caused mortality of 87.5 ± 7.98% against R. (B.) annulatus and 83.3% mortality against H. bispinosa at 100 ppm. The LC50 values of lindane against R. (B.) annulatus and H. bispinosa were 157 and 8.61 ppm, respectively. Complete inhibition of fecundity was observed with R. (B.) annulatus treated with lindane above 200 ppm and with H. bispinosa at a concentration above 50 ppm. Complete blocking of egg hatching was observed in R. (B.) annulatus, even at 100 ppm. Lindane caused 100% blocking of egg hatching at 1 ppm in the case of H. bispinosa.