Acaricide resistance and novel photosensitizing approach as alternative acaricides against the camel tick, Hyalomma dromedarii.

The control of the camel tick, Hyalomma dromedarii is very crucial. This study evaluated the novel toxicity of photosensitizers and Phoxim insecticide against H. dromedarii males using the adult immersion tests. Ticks were subjected to sunlight for 10 min post-treatment (PT). The optical characters of the applied materials were determined by UV-Vis spectroscopy (250-900 nm wavelengths). The intensity of spectra decreased as dye concentration decreased. The optical bandgap energies of the dyes at different concentrations were not changed as the concentration changed and decreased as the absorption peak of individual dyes red-shifted. The mortalities 72 h PT reached 42.2%, 44.4%, 51.1%, 71.1%, 46.7%, 48.9%, 44.4%, and 55.6% for chlorophyllin, echinochrome, field stain, methylene blue, phthalocyanine, rhodamine 6G, riboflavin, and safranin, respectively. Methylene blue recorded the highest median lethal concentration (LC50 = 127 ppm) followed by safranin, field stain, rhodamine 6G, phthalocyanine, echinochrome riboflavin, and chlorophyllin (LC50 = 209, 251, 271, 303, 324, 332, and 362 ppm, respectively, 72 h PT). Their median lethal time, LT50, values PT with 240 ppm were 45, 87, 96, 72, 129, 115, 131, and 137 h, respectively. The relative toxicities of the LC50 values 72 h PT showed that chlorophyllin, echinochrome, field stain, methylene blue, phthalocyanine, rhodamine 6G, riboflavin, and safranin were 3.2, 3.6, 4.6, 9.1, 3.8, 4.3, 3.5, and 5.6 times, respectively, more effective than Phoxim. Methylene blue, safranin, and field stain showed a broad absorbance area indicating a large photoactivity and better phototoxicity and could be used as alternative agents to synthetic acaricides.

Nanostructured Lipid Carriers (NLC) for Biologically Active Green Tea and Fennel Natural Oils Delivery: Larvicidal and Adulticidal Activities against Culex pipiens.

(1) Background: The control of mosquitoes with essential oils is a growing demand. (2) Methods: This study evaluated the novel larvicidal and adulticidal activity of fennel and green tea oils and their nanostructured lipid carriers (NLC) against Culex pipiens (C. pipiens) in the laboratory, field conditions and evaluated their effect against non-target organisms. SLN type II nanoformulations were synthesized and characterized using dynamic light scattering (DLS), zeta potential and transmission electron microscope. (3) Results: The synthesized NLCs showed spherical shaped, homogenous, narrow, and monomodal particle size distribution. The mortality percent (MO%) post-treatment (PT) with 2000 ppm for 24 h with fennel oil and NLC fennel (NLC-F) reached 85% (LC50 = 643.81 ppm) and 100% (LC50 = 251.71), whereas MO% for green tea oil and NLC green tea (NLC-GT) were 80% (LC50 = 746.52 ppm) and 100% (LC50 = 278.63 ppm), respectively. Field trial data showed that the larval reduction percent of fennel oil and NLC-F reached 89.8% and 97.4%, 24 h PT and the reduction percent of green tea oil and NLC-GT reached 89% and 93%, 24 h PT with persistence reached 8 and 7 days, for NLC-F and NLC-GT, respectively. The adulticidal effects showed that NLC-F and NLC-GT (100% mortality) were more effective than fennel and green tea oils (90.0% and 83.33%), with 24 h PT, respectively. Moreover, their reduction of adult density after spraying with LC95 X2 for 15 min, with fennel oil, NLC-F, and green tea oil, NLC-GT were 83.6%, 100%, 79.1%, and 100%, respectively, with persistence (>50%) lasting for three days. The predation rate of the mosquitofish, Gambusia affinis, and the bug, Sphaerodema urinator, was not affected in both oil and its NLC, while the predation rate of the beetle, Cybister tripunctatus increased (66% and 68.3%) by green tea oil and NLC-GT, respectively. (4) Conclusions: NLCs nanoformulation encapsulated essential oils was prepared successfully with unique properties of size, morphology, and stability. In vitro larvicidal and adulticidal effects against C. pipiens supported with field evaluations have been performed using essential oils and their nanoformulations. The biological evaluation of nanoformulations manifested potential results toward both larvicidal and adulticidal compared to the essential oils themselves, especially NLC encapsulated fennel oil which had promising larvicidal and adulticidal activity.

Mg-LDH Nanoclays Intercalated Fennel and Green Tea Active Ingredient: Field and Laboratory Evaluation of Insecticidal Activities against Culex pipiens and Their Non-Target Organisms.

(1) Background: Mosquito control with essential oils is a growing demand. This work evaluated the novel larvicidal and adulticidal activity of fennel and green tea oils and their Layered double hydroxides (LDHs) nanohybrid against Culex pipiens (Cx. pipiens) in both laboratory and field conditions and evaluated their effect against non-target organisms; (2) Methods: Two types of nanoclays, MgAl-LDH and NiAl-LDH were synthesized and characterized using PXRD, TEM and SEM, whereas their elemental analysis was accomplished by SEM-EDX; (3) Results: Mg and Ni LDHs were synthesized by the co-precipitation method. The adsorption and desorption of active ingredients were conducted using LC MS/MS, with reference to the SEM-EXD analysis. The desorption process of MgAl-LDH intercalated green tea oil was conducted using ethanol, and reveled significant peaks related to polyphenols and flavonoids like Vanillin, Catechin, Daidzein, Ellagic acid, Naringenin, Myricetin and Syringic acid with concentrations of 0.76, 0.73, 0.67, 0.59, 0.52, 0.44 and 0.42 µg/g, respectively. The larvicidal LC50 values of fennel oil, Mg-LDH-F, and Ni-LDH-F were 843.88, 451.95, 550.12 ppm, respectively, whereas the corresponding values of green tea were 938.93, 530.46, and 769.94 ppm. The larval reduction percentage of fennel oil and Mg-LDH-F reached 90.1 and 96.2%, 24 h PT and their persistence reached five and seven days PT, respectively. The reduction percentage of green tea oil and Mg-LDH-GT reached 88.00 and 92.01%, 24 h PT and their persistence reached five and six days PT, respectively. Against adults, Mg-LDH-GT and Ni-LDH-GT were less effective than green tea oil as their LC95 values were 5.45, 25.90, and 35.39%, respectively. The reduction in adult density PT with fennel oil, Mg-LDH-F, green tea oil, and Mg-LDH-GT reached 83.1, 100, 77.0, and 99.0%, respectively, 24 h PT and were effective for three days. Mg-LDH-GT and Mg-LDH-F increased the predation Cybister tripunctatus (71% and 69%), respectively; (4) Conclusions: For the first time, Mg-LDH-GT and Mg-LDH-F was the best system loaded with relatively good desorption release to its active ingredients and significantly affected Cx. pipiens larvae and adults in both laboratory and field circumstances, and it could be included in mosquito control.

Larvicidal activity of Acacia nilotica extracts against Culex pipiens and their suggested mode of action by molecular simulation docking.

Mosquitoes are one of the deadliest and most hazardous animals on Earth, where they transmit several diseases that kill millions of people annually. There is an ongoing search almost everywhere in the world for more effective and contemporary ways to control mosquitoes other than pesticides. Phytochemicals are affordable, biodegradable biological agents that specialize in eliminating pests that represent a risk to public health. The effectiveness of Acacia nilotica methanol and aqueous leaf extracts against 4th instar larvae was evaluated. The results revealed that the methanol extract of A. nilotica had a noticeable influence on the mortality rate of mosquito larvae, especially at high concentrations. Not only did the mortality rate rise significantly, but the hatching of the mosquito eggs was potentially suppressed.Terpenes, fatty acids, esters, glycosides, pyrrolidine alkane, piperazine, and phenols were the most prevalent components in the methanol extract, while the aqueous extract of A. nilotica exclusively showed the presence of fatty acids. The insecticidal susceptibility tests of both aqueous and alcoholic extract of A. nilotica confirmed that the Acacia plant could serves as a secure and efficient substitute for chemical pesticides because of its promising effect on killing larvae and egg hatching delaying addition to their safety as one of the natural pesticides. Molecular docking study was performed using one of the crucial and life-controlling protein targets, fatty acid binding protein (FABP) and the most active ingredients as testing ligands to describe their binding ability. Most of the structurally related compounds to the co-crystallized ligand, OLA, like hexadecanoic acid furnished high binding affinity to the target protein with very strong and stable intermolecular hydrogen bonding and this is quite similar to OLA itself. Some other structural non-related compounds revealed extraordinarily strong binding abilities like Methoxy phenyl piperazine. Most of the binding reactivities of the majortested structures are due to high structure similarity between the positive control, OLA, and tested compounds. Such structure similarity reinforced with the binding abilities of some detected compounds in the A. nilotica extract could present a reasonable interpretation for its insecticidal activity via deactivating the FABP protein. The FABP4 enzyme inhibition activity was assessed for of both methanolic and aqueous of acacia plant extract and the inhibition results of methanol extract depicted noticeable potency if compared to orlistat, with half-maximal inhibitory concentration (IC50) of 0.681, and 0.535 µg/ml, respectively.

Acaricidal Efficacy of Thirty-Five Egyptian Plants Against the Camel Tick, Hyalomma Dromedarii.

PURPOSE: Alternative and affordable tick control strategies are crucial to control and prevent tick bites and tick-borne diseases. METHODS: In this study, we evaluated the acaricidal efficacy of 35 aqueous plant extracts (17%) against the camel tick, Hyalomma dromedarii. RESULTS: The phytochemical profile indicated the presence of various secondary substances. Plants were classified into three groups according to their mortality percentage 15 days post-treatment with 17%. This highly effective group (91%-95%) comprised Ocimum basilicum, Mespilus germanica, and Viola alpine followed by Carum carvi, Cucurbita pepo (peel), and Peganum harmala. A moderately effective group (80%-90%) included Acacia nilotica, Apium graveolens, Capsicum annuum, Ceratonia siliqua, Cucurbita pepo (seeds), Equisetum arvense, Eruca sativa, Ginkgo biloba, Plantago psyllium, Phyllanthus emblica, Punica granatum, and Ziziphus spinachristi. The 20 remaining plants were assigned to the less effective group (< 80%). Viscum album (58.3%), which was the least effective reference plant. The high potency of six plant extracts as acaricides may be attributed to the high content of active principles, e.g., phenols, flavonoids, and tannins. CONCLUSION: All of these highly effective plants are recommended for use as an acaricide, in case of facing acaricidal resistance or limited options for tick control.

The potential biological activities of Aspergillus luchuensis-aided green synthesis of silver nanoparticles.

Biosynthetic metals have attracted global attention because of their safety, affordability, and environmental friendliness. As a consequence, the cell-free filtrate (CFF) of Dill leaf-derived endophytic fungus Aspergillus luchuensis was employed for the extracellularly synthesis silver nanoparticles (AgNPs). A reddish-brown color shift confirmed that AgNPs were successfully produced. The obtained AgNPs were characterized by UV-Vis (ultraviolet-visible spectroscopy), Transmission electron microscopy (TEM), FTIR, EDX, and zeta potential. Results demonstrated the creation of crystalline AgNPs with a spherical shape at 427.81 nm in the UV-Vis spectrum, and size ranged from 16 to 18 nm as observed by TEM. Additionally, the biogenic AgNPs had a promising antibacterial activity versus multidrug-resistant bacteria, notably, S. aureus, E. coli, and S. typhi. The highest growth reduction was recorded in the case of E. coli. Furthermore, the biosynthesized AgNPs demonstrated potent antifungal potential versus a variety of harmful fungi. The maximum growth inhibition was evaluated from A. brasinsilles, followed by C. albicans as compared to cell-free extract and AgNO3. In addition, data revealed that AgNPs possess powerful antioxidant activity, and their ability to scavenge radicals increased from 33.0 to 85.1% with an increment in their concentration from 3.9 to 1,000 µg/mL. Furthermore, data showed that AgNPs displayed high catalytic activity of safranin under light irradiation. The maximum decolorization percentage (100%) was observed after 6 h. Besides, the biosynthesized AgNPs showed high insecticidal potential against 3rd larval instar of Culex pipiens. Taken together, data suggested that endophytic fungus, A. luchuensis, is an attractive candidate as an environmentally sustainable and friendly fungal nanofactory.

Synthesis of eco-friendly layered double hydroxide and nanoemulsion for jasmine and peppermint oils and their larvicidal activities against Culex pipiens Linnaeus.

Mosquito-borne diseases represent a growing health challenge over time. Numerous potential phytochemicals are target-specific, biodegradable, and eco-friendly. The larvicidal activity of essential oils, a jasmine blend consisting of Jasmine oil and Azores jasmine (AJ) (Jasminum sambac and Jasminum azoricum) and peppermint (PP) Mentha arvensis and their nanoformulations against 2nd and 4th instar larvae of Culex pipiens, was evaluated after subjecting to different concentrations (62.5, 125, 250, 500, 1000, and 2000 ppm). Two forms of phase-different nanodelivery systems of layered double hydroxide LDH and oil/water nanoemulsions were formulated. The synthesized nanoemulsions showed particle sizes of 199 and 333 nm for AJ-NE and PP-NE, with a polydispersity index of 0.249 and 0.198, respectively. Chemical and physiochemical analysis of TEM, SEM, XRD, zeta potential, drug loading capacity, and drug release measurements were done to confirm the synthesis and loading efficiencies of essential oils' active ingredients. At high concentrations of AJ and PP nanoemulsions (2000 ppm), O/W nanoemulsions showed higher larval mortality than both LDH conjugates and crude oils. The mortality rate reached 100% for 2nd and 4th instar larvae. The relative toxicities revealed that PP nanoemulsion (MA-NE) was the most effective larvicide, followed by AJ nanoemulsion (AJ-NE). There was a significant increase in defensive enzymes, phenoloxidase, and α and ß-esterase enzymes in the treated groups. After treatment of L4 with AJ, AJ-NE, PP, and PP-NE, the levels of phenoloxidase were 545.67, 731.00, 700.00, and 799.67 u/mg, respectively, compared with control 669.67 u/mg. The activity levels of α-esterase were 9.71, 10.32, 8.91, and 10.55 mg α-naphthol/min/mg protein, respectively. It could be concluded that the AJ-NE and PP-NE nanoformulations have promising larvicidal activity and could act as safe and effective alternatives to chemical insecticides.

Efficacy of Acacia nilotica, Eucalyptus camaldulensis, and Salix safsafs on the mortality and development of two vector-borne mosquito species, Culex pipiens and Aedes aegypti, in the laboratory and field.

Mosquitoes are one of the most lethal animals in the world and transmit many dangerous human pathogens, causing millions of deaths each year. The search for modern and better mosquito control is an endless effort almost all over the world. Phytochemicals are promising biological agents for getting rid of pests that are harmful to human and animal health and crops, they are inexpensive, biodegradable, and have diverse modes of action. The efficacy of acetone and hexane leaf extracts of Acacia nilotica, Eucalyptus camaldulensis, and Salix safsafs was investigated against the 2nd and 4th larvae and pupae of two vectors, Culex pipiens and Aedes aegypti. The results showed the obvious effect of A. nilotica extract on the mortality of mosquito larvae, the reduction of female eggs, and a higher mortality rate in sunlight than in shadow (fluorescein). Data from field trials revealed that A. nilotica extracts had the greatest effect on larval reduction, reaching 89.8% in 24 h and having a 12-day stability. Polyethylene glycol, sesquiterpenes, and fatty acids were the most common compounds found in A. nilotica, E. camaldulensis, and S. safsafs, respectively. The acacia plant had promising larvicidal activity, safe and effective alternative to chemical insecticides.

Efficacy of alumina nanoparticles as a controllable tool for mortality and biochemical parameters of Culex pipiens.

Mosquitoes still pose a clear risk to human and animal health. Recently, nanomaterials have been considered one of the cost-effective solutions to this problem. Therefore, alumina nanoparticles (Al) were synthesized using an auto-combustion method, followed by calcination at 600 and 800 °C. Glucose (G) and sucrose (Su) were used as fuels and the combustion was performed at pH 2, 7, and 10. The as-synthesized Al2O3 nanoparticles were characterized by XRD, FTIR, SEM, and TEM. Alumina nanoparticles prepared using G and Su fuels at pH 7 and 800 °C (Al-G7-800 and Al-Su7-800) have crystallite sizes of 3.9 and 4.05 nm, respectively. While the samples (Al-G7-600 and Al-Su7-600) synthesized at pH 7 and 600 °C were amorphous. The prepared alumina nanoparticles were applied to the larval and pupal stages of Culex pipiens. The results showed that alumina nanoparticles cause higher mortality in the 1st larval instar than in all other larval instars and pupal stages of Culex pipiens after treatment at a high concentration of 200 ppm. Additionally, the larval duration after treatment with LC50 concentrations of alumina (Al-G7-800 and Al-Su7-800) was 31.7 and 23.6 days, respectively, compared to the control (13.3 days). The recorded data found that the content of glutathione-S-transferase, alkaline/acid phosphatase, ß/α-esterase, and total protein were altered upon treatment with the LC50 concentration of alumina (Al-G7-800) nanoparticles. Based on these findings, alumina nanoparticles are a promising candidate as a potential weapon to control pests and mosquitoes.

Novel acaricidal and growth-regulating activity of Aloe vera and Rheum rhabarbarum extracts and their oil/water nanoemulsions against the camel tick, Hyalomma dromedarii.

Hyalomma dromedarii is an important tick species infesting livestock. This work evaluated the novel adulticidal, insect growth-regulating, and enzymatic efficacy of ethanol plant extracts of Aloe vera and Rheum rhabarbarum and their nanoemulsions against males and engorged females of the camel tick, H. dromedarii. The physicochemical properties of nanoemulsions were evaluated. The High-Performance Liquid Chromatography (HPLC) analyses indicated that the extracts contained polyphenols and flavonoids, which could enhance their acaricidal effect. Dynamic light scattering (DLS) of the nanoemulsions of A. vera and R. rhabarbarum were 196.7 and 291 nm, whereas their zeta potentials were - 29.1 and - 53.1 mV, respectively. Transmission electron microscope (TEM) indicated that nanoemulsions showed a regular spherical shape (less than 100 nm). Fifteen days post-treatment (PT) with 25%, the mortality% of A. vera and R. rhabarbarum were 88.5 and 96.2%, respectively. Five days PT, the median lethal concentration values of A. vera, R. rhabarbarum, and their nanoemulsions were 7.8, 7.1, 2.8, and 1.02%, respectively, and their toxicity indices were 91.02, 100, 36.4, and 100%, respectively. Their median lethal time values PT with 3.5% were 6.09, 5.09, 1.75, and 1.34 days, respectively. Nanoemulsions enhanced the efficacy of the crude extract 1-7 folds, 5 days PT, and accelerated their speed of killing ticks 2-4 times. The total protein and carbohydrates, Acetylcholinesterase, Alpha esterase, and Amylase were affected PT. The reproductive potential of engorged females was adversely impacted. In conclusion, the novel A. vera and R. rhabarbarum extracts were promising acaricides, and their nanoformulations enhanced their efficacies.

Sustainable Pest Management Using Novel Nanoemulsions of Honeysuckle and Patchouli Essential Oils against the West Nile Virus Vector, Culex pipiens, under Laboratory and Field Conditions.

Essential oils are natural plant products that are very interesting, as they are important sources of biologically active compounds. They comprise eco-friendly alternatives to mosquito vector management, particularly essential oil nanoemulsion. Therefore, the aim of this study is to evaluate the effectiveness of 16 selected essential oils (1500 ppm) in controlling mosquitoes by investigating their larvicidal effects against the larvae and adults of the West Nile virus vector Culex pipiens L. (Diptera: Culicidae); the best oils were turned into nanoemulsions and evaluated under laboratory and field conditions. The results show that honeysuckle (Lonicera caprifolium) and patchouli (Pogostemon cablin) essential oils were more effective in killing larvae than the other oils (100% mortality) at 24 h post-treatment. The nanoemulsions of honeysuckle (LC50 = 88.30 ppm) and patchouli (LC50 = 93.05 ppm) showed significantly higher larvicidal activity compared with bulk honeysuckle (LC50 = 247.72 ppm) and patchouli (LC50 = 276.29 ppm) oils. L. caprifolium and P. cablin (100% mortality), followed by Narcissus tazetta (97.78%), Rosmarinus officinalis (95.56%), and Lavandula angustifolia (95.55%), were highly effective oils in killing female mosquitoes, and their relative efficacy at LT50 was 5.5, 5.3, 5.8, 4.1, and 3.2 times greater, respectively, than Aloe vera. The results of the field study show that the honeysuckle and patchouli oils and their nanoemulsions reduced densities to 89.4, 86.5, 98.6, and 97.0% at 24 h post-treatment, respectively, with persistence for eight days post-treatment in pools. Nano-honeysuckle (100% mortality) was more effective than honeysuckle oils (98.0%). Our results show that honeysuckle and patchouli oils exhibited promising larvicidal and adulticidal activity of C. pipiens.

Larvicidal and adulticidal effects of some Egyptian oils against Culex pipiens.

Mosquitoes and mosquito-borne diseases represent an increasing global challenge. Plant extract and/or oils could serve as alternatives to synthetic insecticides. The larvicidal effects of 32 oils (1000 ppm) were screened against the early 4th larvae of Culex pipiens and the best oils were evaluated against adults and analyzed by gas chromatography-mass spectrometry (GC mass) and HPLC. All oils had larvicidal activity (60.0-100%, 48 h Post-treatment, and their Lethal time 50 (LT50) values ranged from 9.67 (Thymus vulgaris) to 37.64 h (Sesamum indicum). Oils were classified as a highly effective group (95-100% mortalities), including Allium sativum, Anethum graveolens, Camellia sinensis, Foeniculum vulgare, Nigella sativa, Salvia officinalis, T. vulgaris, and Viola odorata. The moderately effective group (81-92% mortalities) included Boswellia serrata, Cuminum cyminum, Curcuma aromatic, Allium sativum, Melaleuca alternifolia, Piper nigrum, and Simmondsia chinensis. The least effective ones were C. sativus and S. indicum. Viola odorata, Anethum graveolens, T. vulgaris, and N. sativa provide 100% adult mortalities PT with 10, 25, 20, and 25%. The mortality percentages of the adults subjected to 10% of oils (H group) were 48.89%, 88.39%, 63.94%, 51.54%, 92.96%, 44.44%, 72.22%, and 100% for A. sativum, An. graveolens, C. sinensis, F. vulgare, N. sativa, S. officinalis, T. vulgaris, and V. odorata, respectively. Camellia sinensis and F. vulgare were the most potent larvicides whereas V. odorata, T. vulgaris, An. graveolens and N. sativa were the best adulticides and they could be used for integrated mosquito control.

Ovicidal Aroma Shields for Prevention of Blow Fly Strikes Caused by Lucilia sericata (Meigen), Diptera: Calliphoridae.

The blow fly, Lucilia sericata (Meigen) (Diptera: Culicidae) is a primary facultative ectoparasite controlled by insecticides that have environmental and safety concerns; therefore, its natural and safe control is crucial. L. sericata eggs were subjected to 400 µL of 5% of 24 materials of plant-borne origin. The number of hatched and unhatched eggs were counted 24 h postexposure. Stopmyasis® expressed the highest ovicidal effect, followed by cedarwood, orange, and tea tree oils. The mean ovicidal results were 46.09-95.24% grouped as Class A, which provided the lowest hatchability rates. Even though benzoin, vanillin, citronella, and camphor oils grouped as Class B provided moderate ovicidal effects (33.69-43.92%), their efficacy differed significantly from those of the treatments in Classes A and C containing the control group and vetiver, eucalyptus, Olbas®, neem, sunflower, oil blends, patchouli, frankincense, p-menthane-3,8 diol (PMD), lavender, peppermint, cinnamon, calry sag, myrtle, and silicone oil. According to our knowledge, most (19 out of 24) applied materials were used as ovicides against L. serricata for the first time, except orange, eucalyptus, patchouli, cinnamon oils, and six of them were applied as ovicides against pests for the first time. Stopmyasis containing Géraniol and PMD is the drug of choice as an ecofriendly product to prevent blow fly strikes through correct diagnosis and prompt treatment preventing a disastrous and destructive course of the disease and improving quality of life.

Novel Pesticidal Efficacy of Araucaria heterophylla and Commiphora molmol Extracts against Camel and Cattle Blood-Sucking Ectoparasites.

Botanical insecticides are promising pest control agents. This research investigated the novel pesticidal efficacy of Araucaria heterophylla and Commiphora molmol extracts against four ectoparasites through treated envelopes. Seven days post-treatment (PT) with 25 mg/mL of C. molmol and A. heterophylla, complete mortality of the camel tick, Hyalomma dromedarii and cattle tick, Rhipicephalus (Boophilus) annulatus were reached. Against H. dromedarii, the median lethal concentrations (LC50s) of the methanol extracts were 1.13 and 1.04 mg/mL and those of the hexane extracts were 1.47 and 1.38 mg/mL, respectively. The LC50 values of methanol and hexane extracts against R. annulatus were 1.09 and 1.41 plus 1.55 and 1.08 mg/mL, respectively. Seven days PT with 12.5 mg/mL, extracts completely controlled Haematopinus eurysternus and Hippobosca maculata; LC50 of Ha. eurysternus were 0.56 and 0.62 mg/mL for methanol extracts and 0.55 and 1.00 mg/mL for hexane extracts, respectively, whereas those of Hi. maculata were 0.67 and 0.78 mg/mL for methanol extract and 0.68 and 0.32 mg/mL, respectively, for hexane extracts. C. molmol extracts contained sesquiterpene, fatty acid esters and phenols, whereas those of A. heterophylla possessed monoterpene, sesquiterpene, terpene alcohols, fatty acid, and phenols. Consequently, methanol extracts of C. molmol and A. heterophylla were recommended as ecofriendly pesticides.

Influence of Aquatain™, a monomolecular surface film on surface tension for controlling the filarial vector Culex pipiens (Diptera: Culicidae).

Surface tension is a phenomenon in the liquid media and plays an important part in the development and survival of aquatic animals. Influence of Aquatain™ monomolecular film on surface tension was determined against mosquito larvae and pupae at different temperatures (10, 15, 20, 25, 30 and 35 °C) and Aquatain™ doses (0.5, 1.0 and 2.0 ml/m2). In the laboratory, Aquatain™ showed larvicidal and pupicidal effects against the filarial vector Culex pipiens. Higher mortality was observed in late and more weighted instars/stages than young ones as well as in the pupal stage. The pupal mortality reached 76.2%, 86% and 93.3% after 12 h post-treatment at 0.5, 1.0 and 2.0 ml/m2, respectively, and it was completely eliminated (100%) within 24 h compared to 15.1%, 26.9% and 38.2% for 1st larval instar, respectively. Also, results showed at 0.5 ml/m2 with temperature range: 10, 15, 20, 25, 30 and 35 °C, the mortality reached 4.0, 6.7, 10.8, 17.3, 22.7, 29.3% and 32, 44, 54, 72, 84, 97.3% for 1st and 4th larval instar, respectively, where the surface tension (γ) was 65.6, 62.4, 58.0, 57.0, 54.2 and, 49.6 dyn/cm, while the Aquatain™ was more effective on mosquito larvae and pupae at high doses with the temperature range. On the other hand, without Aquatain™ dose, the mortality value ranged between 0.0 - 1.2%, and the surface tension (γ) was 74.5 dyne/cm, which is considered as an accidental death. Aquatain™ was effective against all aquatic phases of mosquitoes, especially against the last and weighted ones. Not only was the efficacy of Aquatain™ increased by increasing the dose, but it also increased with the increased temperature of the environment. This efficiency of Aquatain™ is due to its ability to reduce the surface tension of the water medium, preventing different stages of mosquitoes from reaching the surface for breathing thereby leading to suffocation and death. Therefore, we recommended Aquatain™ in programmes for mosquito control and other aquatic insects as a safe, cost-effective control agent.

Climatic factors influencing the abundance of Phlebotomus papatasi (Scopoli) (Diptera: Psychodidae) in the Nile Delta.

Ecological studies on sand flies were carried out in two villages of the Nile Delta Governorates namely; Kafr Tahla (Qalyubiya) and el Quantara el Beida (Kafr el-Sheikh) from September 2003 to August 2005. Sand flies were collected weekly from around houses, stables and near rodent burrows using sticky paper traps. A total of 9529 sand flies were collected from the two villages, all of which were identified as Phlebotomus papatasi. Sand fly activity started from April to December with a bimodal annual pattern. The sex ratio of collected sand flies was significantly male biased. Data analyses revealed that sand fly densities were strongly correlated to temperature but not to relative humidity or wind velocity. Variation in the densities of P. papatasi in both villages did not show a significant effect due to lunar phases. However, sand fly activity was highly positively correlated to fraction illumination.